ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Immunocytochemistry  (262)
  • phosphorus  (206)
  • Springer  (468)
  • National Academy of Sciences
  • 1990-1994  (468)
Collection
Keywords
Publisher
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Microfilaments (F-actin) in generative cells and sperm: an evaluation (1992)
    Springer
    Sexual plant reproduction 5 (1992), S. 89-100 
    Details
    ISSN: 1432-2145
    Keywords: Actin ; Cytoskeleton ; Generative cell ; Immunocytochemistry ; Microtubule ; Mitosis ; Phragmoplast ; Pollen ; Rhodamine phalloidin ; Sperm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Disagreement has arisen over the presence of actin-containing microfilaments (Mfs) in angiosperm generative cells and sperm (GSP). In order to address this issue, we subjected GSP of Tradescantia virginiana, Nicotiana tabacum and Rhododendron laetum to a series of localizations using different antiactins, rhodamine phalloidin and antimyosin. Coordinate staining with antitubulin and Hoechst 33258 defined the status of the microtubule (Mt) cytoskeleton and stages of generative cell division. Additional experiments utilized cytochalasin D (CD). In no instance could Mfs be detected in GSP of the three species. Instead, Mfs seen at the periphery of GSP appear to be continuous with vegetative Mfs and thus are in the vegetative cytoplasm. Mfs are not seen in the constriction zone of dividing T. virginiana generative cells, nor are they indicated in the phragmoplast of N. tabacum and R. laetum. Myosin localizations reveal punctate staining in the vegetative cytoplasm and a thin line of fluorescence around the the outside of the generative cell. While CD seems to delay generative cell division, cytokinesis still takes place. CD-induced Mf fragments are evident in the vegetative cytoplasm but not in GSP. The weight of evidence therefore indicates that GSP do not contain Mfs. The implications of this conclusion for the behavior of GSP and the mechanism of cytokinesis in dividing generative cells are considerable.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00194867
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Occurrence and expression of acid phosphatase of Hymenoscyphus ericae (Read) Korf & Kernan, in isolation or associated with plant roots (1992)
    Springer
    Mycorrhiza 1 (1992), S. 137-146 
    Details
    ISSN: 1432-1890
    Keywords: Ericaceae ; Mycorrhizal fungi ; Acid phosphatase ; Protein expression ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The activity of acid phosphatase produced in pure culture by the endomycorrhizal fungus Hymenoscyphus ericae (Read) Korf & Kernan (H. ericae LPA 2) was inhibited by high phosphorus levels, alkaline pH, fluoride, molybdate and mannosidase, and activated by concanavalin A. Over 80% of the enzyme activity was due to two wall-bound acid phosphatase isozymes with the characteristics of mannose-rich glycoproteins. Antiserum was raised against the major, low-molecular-weight wall isozyme and its activity tested by immunoblotting and ELISA. The antiserum cross reacted 100% with exocellular (excreted) and 28% with cytoplasmic cellular fractions of H. ericae (LPA 2) cultures, and showed high reactivity with other strains of H. ericae but not with fungal isolates from Erica hispidula L. or E. mauritanica L. Ultrastructural localization of acid phosphatase by cytoenzymology and indirect immunogold labelling confirmed its association with the fungal wall in pure culture and showed that the influence of a high phosphorus level, fluoride and molybdate is through inactivation of the enzyme. Intense acid phosphatase activity, sensitive to the latter inhibitors, was also present on external hyphae growing over a host or non-host root but it was weak or absent from intracellular hyphae where these developed within a host root. Indirect immunolabelling confirmed that this acid phosphatase was of fungal origin and that the specific inhibitory effect of host cells is due to inactivation of the enzyme rather than repression of its synthesis. Possible implications of fungal acid phosphatase in ericoid endomycorrhizal infection processes are discussed together with mechanisms that may be regulating the enzyme activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00203287
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Peptidergic motoneurons in the buccal ganglia of Aplysia californica Immunocytochemical, morphological, and physiological characterizations (1991)
    Springer
    Journal of comparative physiology 168 (1991), S. 323-336 
    Details
    ISSN: 1432-1351
    Keywords: Aplysia ; Motoneurons ; Immunocytochemistry ; Small cardioactive peptides ; Facilitation ; Depression ; Buccal ; Feeding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary We used physiological recordings, intracellular dye injections and immunocytochemistry to further identify and characterize neurons in the buccal ganglia of Aplysia calif ornica expressing Small Cardioactive Peptide-like immunoreactivity (SCP-LI). Neurons were identified based upon soma size and position, input from premotor cells B4 and B5, axonal projections, muscle innervation patterns, and neuromuscular synaptic properties. SCP-LI was observed in several large ventral neurons including B6, B7, B9, B10, and B11, groups of s1 and s2 cluster cells, at least one cell located at a branch point of buccal nerve n2, and the previously characterized neurons B1, B2 and B15. B6, B7, B9, B10 and B11 are motoneurons to intrinsic muscles of the buccal mass, each displaying a unique innervation pattern and neuromuscular plasticity. Combined, these motoneurons innervate all major intrinsic buccal muscles (I1/I3, I2, I4, I5, I6). Correspondingly, SCP-LI processes were observed on all of these muscles. Innervation of multiple nonhomologous buccal muscles by individual motoneurons having extremely plastic neuromuscular synapses, represents a unique form of neuromuscular organization which is prevalent in this system. Our results show numerous SCPergic buccal motoneurons with widespread ganglionic processes and buccal muscle innervation, and support extensive use of SCPs in the control of feeding musculature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00198352
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Opsin localization and chromophore retinoids identified within the basal brain of the lizard Anolis carolinensis (1993)
    Springer
    Journal of comparative physiology 172 (1993), S. 33-45 
    Details
    ISSN: 1432-1351
    Keywords: Photoreception ; Extraretinal Photoreceptor ; Chromophore ; Opsin ; Reptile ; Immunocytochemistry ; HPLC
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Since the beginning of this century evidence has accumulated which demonstrates that non-mammalian vertebrates possess photoreceptors situated deep within the brain. While many attempts have been made to localize these sensory cells, studies have either failed or been inconclusive. In this report we have used several experimental approaches to localize the deep brain photoreceptors of the lizard Anolis carolinensis. Using 3 antibodies that bind vertebrate cone opsins, we have immunolabelled cerebrospinal fluid (CSF)-contacting neurons located at the ventricular border within the nucleus ventromedialis of the septum. Western blot analysis indicates that these antibodies recognized a single 40 kD protein in ocular, anterior brain, and pineal extracts. Immunoblots of rodent brain did not show a similar protein band. We have also identified specific retinoids associated with phototransduction (11-cis and all-trans-3,4-didehydroretinaldehyde) within anterior brain extracts. This combined data provides the most detailed analysis of deep brain photoreceptors in any vertebrate. Consequently, we feel Anolis provides an excellent model to study this unexplored sensory system of the vertebrates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214713
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Isolation of an egg-laying hormone-binding protein from the gonad of Aplysia californica and its localization in oocytes (1993)
    Springer
    Journal of comparative physiology 173 (1993), S. 475-483 
    Details
    ISSN: 1432-1351
    Keywords: Egg laying hormone ; Aplysia ; Binding protein ; Immunocytochemistry ; Reproductive system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract A protein solubilized from a membrane preparation of the gonad of Aplysia californica has been isolated by affinity chromatography, using bag cell egg-laying hormone (ELH) as the bound ligand, and partially purified and characterized by gel electrophoresis. The protein has an apparent molecular weight of 52 kDa and consists of two disulfide-linked subunits of about 30 kDa each. The protein is glycosylated and has an acidic pI. Approximately 10–15 μg of this protein can be isolated from a single ovotestis, representing less than 1% of the total protein in the gonad; but the protein could not be detected in buccal mass or body wall, tissues which do not have apparent response to ELH. Antibodies generated against this ELH-binding protein (ELHBP) were used to localize sites in the ovotestis which might contain this molecule and thus represent targets for egg-laying hormone. Immunocytochemical results indicate that the oocytes are a rich source of this protein, since their cytoplasm was the only detectable site of immunoreactivity. Whether this binding protein represents an egg-laying hormone receptor is uncertain, but its prevalence in oocytes suggests that ELH plays a signaling role on these gametes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00193520
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Immunocytochemical identification of androgen receptor in mouse osteoclast-like multinucleated cells (1994)
    Springer
    Calcified tissue international 54 (1994), S. 325-326 
    Details
    ISSN: 1432-0827
    Keywords: Androgen Receptor ; Osteoclast ; Mouse ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Expression of androgen receptor (AR) in mouse osteoclast-like multi-nucleated cells (OCs) was examined with immunocytochemical techniques. Murine OCs were obtained by co-culturing mouse osteoblastic cells and bone marrow cells. Three preparations of polyclonal anti-AR antibody which were raised in rabbit against different parts of the human AR were employed for the experiments. Specific staining for AR was demonstrated in the nuclei and the perinuclear area of mouse OCs. This is the first report demonstrating the presence of AR in osteoclast-like cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00295958
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Expression of growth hormone receptor by immunocytochemistry in rat molar root formation and alveolar bone remodeling (1992)
    Springer
    Calcified tissue international 50 (1992), S. 541-546 
    Details
    ISSN: 1432-0827
    Keywords: Growth hormone ; Growth hormone receptor ; Odontogenesis ; Bone remodeling ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Growth hormone (GH) may regulate tooth formation and bone remodeling associated with tooth eruption. This study reports the distribution of growth hormone receptor/binding protein in developing rat molars and adjacent alveolar bone by immunocytochemistry using well-characterized anti-growth hormone receptor monoclonal antibodies. These tissues represent an excellent model for studying the ontogenic changes that occur in odontogenic and osteogenic cells, as these cells are found in linear arrays displaying the various stages of morphological and functional differention, and differentiated function. Immunoreactivity was first seen in precementoblasts in contact with the epithelial root sheath, and preodontoblasts. However, growth hormone receptor immunoreactivity was associated primarily with the cytoplasm of odontogenic and osteogenic cells forming their respective matrices. Thus, cementoblasts and odontoblasts at sites of new matrix formation showed intense immunoreactivity whereas cementocytes and mature odontoblasts at later stages of tooth development were nonreactive. Osteoblasts engaged in intramembranous ossification in the alveolar bone were positive, although osteocytes and endosteal cells were immunonegative. Osteoclasts at sites of alveolar bone remodeling resorption were also immunopositive. These patterns of receptor expression parallel the ontogenic sequences of odontogenic and osteogenic cells and suggest that GH promotes the functional state of these cells. Our results also imply that GH may influence differentiation or differentiated functions associated with odontogenesis, osteogenesis, and bone remodeling independent of systemic insulin-like GF-I.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00582170
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    The egg-jelly macromolecule, a fucose sulphate glycoconjugate, originates from the accessory cells of the ovary in the sea urchin Hemicentrotus pulcherrimus (1992)
    Springer
    Development genes and evolution 201 (1992), S. 179-189 
    Details
    ISSN: 1432-041X
    Keywords: Sea urchin ; Jelly coat ; Accessory cell ; Oogenesis ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The immunocytochemical localization of the egg-jelly macromolecule, a fucose sulphate glycoconjugate (FSG) that induces the acrosome reaction in spermatozoa, was investigated in ovaries of the sea urchin Hemicentrotus pulcherrimus by use of a polyclonal antibody. The polyclonal antibody reacted with the accessory cells and oocytes in the ovarian lumen. In the accessory cells, evidence of an intense immunohistochemical reaction was observed in many globules of variable density. Products of the specific immunohistochemical reaction were frequently observed in the surface region of oocytes, at a distance from the ovarian wall. At the ultrastructural level, the polyclonal antibody was found to react with the material present in the vacuole-like structures of the globules in the accessory cells. Many gold particles, demonstrating specific immunolabelling, were associated with well-developed microvilli on the vitellogenic oocytes. In the mature oocytes, intense labelling was observed in the jelly coat but not in the vitelline coat. By contrast, oogonia and early oocytes were barely labelled. Quantitative data indicated that the extent of immunolabellings in the surface region of oocytes was very high in the vitellogenic and mature oocytes. In all cases, neither the oocyte cytoplasm nor the subcellular organelles were labelled. These results suggest that FSG is produced by the accessory cells and is deposited initially on the surface of vitellogenic oocytes for the formation of jelly. These findings may provide a new insight into the role of the accessory cells in the reproductive process of the sea urchin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00188717
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Seasonal variations in the production of the egg-jelly macromolecule, a fucose sulphate glycoconjugate, by the accessory cells in the ovary of the sea urchin Hemicentrotus pulcherrimus (1994)
    Springer
    Development genes and evolution 203 (1994), S. 402-410 
    Details
    ISSN: 1432-041X
    Keywords: Sea urchin ; Egg jelly ; Ovary ; Development ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In the sea urchin Hemicentrotus pulcherrimus, the egg-jelly macromolecule, a fucose sulphate glycoconjugate (FSG) that induces the acrosome reaction in spermatozoa, originates from the accessory cells in the ovary. In the present study we examined the seasonal variations in the distribution of FSG in the ovary by immunocytochemistry with a polyclonal antibody. An enzyme-linked immunosorbent assay indicated that FSG was present in supernatants of extracts of ovaries throughout the development of the ovary. However, the immunohistochemical study showed that there are marked seasonal changes in the distribution of FSG in ovaries. The polyclonal antibody reacted strongly with globules of accessory cells before the beginning of the breeding season (August to December). During the breeding season (February to April), the immunohistochemical reaction was found on the surface of oocytes but was weak in the accessory cells. At the ultrastructural level, the antibody reacted with globules of variable density in accessory cells. Intense immunolabelling was observed in the vacuole-like structures of the globules. Sometimes, products of the specific immunocytochemical reaction were found in the Golgi apparatus in these globules. Quantitative examination indicated that FSG was actively produced by the accessory cells from the late non-breeding season to the pre-breeding season. These results suggest that there are marked seasonal variations in the production of FSG by the accessory cells in the sea urchin ovary. These findings also provide new evidence that accessory cells exhibit dynamic changes during the reproductive process in the sea urchin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00188689
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Circadian photoreception in the retinally degenerate mouse (rd/rd) (1991)
    Springer
    Journal of comparative physiology 169 (1991), S. 39-50 
    Details
    ISSN: 1432-1351
    Keywords: Photoreception ; Retinally degenerate ; Mouse ; Circadian ; Rods ; Cones ; 11-cis retinaldehyde ; Immunocytochemistry ; HPLC
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary We have examined the effects of light on circadian locomotor rhythms in retinally degenerate mice (C57BL/6J mice homozygous for the rd allele: rd/rd). The sensitivity of circadian photoreception in these mice was determined by varying the irradiance of a 15 min light pulse (515 nm) given at circadian time 16 and meauring the magnitude of the phase shift of the locomotor rhythm. Experiments were performed on animals 80 days of age. Despite the loss of visual photoreceptors in the rd/rd retina, animals showed circadian responses to light that were indistinguishable from mice with normal retinas (rd/+ and +/+). While no photoreceptor outersegments were identified in the retina of rd/rd animals (80–100 days of age), we did identify a small number of perikarya that were immunoreactive for cone opsins, and even fewer cells that contained rod opsin. Using HPLC, we demonstrated the presence and photoisomerization of the rhodopsin chromophore 11-cis retinaldehyde. The rd/rd retinas contained about 2% of 11-cis retinaldehyde found in +/+ retinas. We have yet to determine whether the opsin immunoreactive perikarya or some other unidentified cell type mediate circadian light detection in the rd/rd retina.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00198171
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Periplasmic location of nitrous oxide reductase and its apoform in denitrifying Pseudomonas stutzeri (1992)
    Springer
    Archives of microbiology 157 (1992), S. 218-222 
    Details
    ISSN: 1432-072X
    Keywords: Denitrification ; N2O reductase ; Nitrite reductase ; Immunocytochemistry ; Localization ; Two-dimensional electrophoresis ; Cell fractionation ; Pseudomonas stutzeri
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Immunogold labelling techniques on ultrathin sections of low temperature embedded cells yielded evidence for the periplasmic location of the respiratory enzymes N2O reductase and nitrite reductase (cytochrome cd 1) in Pseudomonas stutzeri strain ZoBell. Cell fractionation by spheroplast preparation and two-dimensional electrophoresis showed the absence of a membrane association of these enzymes. Immunocytochemical localization of N2O reductase in a mutant strain deficient in the chromophore of N2O reductase showed the gold label at the cell periphery, indicating that the copper chromophore processing takes place after export of this protein's apoform.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00245153
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Contribution of nitrogen and phosphorus by precipitation in the drainage basin of the Santillana Reservoir (Madrid) (1994)
    Springer
    Environmental geology 23 (1994), S. 99-104 
    Details
    ISSN: 1432-0495
    Keywords: Nitrogen ; phosphorus ; Precipitation collector ; Nutrients rates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract The contribution of nitrogen and phosphorus due to precipitation constitutes the second most important route after superficial runoff. The sampling carried out during a two-year period by means of a precipitation collector allows us to determine the contribution of this route both qualitatively and quantitatively. Nitrogen is mainly supplied in an inorganic form, while phosphorus is principally supplied as orthophosphate. During the period of this study (March 1986–February 1988) it was found that in the Santillana Reservoir Watershed the level of nitrogen supplied by precipitation constitutes an average of 4.87% and the level of phosphorus constitutes 8.01%. The contribution of nitrogen varies in inverse ratio to precipitation and the contribution of phosphorus varies in direct ratio.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00766982
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Measurement of total dissolved phosphorus in small volumes of iron rich interstitial water (1992)
    Springer
    Aquatic sciences 54 (1992), S. 1-9 
    Details
    ISSN: 1420-9055
    Keywords: Sediment ; interstitial water ; phosphorus ; iron ; persulfate digestion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract It is shown that sorption of orthophosphate to iron compounds, formed during persulfate digestion, can cause a significant underestimation of total dissolved phosphorus in interstitial waters rich in iron and poor in phosphorus. Labelling the samples with carrier free32PO4 before digestion allows to correct for these losses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00877261
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    The ecosystem of a mesotrophic lake-II. Interactions among nutrient load, river flow, and epilimnion depth (1991)
    Springer
    Aquatic sciences 53 (1991), S. 263-272 
    Details
    ISSN: 1420-9055
    Keywords: Lake ecosystem ; chl-a ; phosphorus ; nitrogen ; river flow ; thermocline ; simulation model ; multiple regression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The management variables which primarily affect phytoplankton biomass (as chl-a) in Lake Mjøsa, Norway, are total phosphorus loading (TP) and the timing and volume of water through flow (by active storage reservoirs). The response of the lake to changes in these factors is studied using a simulation model of the lake ecosystem. Chl-a responses from both observed data and the simulated results are extracted by multiple regression. Results show that decreasing TP load decreases chl-a, but less at low TP levels (〈 10 mg TP · m−3). There is also a certain time period for peak river flow which gives the least yield of chl-a per unit TP. This time period occurs in early summer (i.e., around June 10) if the total phosphorus load is low, and later if the load is high. Both observations and simulation results show that a high water flow increases chl-a at low epilimnion depths (〈 15 m), but that the same high water flow decreases chl-a when epilmnion is deep.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00877062
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    The short term response to eutrophication abatement (1990)
    Springer
    Aquatic sciences 52 (1990), S. 199-220 
    Details
    ISSN: 1420-9055
    Keywords: Eutrophication ; lake management ; phosphorus ; ecosystem ; chlorophyll-a ; mathematical modelling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We compare results of a new model for predicting the short term inter annual changes in chlorophyll-a (chl-a) in lakes after reductions in total phosphorus (TP) to predictions made by least squares regression models. In the new method, slopes of chl-a/TP graphs (both axes in mg · m−3) are depicted in frequency diagrams and used to extract information on the expected, short term chl-a/TP response. The short term response for nine shallow (〈 10 m deep) and nutrient rich lakes to changes in TP was found to be: Chl-a = 0.49 · TP + 17.3, and for nine deep, P-limited lakes: Chl-a = 0.08 · TP + 3.5. If the TP-reduction is known to be greater than 10 mg · m−3, the expected slope increases to 0.58 for shallow lakes and to 0.26 for deep lakes. The slope, 0.58, is 8% lower than the slope for the long term response calculated by regression for the shallow lakes. For deep lakes the slope, 0.26, is 2 to 3 times higher than that calculated by regression, indicating that reductions in TP for deep lakes give greater effects than least squares regression equations suggest. We have also calculated the reduction in TP which will give about 80% probability that a reduction in chl-a will be observed next year. For shallow, P-limited lakes this reduction is about 30 mg · m−3 (5% of average initial in-lake TP concentration), and for deep lakes about 14 mg · m−3 (35% of average initial in-lake TP concentration).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00877280
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    Vertical mixing in Überlinger See, western part of Lake Constance (1990)
    Springer
    Aquatic sciences 52 (1990), S. 256-268 
    Details
    ISSN: 1420-9055
    Keywords: Vertical mixing ; stratification ; phosphorus ; Lake Constance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Depth variable vertical eddy diffusion coefficients for heat (K z) were calculated from continuously measured temperature profiles in Überlinger See (western part of Lake Constance). The temperatures were averaged over vertical intervals of 10 m yielding 14 discrete values (maximum depth of Überlinger See: 147 m). A linear fit from 10 June to 29 September 1987 was used to smooth the significant temperature fluctuations caused by internal seiches of Lake Constance. Assuming horizontal homogeneity for the smoothed data the Gradient-Flux-Method was applied to compute vertical diffusion coefficientsK z at different depths using the depth variable volumes and surfaces of the 14 layers. The resulting mean diffusion coefficients for the period from June to September are 0.04 cm2/s near the thermocline and up to 0.8 cm2/s in deeper strata (accuracy: ± 50%). It is shown that horizontal mixing between Überlinger See and Obersee (main lake) alters the computation ofK z by less than 50%. A relationship betweenK z and stability (Brunt-Väisälä) frequencyN is found which corresponds well to the theory of internal wave induced turbulence. Combining the diffusion coefficients with measured phosphorus profiles, a phosphorus flux from the hypolimnion to the epilimnion of (0.7 ± 0.4) mg P m−2 d−1 was calculated, corresponding to about 20% of the average external loading per area of Lake Constance in 1986.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00877283
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Nutrient-chlorophyll trajectories across trophic gradients (1992)
    Springer
    Aquatic sciences 54 (1992), S. 58-76 
    Details
    ISSN: 1420-9055
    Keywords: Eutrophication ; lake management ; phosphorus ; nitrogen ; chlorophyll-a ; slope estimator
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We estimate the response of chl-a (mg · m−3) to changes in concentrations of total phosphorus (TP) by calculating the slopeS = Δchl-a/ΔTP in chl-a =f(TP) graphs. Results show that in years where algae are P-limited oligotrophic lakes respond less (median slope 0.21) to changes in nutrient concentrations than eutrophic lakes, (median slope 0.31) and these again less than hypereutrophic lakes, (median slope 1.02). We find no saturation value for the slope within the TP range considered (6–480 mg · m−3). Chl-a in eutrophic lakes responds more frequently to non-nutrient factors than oligotrophic and hypereutrophic lakes. Results obtained by replacing TP with a new nutrient parameter, TP′ = 0.056 · TP · IN0.226, in which inorganic nitrogen, IN, is factored in, suggest that nitrogen has an influence on chl-a in oligotrophic lakes. Blue-green algae respond less to changes in TP than other algal species, e.g., diatoms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00877264
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Possibilities and limitations of lake restoration: Conclusions for Lake Lugano (1992)
    Springer
    Aquatic sciences 54 (1992), S. 381-390 
    Details
    ISSN: 1420-9055
    Keywords: Eutrophication ; phosphorus ; lake restoration ; internal restoration measures for lakes ; Swiss lakes ; Lake Lugano (Lago di Lugano)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In most lakes eutrophication is linked to an excessive input of phosphorus. Lake restoration by reduction of P-input (external measure) has led to a considerable drop of the P-concentration in all major Swiss lakes as well as in many other lakes. Internal restoration measures such as artificial mixing, drainage of hypolimnetic water, flushing, aeration, biomanipulation and others serve to improve and accelerate the response of a lake to external measures. For the case of Lago di Lugano, a simple two-box model is employed to demonstrate that a reduction of the P-input to about 25% of the present values is necessary to reach the “P-criterion” (P-concentration below 30 µg/l). Internal measures could possibly accelerate the extremely slow response of the northern basin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00878149
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    What controls levels of dissolved phosphate and ammonium in surface waters? (1993)
    Springer
    Aquatic sciences 55 (1993), S. 132-142 
    Details
    ISSN: 1420-9055
    Keywords: nitrogen ; phosphorus ; uptake ; regeneration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Dissolved inorganic nutrient pools are small relative to particulate pools, and dissolved pools turnover rapidly. It has been observed that pools change little from day to day on the sampling scales usually employed. A simple model is presented where uptake and regeneration rates balance to cause a local steady state concentration for dissolved inorganic nutrients. Enrichment and dilution perturbation experiments with lake water support the idea of steady state nutrient concentrations. Although inorganic nutrient concentrations are often controlled by biota, the absolute concentrations present tell little about the activity of that biota.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00877441
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Phosphorus and nitrogen limitation of algal biomass across trophic gradients (1994)
    Springer
    Aquatic sciences 56 (1994), S. 16-28 
    Details
    ISSN: 1420-9055
    Keywords: Chlorophyll-a ; phosphorus ; nitrogen ; lake ecosystem ; nutrient limitation ; regression analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Regression results based on data from 46 northern temperate lakes show that total phosphorus (TP) is the best predictor for phytoplankton (as chl-a) at lower trophic levels, TP 〈 200 mg · m−3. A regression including both TP and TN as regressors is the best predictor for lakes with TP 〉 200 mg · m−3. However, the good correlation is probably due to a high correlation between lake average chl-a (all years observed) and lake average TP and TN. Within single hypereutrophic lakes, TN alone is the best predictor. It was not possible to identify a medium trophic domain where TN and TP in combination was the best predictor for chl-a. The ratio TN:TP in the water decreases from about 40 to about 5 with increasing trophic level. Optimum TN:TP ratio for algal species with high abundance during late summer and autumn reflects this decreasing ratio, but within a lesser range, i.e., 20 to 5. In contrast, TN:TP ratios for species abundant during the early vernal period showed no, or an inverse, relation to the TN:TP ratio of the water.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00877432
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    Aboveground nitrogen and phosphorus use by five plantation-grown trees with different leaf longevities (1991)
    Springer
    Biodegradation 14 (1991), S. 167-191 
    Details
    ISSN: 1572-9729
    Keywords: leaf longevity ; nitrogen ; nutrient use efficiency ; phosphorus ; requirement ; retranslocation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Aboveground nitrogen (N) and phosphorus (P) requirement, retranslocation and use efficiency were determined for 28-year-old red oak (Quercus rubra L.), European larch (Larix decidua Miller), white pine (Pinus strobes L.), red pine (Pinus resinosa Ait.) and Norway spruce (Picea abies (L) Karst.) plantations on a similar soil in southwestern Wisconsin. Annual aboveground N and P requirements (kg/ha/yr) totaled 126 and 13 for red oak, 86 and 9 for European larch, 80 and 9 for white pine, 38 and 6 for red pine, and 81 and 13 for Norway spruce, respectively. Nitrogen and P retranslocation from current foliage ranged from 81 and 72%, respectively, for European larch, whereas red pine retranslocated the smallest amount of N (13%) and Norway spruce retranslocated the smallest amount of P (18%). In three evergreen species, uptake accounted for 72 to 74% of annual N requirement whereas for two deciduous species retranslocation accounted for 76 to 77% of the annual N requirement. Nitrogen and P use (ANPP/uptake) was more efficient in deciduous species than evergreen species. The results from this common garden experiment demonstrate that differences in N and P cycling among species may result from intrinsic characteristics (e.g. leaf longevity) rather than environmental conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00000806
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Effects of aflatoxin B1 on in vitro cultures ofNicotiana tabacum var. Samsun (1994)
    Springer
    Mycopathologia 125 (1994), S. 107-117 
    Details
    ISSN: 1573-0832
    Keywords: Aflatoxin B1 ; Immunocytochemistry ; Regeneration ; Tissue culture ; Tobacco plantlets
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The effects of aflatoxin B1, (0.5–25 µg ml−1) on in vitro root and shoot development in young tobacco explants were investigated. Despite an initial apparent stimulatory effect on most measured parameters at 0.5 µg ml−1 AFB1, the number of leaves, root and leaf mass per plantlet were progressively inhibited with increasing AFB1 concentration. The number of explants developing roots was reduced to 34% at the highest (25 µg ml−1) AFB1 concentration, following 3 weeks exposure to the toxin. Leaf chlorophyll content at this toxin concentration was significantly lower than that measured for control plantlets. Thin layer chromatography confirmed the absorption of AFB1 by the plantlets. Using immunocytochemical techniques, AFB1 was immunolocated predominantly in the vacuoles, the nucleus and the cytoplasm (possibly intravesicularly). The results are discussed in terms of this immunolocation within the cell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01371099
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    Historical changes in sediments of Pyramid Lake, Nevada, USA: consequences of changes in the water balance of a terminal desert lake (1994)
    Springer
    Journal of paleolimnology 12 (1994), S. 87-101 
    Details
    ISSN: 1573-0417
    Keywords: Great Basin ; climatic variations ; productivity ; organic matter ; nitrogen ; phosphorus ; hardwater lake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract Sediment cores from the shallow and deep basins of Pyramid Lake, Nevada, revealed variations in composition with depth reflecting changes in lake level, river inflow, and lake productivity. Recent sediments from the period of historical record indicate: (1) CaCO3 and organic content of sediment in the shallow basin decrease at lower lake level, (2) CaCO3 content of deep basin sediments increases when lake level decreases rapidly, and (3) the inorganic P content of sediments increases with decreasing lake volume. Variations in sediment composition also indicate several periods for which productivity in Pyramid Lake may have been elevated over the past 1000 years. Our data provide strong evidence for increased productivity during the first half of the 20th Century, although the typical pattern for cultural eutrophication was not observed. The organic content of sediments also suggests periods of increased productivity in the lake prior to the discovery and development of the region by white settlers. Indeed, a broad peak in organic fractions during the 1800's originates as an increase starting around 1600. However, periods of changing organic content of sediments also correspond to periods when inflow to the lake was probably at extremes (e.g. drought or flood) indicating that fluctuations in river inflow may be an important factor affecting sediment composition in Pyramid Lake.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00678089
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Bio-availability of iron from spinach (Spanicia oleracea) cultivated in soil fortified with graded levels of iron (1992)
    Springer
    Plant foods for human nutrition 42 (1992), S. 313-318 
    Details
    ISSN: 1573-9104
    Keywords: Iron availability ; phosphorus ; soil iron level ; ascorbic acid ; oxalic acid ; spinach
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In vitro availability of iron along with ascorbic acid, oxalic acid and phosphorus content of two varieties of spinach (Pusa Jyoti and Allgreen) cultivated in soil with different levels of added iron was determined. Addition of graded levels of iron to soil markedly increased the total iron and phosphorus contents and significantly decreased the bio-availability of iron, ascorbic acid and oxalic acid contents of spinach. Ascorbic acid and oxalic acid contents markedly exerted a positive influence while phosphorus exerted a negative influence on the bio-availability of iron.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02194092
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    Determination of orthophosphate in highly saline waters (1994)
    Springer
    International journal of salt lake research 3 (1994), S. 159-173 
    Details
    ISSN: 1573-8590
    Keywords: phosphorus ; orthophosphate ; phosphomolybdenum blue ; salt effect ; hypersaline ; saline ; lakes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract Standard methods for the determination of phosphorus as phosphate ion are now well established for fresh and marine waters. In highly saline waters, however, salt effects due to ionic strength, or to particular ions present, may result in method interferences. Three methods of analysis of phosphate based on the formation of phosphomolybdenum blue complexes have been evaluated here for hypersaline waters. Stannous chloride reduction in aqueous media exhibits a substantial salt effect and its use is not recommended. Stannous chloride reduction following extraction into non aqueous solvents shows a significant salt effect (up to 30 per cent) in solutions of salinity 〉100 g L−1. Dilution of hypersaline waters to below this salinity may overcome the salt effect but the method suffers from other disadvantages involving resource constraints and health and safety considerations. Ascorbic acid reduction, catalysed by antimony (III) ions, appears to offer the most promise for hypersaline waters. Turbidity in samples having high salinity (〉 100 g L−1) and high phosphorus concentrations (〉 500 μg P L−1) changes the spectral characteristics of solutions but linear calibration curves still result for concentrations in the range 400 to 1,000 μg P L−1. The occurrence of turbidity is also affected by the ionic composition of hypersaline waters since solutions made from sea salt give different results to those made from sodium chloride. Dilution of samples, to give salinities less than 100 g L−1 prior to reduction is recommended to avoid turbidity. The salt effect in these lower salinity waters is less than 3 per cent up to 100 g L−1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01990492
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Nutrient and hydrologic budgets of a great lakes coastal freshwater wetland during a drought year (1992)
    Springer
    Wetlands ecology and management 1 (1992), S. 211-222 
    Details
    ISSN: 1572-9834
    Keywords: freshwater marsh ; freshwater wetland ; Great Lakes ; hydrology ; phosphorus ; water quality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A coastal wetland along Lake Erie (Ohio, U.S.A.) was studied to determine hydrologic and phosphorus budgets and spatial and temporal variation of phosphorus and related chemical parameters. The wetland was influenced by changing Lake Erie water levels, seiches, shifting shoreline sediments, and watershed inflow during a year of severe drought. The water budget for a 7-month period (March – September, 1988) had average inflow of 15 200 m3 day−1 from the watershed and 3.5 m3 day−1 from Lake Erie. The wetland increased in volume by 700 m3 day−1 despite a drought that resulted in 80% more evapotranspiration than rainfall as a barrier beach isolated the wetland from Lake Erie for 77% of the study period. Conductivity decreased by 34% as water flowed through the wetland and turbidity and total suspended solids were variable and statistically similar at inflow and outflow. Average total phosphorus concentrations in the inflow and outflow were also similar (247 and 248 µg P l−1 respectively) although total soluble phosphorus and soluble reactive phosphorus decreased significantly (α=0.05) from inflow to outflow (averages 94 to 45 µg P l−1 and 7.5 to 4.0 µg P l−1 respectively). Nutrient budgets from field data estimate a retention of 36% of the phosphorus, presumably in the sediments (0.8 mg P m−2 day−1). A general nutrient retention model, an estimated deposition rate from a sediment core and a simulation model predicted higher mass retention of phosphorus but similar percentage retention. Sommaire Un marecage qui côtoie le lac Erie (USA) a servi de site expérimental pour en déterminer les budgets d'eau et de phosphore, de même que pour la variation spatiale et temporelle du phosphore et d'autres facteurs chimiques. Le marécage a été influencé par: niveaux d'eau qui changeaient; seiches; sédiments mouvants du littoral; et afflux de la ligne de partage des eaux dans une année de grande sécheresse. Le budget d'eau dans une période de 7 mois (mars–septembre 1988) montre un afflux de 15 200 m3 jour−1 de la ligne de partage, et 3.5 m3 jour−1 du lac Erie. Le volume du marécage a augmenté par 700 m3 jour−1 malgré une sécheresse qui a produit plus d'évapotranspiration (80%) que de pluie pendant qu'une plage-obstacle a isolé le marecage du lac Erie pendant 77% de la période d'observation. La conductivité a diminué par 34% pendant que l'eau coulait, et la turbidité et les TSS ont varié, tout en démontrant des statistiques similaires à l'afflux et au déversement. Les moyennes pour les concentrations du total du phosphore à l'afflux et au déversement ont été similaires (247 and 248 µg P l−1), quoique le TSP et le SRP ont diminué (α=0.05) de l'afflux au déversement (donant des moyennes de 94 à 45 µg P l−1 et de 7.5 à 4.0 µg P l'−1). Les budgets de substances nutritives pour les données suggèrent une reténtion de 36% du phosphore, évidemment dans les sédiments (0.8 mg P m−2 jour−1). Un modèle pour la rétention des nutrients, un taux de déposition, estimé par un noyau de sédiments, et une simulation avaient prédit un plus grand taux de rétention de phosphore, mais un pourcentage similaire pour la rétention.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00244926
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    Rhizome dynamics and resource storage in Phragmites australis (1992)
    Springer
    Wetlands ecology and management 1 (1992), S. 239-247 
    Details
    ISSN: 1572-9834
    Keywords: biomass ; carbohydrates ; nitrogen ; phosphorus ; Phragmites australis ; potassium ; reed ; rhizome ; translocation ; wetland
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Seasonal changes in rhizome concentrations of total nonstructural carbohydrates (TNC), water soluble carbohydrates (WSC), and mineral nutrients (N, P and K) were monitored in two Phragmites australis stands in southern Sweden. Rhizome biomass, rhizome length per unit ground area, and specific weight (weight/ length ratio) of the rhizomes were monitored in one of the stands. Rhizome biomass decreased during spring, increased during summer and decreased during winter. However, changes in spring and summer were small (〈 500 g DW m-2) compared to the mean rhizome biomass (approximately 3000 g DW m−2). Winter losses were larger, approximately 1000 g DW m-2, and to a substantial extent involved structural biomass, indicating rhizome mortality. Seasonal changes in rhizome length per unit ground area revealed a rhizome mortality of about 30% during the winter period, and also indicated that an intensive period of formation of new rhizomes occurred in June. Rhizome concentrations of TNC and WSC decreased during the spring, when carbohydrates were translocated to support shoot growth. However, rhizome standing stock of TNC remained large (〉 1000 g m−2). Concentrations and standing stocks of mineral nutrients decreased during spring/ early summer and increased during summer/ fall. Only N, however, showed a pattern consistent with a spring depletion caused by translocation to shoots. This pattern indicates sufficient root uptake of P and K to support spring growth, and supports other evidence that N is generally the limiting mineral nutrient for Phragmites. The biomass data, as well as increased rhizome specific weight and TNC concentrations, clearly suggests that “reloading” of rhizomes with energy reserves starts in June, not towards the end of the growing season as has been suggested previously. This resource allocation strategy of Phragmites has consequences for vegetation management. Our data indicate that carbohydrate reserves are much larger than needed to support spring growth. We propose that large stores are needed to ensure establishment of spring shoots when deep water or stochastic environmental events, such as high rhizome mortality in winter or loss of spring shoots due to late season frost, increase the demand for reserves.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00244929
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    How do non-differentiating bacteria adapt to starvation? (1993)
    Springer
    Antonie van Leeuwenhoek 63 (1993), S. 333-341 
    Details
    ISSN: 1572-9699
    Keywords: survival ; starvation ; stress ; Vibrio ; carbon ; nitrogen ; phosphorus ; protein synthesis ; carbon starvation stimulon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Non-differentiating bacteria adapt to starvation induced growth arrest by a complex turn-on/turn-off pattern of protein synthesis. This response shows distinct similarities with those of spore formation in differentiating organisms. A substantial amount of information on the non-growth biology of non-differentiating bacteria can be derived from studies onVibrio strains. One important result is that carbon rather than nitrogen or phosphorus starvation leads to the development of a starvation and stress resistant cell in these organisms. Hence, we have attempted to characterize the carbon starvation stimulon. By the use of two-dimensional gel electrophoresis of pulse-labelled cells and transposon mutagenesis, using reporter gene constructs, the identity and function of some members of the carbon starvation stimulon have been elucidated. Moreover, regulatory genes of the starvation response have been identified with these techniques. Current studies primarily address the identity and function of these genes. The role of transcript modification and stability for both long term persistence during starvation as well as the efficient recovery of cells which occurs upon nutrient addition is also addressed. It is suggested that an understanding of the functionality of the translational machinery is essential for the understanding of these adaptive pathways. This contribution also discusses the diversity of the differentiation-like response to starvation in different bacteria and whether a general starvation induced programme exists.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00871228
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    Mycorrhizal dependency of micropropagated argan tree (Argania spinosa): II. Mineral nutrition (1994)
    Springer
    Agroforestry systems 27 (1994), S. 67-77 
    Details
    ISSN: 1572-9680
    Keywords: Argania spinosa ; micro-elements ; nitrogen ; phosphorus ; V.A. mycorrhization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Description / Table of Contents: Résumé L'influence de la mycorhization V.A. sur la nutrition minérale de 2 clones d'Arganier (Argania spinosa) a été étudiée sur des plantules micropropagées in vitro poussant en conditions contrôlées. L'inoculation (qui augmentait la production de matière sèche d'un facteur 4,5) accroit également la teneur des plantes en phosphore, notamment dans les feuilles, et les plantes mycorhizées mobilisent 15 fois plus de phosphore que les plantes non inoculées. La teneur en azote est légèrement plus faible chez les plantes mycorhizées mais au total ces dernières exportent 3 fois plus d'azote. L'absorption des micro-éléments est aussi affectée par l'inoculation, qui accroit les teneurs des plantes en Fe, Zn et Cu. La nutrition minérale des deux clones étudiés semble affectée par le rapport racines/parties aériennes et d'autres caractéristiques génétiques, comme l'efficacité de translocation du fer. Ces résultats nous permettent de comprendre en quoi son système racinaire profond et mycorhizé permet à l'Arganier non seulement de pousser dans des zones arides aux sols pauvres, mais aussi d'améliorer la fertilité des couches supérieures du sol par l'effet litière.
    Notes: Abstract The influence of V.A. mycorrhization on mineral nutrition of 2 clones ofArgania spinosa was studied with in-vitro micropropagated plantlets grown in confined medium under controlled conditions. Inoculation, which increased dry matter production by a factor of 4.5, also increased P concentration in the plant, especially in the leaves, and the mycorrhizal plants mobilized 15 times more P than control plants. N concentration was slightly lower in mycorrhizal plants, but total N content was 3 times higher. Uptake of micro elements was also affected, inoculation increasing plant Fe, Zn and Cu content. Mineral nutrition in the test clones seemed affected by root/shoot ratio and other genetically-related characteristics, such as Fe translocation efficiency. These results help us to understand how its deep mycorrhizal root system might allowArgania spinosa not only to grow in infertile arid areas but also to improve top-soil fertility by a litter effect.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00704835
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    Effects of ferulic acid, an allelopathic compound, on net P, K, and water uptake by cucumber seedlings in a split-root system (1990)
    Springer
    Journal of chemical ecology 16 (1990), S. 2429-2439 
    Details
    ISSN: 1573-1561
    Keywords: Cucumis sativus ; ferulic acid ; split root ; phosphorus ; potassium ; water ; net uptake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Since distribution of allelopathic compounds in soils is highly variable, injurious effects by such compounds should be related to the frequency of contact with roots. Experiments were conducted to determine how P, K, and water uptake of cucumber seedlings were affected as the fraction of roots in contact with ferulic acid (FA) was increased. Seedlings were grown in Hoagland's nutrient solution for 14 days and then transferred to 0.5 mM CaSO4 solution for 24 hr before being placed into a split-root culture system. The containers in the system were filled with 0.5 mM concentrations of KH2PO4 and CaSO4 or 0.5 mM concentrations of KH2PO4, CaSO4, and ferulic acid (FA). Net uptake of P by seedlings (milligrams per seedling) decreased in a curvilinear (concave) manner as the fraction of the roots in contact with FA increased. Net uptake of K (milligrams per seedling) and water (milliliters per seedling) by seedlings decreased linearly as the fraction of the roots in contact with FA increased. Net uptake of P, K, and water by seedlings was reduced 57, 75, and 29%, respectively, when the whole root system was exposed to FA. Net P and K uptake of roots (milligrams per gram root fresh weight) not in contact with FA decreased in a linear and curvilinear (convex) manner, respectively, as the fraction of roots in contact with FA increased. Net P and K uptake of roots in contact with ferulic acid increased in a linear and curvilinear (convex) manner, respectively. Net water uptake of roots (milliliters per gram root fresh weight) not in contact with FA increased in a curvilinear (concave) manner as the frequency of the roots in contact with FA increased. Net water uptake of roots in contact with FA did not show a trend. Transpiration (milliliters per square centimeter) was reduced in a linear manner as the fraction of roots in contact with FA increased. A very slight compensation by roots not in contact with FA for roots in contact with FA was observed for net water uptake rates. No compensation for P and K uptake rates was observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01017466
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    Inhibition ofSchizachyrium scoparium (poaceae) by the allelochemical hydrocinnamic acid (1992)
    Springer
    Journal of chemical ecology 18 (1992), S. 2095-2105 
    Details
    ISSN: 1573-1561
    Keywords: Allelopathy ; Schizachyrium scoparium ; Ceratiola ericoides ; hydrocinnamic acid ; nitrogen ; phosphorus ; potassium ; fire ; sand pine scrub ; sandhill
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Bare zones around shrubs in the Florida scrub indicate the possibility of allelopathy by shrubs controlling the distribution of grasses invading from adjacent sandhills. The allelochemical, hydrocinnamic acid, has been identified as a breakdown product of ceratiolin, which is released from the shrubCeratiola ericoides. Here, hydrocinnamic acid (HCA) was shown to have a strongly inhibitory effect on shoot and root biomass of the grassSchizachyrium scoparium in greenhouse bioassays lasting 4.5 months. Linear increases in the concentration of HCA from 0 to 200 ppm, applied biweekly, resulted in exponential decreases in root and shoot biomass at harvest. Plants grown at 200 ppm HCA had root and shoot biomasses 13% and 17% of controls, respectively. Concurrent investigation of reduced nutrient levels indicated greater inhibition by HCA in a reduced nitrogen (N) treatment and in a reduced potassium (K) treatment relative to HCA inhibition in the full nutrient treatment. The negative slopes of the regressions of log of biomass on HCA concentration were steepest in the reduced N and reduced K treatments. Root and shoot biomasses in reduced N treatments were 20–43% and 24–34% less than the respective biomasses in the full nutrient treatment. Comparable reductions in the reduced K treatment were as much as 19% and 10% for root and shoot biomasses, respectively. The effects of HCA in a reduced phosphorus (P) treatment and in a reduced P and K treatment were not significantly different from the effects of HCA in the full nutrient treatment. Extraction of the soils at harvest indicated no buildup of HCA at the end of the experiment. The sensitivity ofSchizachyrium scoparium to HCA in general and increased sensitivity under low N and low K solutions may be important in the Florida scrub community where levels of N and K are known to be low.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00981930
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    Bark consumption by voles in relation to mineral contents (1991)
    Springer
    Journal of chemical ecology 17 (1991), S. 735-743 
    Details
    ISSN: 1573-1561
    Keywords: Sodium ; calcium ; phosphorus ; vole ; Microtus agrestis ; bark consumption ; field experiments
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Recent field experiments with impregnated wooden sticks have demonstrated a pronounced use by small rodents of mineral supplies, especially sodium, and such findings seemed related to vole damage to forestry seedlings. Consumption of the bark of experimentally introduced aspen twigs and of sodium-impregnated sticks by voles (mainly or onlyMicrotus agrestis) correlated significantly on clear-cuts but not on unmanipulated abandoned fields. Such a correlation appeared when abandoned fields were cut continuously in summer. At vole peak densities, bark of pine seedlings experimentally fertilized with sodium was consumed but not bark of seedlings fertilized with calcium or control seedlings. Field pine seedlings attacked by voles had significantly higher levels of calcium, sodium, and phosphorus than the nearest untouched seedling. However, sodium and phosphorus contents correlated strongly. Sodium and calcium supply to voles in laboratory feeding trials did not diminish the moderate interest in pine bark. Such conditions are, however, assumed to mimic a situation of bark sampling in low-density populations. Sodium, and possibly also calcium, requirements are concluded to be partial determinants of the destructive bark consumption by voles at the peaks of their multiannual population cycles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00994196
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    The roles of nitrogen, phosphorus and Potassium in the production of sugarcane in South Africa (1990)
    Springer
    Nutrient cycling in agroecosystems 26 (1990), S. 89-98 
    Details
    ISSN: 1573-0867
    Keywords: Nitrogen ; phosphorus ; potassium ; sugarcane ; fertilizer use
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The amounts of N and K fertilizers used in the South African sugar industry have increased dramatically in the past four decades, due partly to an increase in the area under sugarcane but also to large increases in the amounts of N and K fertilizers applied per hectare. There has also been an increase in the amount of P fertilizer used but this has been more gradual. The main fertilizer carriers for cane and their relative efficiency are discussed. During this period there has been considerable research into the nutrient requirements of sugarcane. Correlations established between soil and leaf analysis and crop responses to N, P and K fertilizers, and their effects on cane quality, are reviewed. While fertilizer recommendations based on soil and leaf analysis have provided a useful guide for determining the nutrient requirements of cane, they are continually being modified in the light of current research.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01048746
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    Liming, nitrogen and phosphorus fertilization and the annual volume increment of Norway spruce stands on long-term permanent plots in Southwestern Germany (1991)
    Springer
    Nutrient cycling in agroecosystems 27 (1991), S. 87-93 
    Details
    ISSN: 1573-0867
    Keywords: Volume increment ; Norway spruce ; liming ; nitrogen ; phosphorus ; fertilization ; precipitation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The amount, fluctuation and duration of increment response to fertilization (liming) in three regions of southwestern Germany is described. After liming, additional yield increases slowly while after N-fertilization, there is a rapid yield increase. A long-lasting high response was found to a combination of liming, P- and N-fertilization. This response was regionally different and was influenced by climatic conditions during the years after fertilization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01048611
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    The influence of tillage and cropping-intensity on cereal response to nitrogen, sulfur, and phosphorus (1992)
    Springer
    Nutrient cycling in agroecosystems 31 (1992), S. 15-19 
    Details
    ISSN: 1573-0867
    Keywords: Tillage ; crop rotation ; cereal grain ; wheat ; nitrogen ; sulfur ; phosphorus ; no-till
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Efficient fertilizer use is a prerequisite for achieving optimum crop yield while avoiding environmental contamination. Cereal response to nitrogen (N), sulfur (S), and phosphorus (P) were determined for 6 years under differing tillage [conventional-till (CT) vs. no-till (NT)] and intensity of cropping (cereal/fallow vs. cereal/cereal). Semidwarf white winter wheat (Triticum aestivum L.) alternated yearly with either fallow or spring cereal [barley (Hordeum vulgare L.) or spring wheat] on a Typic Haploxeroll soil in a 415 mm rainfall zone. Fertilizer treatments were no fertilizer (None), N only (N), N plus S (NS), and N plus S plus P (NSP). Average application rate, when applied, was 109 kg N, 18 kg S, and 11 kg P ha−1. Average cereal yield without fertilizer was 1.82 t ha−1. Nitrogen increased grain yield in 6 of 6, S in 4 of 6, and P in 3 of 6 years, with P and S response significant the remaining years at the 10% probability level. Average yield increases were 1.11 t ha−1 for N, 0.93 t ha−1 for S, and 0.47 t ha−1 for P. The NT/CT yield ratio was 0.60, 0.75, 0.93, and 0.95 with None, N, NS, and NSP addition, respectively, indicating that N and S deficiency were more severe in no-till. Limited increase in the NT/CT ratio with P addition indicated that P deficiency was less affected by tillage. Winter wheat always yielded less under NT than CT regardless of fertility, whereas spring cereals reached equality when fertilized with NSP. Annually-cropped wheat yielded 52, 67, 89, and 90% of wheat after fallow with None, N, NS, and NSP, respectively. Thus N and S, but not P, deficiency was more intense with increased frequency of cropping. Adequate fertility was a prime prerequisite for efficient yield in all systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01064223
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    Response of ensete (Ensete ventricosum W.) to mineral fertilizers in southwest Ethiopia (1994)
    Springer
    Nutrient cycling in agroecosystems 37 (1994), S. 107-113 
    Details
    ISSN: 1573-0867
    Keywords: Ensete ventricosum ; fertilizer response ; nitrogen ; phosphorus ; potassium ; sulphur ; starch
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Ensete (Ensete ventricosum W. Cheesm.) is a root crop which stores starch in the root and in the lower part of the stem. It is grown in the southwest of Ethiopia and due to its drought resistance, it is of outstanding importance for the supply of food to the local population. Until now virtually nothing is known about the response of Ensete to fertilizer application. Field trials carried out on three representative soils in Ethiopia showed that Ensete biomass yields were increased significantly on all three soils by nitrogen and phosphorus application. Potassium had only marginal effect on biomass growth but favourably influenced starch production. Sulfate application had no major impact on growth and starch yield. The yield response was well related to the level of available nutrients in the soil, as determined by electroultrafiltration (EUF). Leaf analysis provided preliminary evidence that optimum levels of N, P, and K may be 3.8%, 0.3%, and 4.8%, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00748551
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    Fertilization of millet cv. Souna III in Senegal: dry matter production and nutrient uptake (1993)
    Springer
    Nutrient cycling in agroecosystems 35 (1993), S. 217-226 
    Details
    ISSN: 1573-0867
    Keywords: calcium ; dry matter distribution ; fertilizer ; harvest index ; magnesium ; manure ; millet ; nitrogen ; nutrient uptake ; phosphorus ; potassium ; Senegal
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In a fertilizer and manure experiment, millet was grown under four treatments (no fertilizer or manure, farmyard manure, chemical fertilizer, and both). Grain yield and total aboveground biomass production of the unfertilized plot were relatively high. The observed differences in total dry matter production must be attributed to differences in nutrient availability, as amount of rainfall and its distribution were favourable. Results show only small differences in distribution of dry matter among the various plant organs between the best and the non-fertilized treatments. Nutrient supply from natural sources, defined as crop content of N, P, and K at maturity without fertilizer application, amounted to 104, 16 and 103 kg ha−1, respectively, which are very high values. Total uptake of calcium and magnesium is related to that of potassium, as the combined content of these three elements is linearly related to total aboveground biomass production. Minimum removal of nitrogen and phosphorus per ton grain dry matter amounts to 29 and 4kg, respectively, and 9 kg potassium per ton total aboveground dry matter. A possible double function of phosphorus as element of structural biomass and for maintenance of electro-neutrality is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00750640
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    Soil nutrient depletion by agricultural production in Southern Mali (1993)
    Springer
    Nutrient cycling in agroecosystems 36 (1993), S. 79-90 
    Details
    ISSN: 1573-0867
    Keywords: agriculture ; Sahel ; Sudan ; Mali ; cotton ; fertilization ; nutrient ; soil ; soil degradation ; depletion ; nutrient ; nutrient balance ; nitrogen ; phosphorus ; potassium ; calcium ; magnesium ; acidification ; sustainability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The degree of soil mining by agricultural production in Southern Mali is assessed by calculating nutrient balances: differences between the amount of plant nutrients exported from the cultivated fields, and those added to the fields. Export processes include extraction by crops, losses due to leaching, to erosion, and to volatilization and denitrification. Inputs include applications of fertilizer and manure, restitution of crop residues, nitrogen fixation, atmospheric deposition of nutrients in rain and dust, and enrichment by weathering of soil minerals. Nutrient balances are calculated for N, P, K, Ca, and Mg. Both pessimistic and optimistic estimates are given. The resulting figures indicate, even when the most optimistic estimates are used, large deficits for nitrogen, potassium and magnesium. For the region as a whole, the calculated deficits are -25 kg N/ha,-20 kg K/ha, and -5 kg Mg/ha. Further, acidification is to be expected, in particular in areas where cotton is grown. The deficits are caused by traditional cereal crops, but also by cotton and especially by groundnut. The latter two crops are fertilized, but insufficiently. It is important to note, that the negative figures are not automatic recommendations for application of a specific amount of additional fertilizer. For phosphorus and calcium the balance of the region as a whole appears to be about in equilibrium, but locally large variations may occur. Erosion and denitrification are important causes of nutrient loss, accounting respectively for 17 and 22% of total nitrogen exports. Atmospheric deposition and weathering of minerals in the soil are still important nutrient inputs that contribute as much as nutrients as organic and mineral fertilizer combined. Nutrient depletion is very large in comparison to the amount of fertilizer applied. Drastic options, such as doubling the application of fertilizer or manure, or halving erosion losses, even if feasible, would still not be enough to make up for the calculated deficits. The annual value of withdrawn nutrients, if related to prices of fertilizers, varies between 10,000 and 15,000 FCFA/ha (40-60 US $/ha). Since the estimated average gross margin from farming in this area is 34,000 FCFA/ha (123 US $/ha), soil mining appears to provide an amount equal to 40% of farmers' total income from agricultural activities.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00749951
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    Eutrophic waters of southwestern Australia (1993)
    Springer
    Nutrient cycling in agroecosystems 36 (1993), S. 105-114 
    Details
    ISSN: 1573-0867
    Keywords: eutrophication ; phosphorus ; algae ; cyanobacteria ; seagrasses ; plankton ; benthic fauna
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Water bodies in coastal areas of southwestern Australia are predisposed to eutrophication. The sandy soils of the catchments retain nutrients poorly, streamflow is highly seasonal, most freshwater wetlands are small and shallow, and the estuaries are poorly flushed. Nearshore waters lack the conventional upwelling of other coastal regions in these latitudes. Consequences include increased macroalgal growth and phytoplankton blooms, especially of cyanobacteria, and loss of seagrasses. Changes to fish and invertebrate populations result both from increased algal production and low oxygen concentrations. Algal toxins and outbreaks of botulism have caused waterbird casualties. Phosphorus is especially important in controlling plant biomass in freshwater wetlands and estuaries, and N in some wetlands and coastal embayments. In the examples reviewed here nutrients are derived mainly from fertilizer applications in catchments and rural industries, and from sewage and individual discharges to coastal waters.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00747580
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    Fertilizers and eutrophication in southwestern Australia: Setting the scene (1993)
    Springer
    Nutrient cycling in agroecosystems 36 (1993), S. 95-103 
    Details
    ISSN: 1573-0867
    Keywords: eutrophication ; phosphorus ; fertilizer ; Peel-Harvey estuary ; algal blooms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract An excess of plant nutrients has caused serious eutrophication in aquatic ecosystems of southwestern Australia manifested by excessive growth and accumulation of green and bluegreen algae. Phosphorus is generally the limiting nutrient for algal growth and phosphatic fertilizers applied to nutrient-deficient, leaching, sandy soils are the main source of P, supplemented by rural industry point sources. Nitrogen is the limiting nutrient in marine embayments with little drainage from the land. Measures to reduce the load of P delivered to drainage include basing fertilizer application rates on soil testing for P and the use of less soluble P fertilizers. Catchment management plans are being implemented with community involvement to reduce P loads and maintain agricultural production. This introductory paper reviews the history of eutrophication in southwestern Australia and of studies into its causes, principally in the large Peel-Harvey estuary. It briefly summarises other papers in this special issue concerned with different aspects of the problem: how to fertilize the land without causing eutrophication.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00747579
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    Phosphorus retention and release from sandy soils of the Peel-Harvey catchment (1993)
    Springer
    Nutrient cycling in agroecosystems 36 (1993), S. 115-122 
    Details
    ISSN: 1573-0867
    Keywords: phosphorus ; retention ; release ; sandy soils
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In order to manage phosphorus (P) losses from soils to waterbodies, knowledge of the mechanisms through which P is retained or released from the soil is essential. Sandy soils of the Peel-Harvey catchment (Western Australia) were subjected to a range of environmental and management factors in the laboratory and field in order to gain an understanding of the mechanisms that affect the magnitude of P losses. Sandy soils accumulated P, despite having little sorption capacity, and this accumulation could be monitored by measuring an acid-extractable fraction. The potential, short-term P loss could be estimated by determination of water-soluble soil solution P prior to winter rains. An annual cycle of the change in arbitrarily defined soil-P pools is discussed in relation to environmental and management factors. Laboratory experiments indicated that P rundown and potential annual P loss in the absence of P fertilizers could be estimated using bicarbonate extractable P. Phosphorus losses were decreased by the application of fertilizers with a low content of water-soluble P. The low ability of sandy soils of the Peel-Harvey coastal catchment to retain P, when compared to other Western Australian soils, is because of low contents of clay minerals and iron and aluminium hydrous oxides.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00747581
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    Hydrology of the Peel-Harvey estuary catchment (1993)
    Springer
    Nutrient cycling in agroecosystems 36 (1993), S. 127-133 
    Details
    ISSN: 1573-0867
    Keywords: hydrology ; water balance ; phosphorus ; Streamflow ; Peel-Harvey
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract This paper discusses the land types, hydrologic characteristics and processes, and the major modification of these, in relation to mechanisms and magnitude of phosphorus losses to drains and riverine systems which discharge to the Peel-Harvey estuary. About 75% of the coastal plain part of the catchment is cleared of native vegetation and used for dryland, dairy and beef grazing. There are small areas devoted to irrigated pasture and commercial horticulture. Seventy-five percent of the soils of the catchment are sandy surfaced with a poor capacity to retain phosphorus. Though the area is flat, catchment water yields are high because of a large winter rainfall excess and low soil storage capacity. Drainage schemes have been constructed in much of the catchment to remove excess water quickly. This was required initially to allow agricultural expansion and is now important for protecting a growing infrastructure which serves the most populous region of Western Australia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00747583
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    The potential use of wetlands to reduce phosphorus export from agricultural catchments (1993)
    Springer
    Nutrient cycling in agroecosystems 36 (1993), S. 157-164 
    Details
    ISSN: 1573-0867
    Keywords: phosphorus ; wetlands ; nutrient uptake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Natural and artificial wetlands have the potential to reduce phosphorus (P) loads from dispersed agricultural runoff and from point sources in the Peel-Harvey catchment, Western Australia. Small experimental systems containing wetland plants and substrate have shown significant removal of P from inflowing water, the proportion of P removed being dependent on P concentration and flow rate of water through the system. The use of artificial wetlands to treat diffuse agricultural runoff is limited by the highly seasonal runoff typical of this Mediterranean climate, while use at point sources has so far been unsuccessful because compounds from the effluent clog the wetland ‘filters’. Treatment at point sources may well be feasible after further research. Natural wetlands in the catchment absorb P received in runoff from farmland and, in the absence of any outflow channels to the drainage system, confine this P within the boundaries of the wetland. Disturbance to wetlands may reduce their efficiency in absorbing nutrients and may release P stored in the vegetation and sediment to the water. The conservation of natural wetlands is recommended to maximise nutrient retention in the catchment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00747587
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    Managing nutrient losses from rural point sources and urban environments (1993)
    Springer
    Nutrient cycling in agroecosystems 36 (1993), S. 165-170 
    Details
    ISSN: 1573-0867
    Keywords: phosphorus ; nutrient loss ; management ; point sources
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Nutrient loss from rural point sources and urban environments need to be minimised as part of strategies to overcome declining water quality on the Swan Coastal Plain and in the Peel-Harvey estuary in Western Australia. This paper discusses the management of nutrient losses from domestic effluent, urban stormwater runoff, domestic gardens and public open space, intensive animal industries and intensive irrigated agriculture. Measures to minimise nutrient losses from these sources are outlined, using cooperative, technological and regulatory approaches.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00747588
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    Environmental impact of fertilizing soils by using sewage and animal wastes (1994)
    Springer
    Nutrient cycling in agroecosystems 37 (1994), S. 1-22 
    Details
    ISSN: 1573-0867
    Keywords: animal slurries and manures ; applications to soils ; carbon- ; nitrogen- ; phosphorus ; contamination ; crop production ; dissemination ; hazardous organics ; heavy metals ; inputs ; macro- and micronutrients ; pathogens ; sewage sludges ; survival- ; transfer- ; transport and adsorption rates in soils
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The European Community is producing annually about 300 × 106 tons of sewage sludges as well as about 150, 950,160 and 200 tons of domestic, agricultural, industrial and other wastes (street litter, dead leaves etc.). About 20–25% of the German sewage sludges, which contain in average about 3.8,1.6, 0.4, 0.6, 5.3% DM−1 N, P, K, Mg and Ca, 202, 5, 131, 349, 53, 3 and 1446 mg kg−1 DM Pb, Cd, Cr, Cu, Ni, Hg, Zn as well as ca. 37 and 5 mg kg−1 Dm polychlorinated hydrocarbons and biphenyls, are recycled annually as fertilizer. In addition environmental impacts on the arable land of Germany may derive from 76,19.2, 64.7, 33.6, 7.8 and 0.1 kg ha−1 a−1 of N, P, K, Ca, Mg and Cu added as animal manures. Besides heavy metals and hazardous organics pathogens are disseminated with organic wastes. Crop production and soil fertility generally profit from the considerable amounts of plant nutrients and carbon in sewage sludges, animal slurries and manures, but the physicochemical soil properties, the composition of microbial, faunal and plant communities as well as the metabolic processes in the soil-, rhizo- and phyllosphere are changed by organic manuring. Consequences for the soil carbon-, nitrogen-and phosphorus-cycle are discussed. Impacts of heavy metals and hazardous organics on the soil biomass and its habitat as well as on transport mechanisms and surival times of disseminated pathogens in soils are reviewed with emphasis on the German situation. A proposal for future strategies (landscape recycling) is made.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00750669
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    Share of agriculture in nitrogen and phosphorus emissions into the surface waters of Western Europe against the background of their eutrophication (1990)
    Springer
    Nutrient cycling in agroecosystems 26 (1990), S. 253-269 
    Details
    ISSN: 1573-0867
    Keywords: Nitrogen ; phosphorus ; sulphur ; nutrient balances ; surface waters ; North Sea ; Baltic Sea ; eutrophication ; hypertrophication ; primary production
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Dissolved inorganic nitrogen and phosphorus, their relationship to each other (DIN/DIP) as predisposing (nutrient) factors, as well as prevailing weather as a triggering factor all work together to induce the primary production and hence the eutrophication (hypertrophication) process in surface waters. Sulfate likewise is a decisive predisposing factor influencing the eutrophication process by reducing N availability but increasing P availability and thus acting towards an N limitation of the primary production. This is one of the reasons why marine (coastal) waters and estuaries often exhibit N limitation with respect to primary production, while freshwater ecosystems often tend to exhibit P limitation. Within the N and P balance of agriculture of some countries of Western Europe (Netherlands, Denmark, Switzerland, FRG, UK and Sweden for N, resp. Netherlands, FRG and GDR for P) more the level than the efficiency of the N and P applications indicates the extent of the nutrient surplus. Despite 59–73% N utilization in plant production, the rate of 13–23% for agriculture as a whole equals to the 12–21% efficiency of N use in animal production. The varying N surplus in agriculture in the separate countries of 124 to 465 kg N ha−1 a−1 is determined almost exclusively by the level of the N application and not by its efficiency. The situation is similar for P: In spite of P utilization in plant production of 59–76%, P utilization in total agriculture is only 11–38%, or comparable to the P efficiency within animal production of 10–34%. The differing P excess balance of 55 to 88 kg P2O5 ha−1 a−1 is influenced by the level of the P application. The N and P efficacy of total agriculture hence is determined almost completely by that of animal production, since 83–95% (N basis) and 76–94% (P basis) of the total plant production (on top of the nationally varying levels of N and P use via imported feeds) are fed to animals — with the low N and P utilization cited above. Agriculture's share of the N and P emissions into surface water of several countries/regions in Western Europe (FRG, Netherlands, Italy, Denmark, Switzerland, Norway) ranges from 37 to 82% resp. 27 to 38%. Its share in the flus into the North Sea catchment basin will be about 60% for N and 25% for P related only to the anthropogenic material carried by the rivers. Agriculture's share in the atmospheric N emissions into the North and Baltic Seas can be estimated at about 65% or 55%, resp. while the remaining approx. 35% or 45%, resp. are traceable primarily to anthropogenic burning processes. For agriculture the priority lies in limiting N emissions into surface water caused by leaching, erosion and NH3 emissions, and reducing P emissions mainly through soil conservation (protection against erosion) and water protection. As regards N this means a demand for comprehensive protection of groundwater and atmosphere differentiated according to the potential for losses or the risk of losses on a site, also outside the protection zones. As regards P only those areas can be included in the demand for reduction of emissions that are actually threatened by erosion or surface runoff. Plenty of short-term and long-term measures are available to agriculture to reduce N and P emissions. Especially the long-range measures (such as creating nutrient balances on farms and fields, the integration of animal and plant production, maintaining maximum livestock densities according to the ability of areas to absorb nutrients, altered feeding programs in animal nutrition, changes in livestock keeping (slurry→deep litter), increasing the internal and external recycling of N and P) are capable of bringing about a satisfactory degree of success within the next 20 to 30 years.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01048764
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    Land application of poultry litter and water quality in Oklahoma, U.S.A. (1994)
    Springer
    Nutrient cycling in agroecosystems 40 (1994), S. 165-173 
    Details
    ISSN: 1573-0867
    Keywords: Animal manure ; eutrophication ; ground water ; nitrogen ; phosphorus ; surface runoff
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract With the rapid growth of the poultry industry in Oklahoma, U.S.A., more litter is applied to farm land. Thus, information is required on the impact of applications on regional soil and water resources. The effect of soil and poultry litter management on nitrogen (N) and phosphorus (P) loss in runoff and subsurface flow from four 16 m2 plots (Ruston fine sandy loam, 6 to 8% slope) was investigated under natural rainfall. Plots under Bermudagrass (Cynodon dactylon) received 11 Mg litter ha−1, which amounts to contributions of approximately 410 kg N and 140 kg P ha−1 yr−1. In spring, litter was broadcast on 3 of the plots; the upper half of one and total area of the other two. One of the total-area broadcast plots was tilled to 6 cm, the other remained as no till. The fourth plot served as a control. Relative to the control, litter application increased mean concentrations of total N and total P in runoff during the 16-week study for no-till (15.4 and 5.8 mg L−1) and tilled treatments (16.7 and 6.1 mg L−1). However, values for the half-area application (5.6 and 2.0 mg L−1) were similar to the control (5.7 and 1.3 mg L−1). Interflow (subsurface lateral flow at 70 cm depth) P was not affected by litter application; however, nitrate-N concentrations increased from 0.6 (control) to 2.9 mg L−1 (no till). In all cases, 〈 2 % litter N and P was lost in runoff and interflow, maintaining acceptable water quality concentrations. Although litter increased grass yield (8518 kg ha−1) compared to the control (3501 kg ha−1), yields were not affected by litter management. An 8-fold increase in the plant available P content of surface soil indicates long-term litter management and application rates will be critical to the environmentally sound use of this nutrient resource.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00750462
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    An economic evaluation of a long-term experiment on phosphorus and manure amendments to sandy Sahelian soils: Using a stochastic dominance model (1992)
    Springer
    Nutrient cycling in agroecosystems 33 (1992), S. 193-202 
    Details
    ISSN: 1573-0867
    Keywords: manure ; Niger ; phosphorus ; Sahelian soils ; stochastic dominance framework
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Poor fertility status of sandy Sahelian soils represents a major constraint to cereal and legume production. Soil amendment options were evaluated, using a stochastic efficiency framework. Dominance analyses showed that in the presence of annual applications of 30 kg N ha−1 and 30 kg K ha−1, efficient soil amendment options comprise of either the annual application of 8.7 kg P ha−1 in the form of single superphosphates in combination with 5 tonnes manure ha−1 applied every three years or the annual application of 17.5 kg P ha−1 in the form of single superphosphates. Choice between these two efficient options depends on the availability of manure, deficiencies in sandy soils and farmer resource endowments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01050874
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    The interpretation of Olsen extractable P values in relation to recommendations for the fertilizer requirements of crops (1992)
    Springer
    Nutrient cycling in agroecosystems 32 (1992), S. 223-227 
    Details
    ISSN: 1573-0867
    Keywords: Soil testing ; phosphorus ; relative yield
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A greenhouse experiment, with Okra (Abelmoschus esculentus L.) as the test crop, was conducted on twenty-one soils ranging in Olsen's extractable phosphorus from 1.8 to 15.5µg Pg−1 soil. The experiment was conducted at Punjab Agricultural University, Ludhiana, India. The soils were nonsaline with pH ranging from 7.7 to 8.6. A critical level of 2.55µg Pg−1 soil was predicted by Cate and Nelson's (1971) statistical procedure. Because of a wide range in relative yields, this value did not accurately predict response to applied P. An approach to compute minimum response to applied fertilizer, which is likely to be obtained at a particular Olsen P level, has been presented. It involves calculation of lower 60 percent confidence limits for relative yield and fitting loge-linear regression to the transformed data. The regression was tested on a published data set and was found to hold well.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01048784
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    Two post thinning fertilizer trials inPinus radiata in New South Wales, Australia (1992)
    Springer
    Nutrient cycling in agroecosystems 32 (1992), S. 259-267 
    Details
    ISSN: 1573-0867
    Keywords: Nitrogen ; phosphorus ; timber increment ; fertilization ; Pinus radiata
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Two trials inPinus radiata growing on different sites in N.S.W. allowed consideration of fertilizer applications after 2nd or 3rd thinning. The trials included factorial applications of N and P at a single thinning intensity plus a further treatment which allowed assessment of different thinning intensities. The most significant growth responses were obtained by application of N and P in combination. The largest response (additional productivity compared with the unfertilized control) occurred 4 years after application and after 7 years there was no additional absolute response for either of the two sites. The largest fertilizer response was 70 m3 ha−1 over 7 years on one site and 36 m3 ha−1 on the other, indicating differences in absolute responses between sites. It was concluded that in planning treatments the most responsive sites near the end of the rotation should be selected to maximise economic returns. Foliage analyses indicated differences between sites at the commencement of the study. It was concluded that either a single year of foliage analyses at study commencement is of value, or sampling every year of the study should be used to analyse responses, but a single year of analysis during or at the end of the study would not be of value.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01050363
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    Effect of phosphate on the sorption, desorption and plant-availability of selenium in soil (1994)
    Springer
    Nutrient cycling in agroecosystems 39 (1994), S. 189-197 
    Details
    ISSN: 1573-0867
    Keywords: interaction ; isotopic exchange ; phosphorus ; plant-availability ; selenium ; soil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Phosphate, applied at 5µg P cm−3, decreased selenite sorption by from 30–70% in three soils studied. Both maximum sorption (Xm) and the binding-energy of sorption as indicated by the binding-energy related constant (k) or the molar free energy (ΔG) of the sorption reaction derived from the Langmuir equation were considerably decreased. On the other hand, phosphate sorption was decreased by increasing concentration of selenite from 0.2µg Se cm−3 to 1.0µg Se cm−3 in the initial solution. The competitive sorption of phosphate with selenite was likely the main mechanism involved in the P-Se interactions. The competitively sorbed selenite exhibited much larger desorption in 0.01M CaCl2 solution, more readily extractable to 0.5M NaHCO3 and significantly higher isotopic exchangeability compared to that sorbed without the competing anion. Results from pot trial using ryegrass indicated that phosphate application increased more efficiently the plant-availability of applied fertilizer Se than that of indegeneous Se in soil.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00750246
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    Double labeling of mRNA and protein markers in cultured embryoid bodies (1994)
    Springer
    Methods in cell science 16 (1994), S. 11-16 
    Details
    ISSN: 1573-0603
    Keywords: Differentiation ; DIG-mRNA ; Embryoid bodies ; ES cell ; Immunocytochemistry ; In situ hybridization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In vitro suspension cultures of embryonal carcinoma or embryonic stem cells (EC/ES) generate cell aggregates termed as embryoid bodies (EBs). EBs have been analyzed to study the mechanisms of cellular differentiation in vitro. The multipotency of EC/ES cells to differentiate into various cell types as well as the expression of many marker genes provides a valuable in vitro model system to study the mechanisms of cellular differentiation. Here we present a procedure for a mRNA detection of a specific gene using double labeling-mRNA probe and an antibody against cellular marker proteins. This double labeling analysis in combination with a culture of EBs provides a useful approach to analyze several mechanisms of cellular differentiation from multipotent EC/ES cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01404831
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 53
    Electronic Resource
    Electronic Resource
    Soil nutrient dynamics in response to irrigation of a Panamanian tropical moist forest (1992)
    Springer
    Biogeochemistry 19 (1992), S. 1-25 
    Details
    ISSN: 1573-515X
    Keywords: nitrogen ; phosphorus ; soil fertility ; tropical forest
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract We measured concentrations of soil nutrients (0–15 and 30–35 cm depths) before and after the dry season in control and dry-season irrigated plots of mature tropical moist forest on Barro Colorado Island (BCI) in central Panama to determine how soil moisture affects availability of plant nutrients. Dry-season irrigation (January through April in 1986, 1987, and 1988) enhanced gravimetric soil water contents to wet-season levels (ca. 400 g kg−1 but did not cause leaching beyond 0.8 m depth in the soil. Irrigation increased concentrations of exchangeable base cations (Ca2+, Mg2+, K+, Na+), but it had little effect on concentrations of inorganic N (NH4 +C, NO3 − and S (SO4 2−). These BCI soils had particularly low concentrations of extractable P especially at the end of the dry season in April, and concentrations increased in response to irrigation and the onset of the rainy season. We also measured the response of soil processes (nitrification and S mineralization) to irrigation and found that they responded positively to increased soil moisture in laboratory incubations, but irrigation had little effect on rates in the field. Other processes (plant uptake, soil organic matter dynamics) must compensate in the field and keep soil nutrient concentrations at relatively low levels.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00000572
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 54
    Electronic Resource
    Electronic Resource
    Nutrient limitations to plant growth during primary succession in Hawaii Volcanoes National Park (1993)
    Springer
    Biogeochemistry 23 (1993), S. 197-215 
    Details
    ISSN: 1573-515X
    Keywords: chronosequence ; montane tropical forest ; nitrogen ; soil development ; phosphorus ; tropical forest
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract We determined the effects of nutrient amendments on plant growth in three tropical montane rainforest sites representing a sequence of soil ages (〈 30, 200, and ≈ 2000 y). Factorial fertilization with nitrogen, phosphorus, and all other essential nutrients (combined) was applied to the two younger sites; only nitrogen was applied to the oldest one. Nitrogen supply represented the most important limitation to plant growth in the two younger sites; additions of nitrogen caused significant increases in tree diameter increment, height growth, litterfall, and most other growth-related parameters. In contrast, nitrogen additions had no significant effect on plant growth in the oldest site. Phosphorus additions increased extractable soil phosphorus and plant tissue phosphorus, but did not increase plant growth at the young sites. The results are consistent with Walker & Syers' (1976) model for the control of nutrient limitation during soil development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00023752
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    Lime-aluminium-phosphorus interactions and the growth of Leucaena leucocephala (1990)
    Springer
    Plant and soil 126 (1990), S. 1-8 
    Details
    ISSN: 1573-5036
    Keywords: aluminium ; aluminium toxicity ; Leucaena yield ; lime ; phosphorus ; phosphorus uptake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effects of lime and P addition on the amounts of soil extractable P and Al, and on the growth of the tropical legume Leucaena leucocephala were investigated in a factorial experiment under controlled climate conditions using 4 (Koronivia, Nadroloulou, Batiri, and Seqaqa) highly-weathered, acid (pH initially 3.9 to 4.9) soils from Fiji. Resin-extractable P increased with lime addition and then decreased above pH 5.5, whereas M KCl-extractable Al decreased to undetectable levels at or above pH 5.2. Plant growth was usually adversely affected at low and high pH, even in the presence of added P. The pH (in M KCl) at which maximum growth occurred in the 4 soils varied from approximately 4.4 to 5.2; values somewhat lower than those reported in the literature. Changes in dry matter yield with increasing soil pH were strongly influenced by P status and a positive lime × P interaction was obtained with 3 of the 4 soils. Above pH 5.2, liming decreased the yield of both tops and roots, for reasons which are discussed in part II. The data obtained for extractable soil P and plant P concentrations indicate that P deficiency is a major problem on these soils.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00041363
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    Lime-aluminium-phosphorus interactions and the growth of Leucaena leucocephala (1990)
    Springer
    Plant and soil 126 (1990), S. 9-17 
    Details
    ISSN: 1573-5036
    Keywords: aluminium ; aluminium toxicity ; aluminium-induced P deficiency ; chemical composition ; Leucaena ; lime ; Lolium perenne L ; perennial ryegrass ; phosphorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effects of lime and P on the chemical composition of the tropical legume Leucaena leucocephala were studied in a controlled climate laboratory experiment using 4 (Koronivia, Nadroloulou, Batiri, and Seqaqa) highly-weathered, acid soils from Fiji. For all soils, changes in the concentration of P in the Leucaena tops followed trends similar to the yield response curve, i.e., the concentration of P was highest at the soil pH at which maximum growth occurred. The concentration of Al in plant tops increased on either side of the pH of maximum growth, but Al uptake by the whole plant (tops plus roots) declined steadily with increasing pH. Although complete major (except P) and minor nutrients were added regularly, there was variation in the uptake of nutrients with pH. Poor growth at low pH values was attributed to an Al-induced P deficiency within the plant and at high pH to a soil P deficiency and, to a smaller extent, to the increased concentration of Al in the plant tops.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00041364
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    Plant community dynamics in a semi-arid ecosystem in relation to nutrient addition following a major disturbance (1990)
    Springer
    Plant and soil 126 (1990), S. 91-99 
    Details
    ISSN: 1573-5036
    Keywords: disturbance ; fertilizer ; nitrogen ; nutrient enrichment ; phosphorus ; secondary succession ; species richness
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Effects of annual additions of mineral N and P (100 kg ha−1) on plant species composition and annual aboveground net primary production (ANPP) were investigated during the first three years following disturbance in a semi-arid ecosystem. Additions of N reduced richness of perennial plant species during years 2 and 3, while P reduced the number of perennial species only in year 3. From year 1 to year 2, annual and biennial species richness declined in all treatments while ANPP of annual species increased greatly. Added N increased ANPP of annual species while it decreased ANPP of most perennial species relative to the unfertilized control treatment. Community similarities were higher for the control and native vegetation than for other pairs of treatments using both species presence and plant production data. Nitrogen additions have retarded but not completely arrested secondary succession in this system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00041373
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    Effect of silicon on the growth and phosphorus uptake of rice (1990)
    Springer
    Plant and soil 126 (1990), S. 115-119 
    Details
    ISSN: 1573-5036
    Keywords: inorganic P ; organic P ; P/Fe ; P/Mn ratios ; phosphorus ; rice ; silicon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A pot experiment was conducted to measure the effect of silicon on phosphorus uptake and on the growth of rice at different P levels. Rice (Oryza sativa L. cv. Akebono) was cultured in Kimura B nutrient solution without and with silicon (1.66 mM Si) and with three phosphorus levels (0.014 mM P, low; 0.21 mM, medium; and 0.70 mM, high). Shoot dry weight with Si (+Si) in solution increased with increasing P level, while shoot weight without Si (−Si) was maximum at 0.21 mM P, suggesting that +Si raised the optimum P level for rice. +Si increased shoot weight more when P was low or high than when P was medium. The concentration and amount of inorganic P in shoots increased with increasing P level. +Si did not significantly decrease P uptake by rice at 0.014 mM P, however, uptake at 0.21 and 0.70 mM P was 27 and 30 percent less than uptake with −Si, respectively. In −Si with 0.21 and 0.70 mM P, inorganic P in shoots was more than double the concentration in shoots grown in +Si solutions. The Si concentration in shoots decreased slightly with increasing P level, although Si uptake was not significantly affected by P. +Si decreased the uptake of Fe and Mn by an average of 20 and 50 percent, respectively, thus P/Mn and P/Fe ratios increased in the shoot when P was low. From the results above, the beneficial effect of Si on the growth of rice was clearly shown when P was low or high. This effect may have resulted from decreased Mn and Fe uptake, and thus increased P availability within P deficient plants, or from reduced P uptake when P was high.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00041376
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    Growth of asparagus in a commercial peat mix containing vesicular-arbuscular mycorrhizal (VAM) fungi and the effects of applied phosphorus (1991)
    Springer
    Plant and soil 135 (1991), S. 75-82 
    Details
    ISSN: 1573-5036
    Keywords: asparagus ; peat ; phosphorus ; vesicular-arbuscular mycorrhiza
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Commercially prepared, peat-based mycorrhizal inocula were studied for growth effects on asparagus grown under greenhouse and field (fumigated) conditions. The fungi tested were Glomus clarum (GC), G. intraradix (GI), G. monosporum (GM), G. versifomre (GVR) and G. vesiculiferum (GVS). GI significantly increased plant dry weight in the greenhouse and the field. Survival of mycorrhizal tissue-cultured transplants after 14 months in the field was increased by twofold over the control. In a second experiment asparagus was grown from seed in the greenhouse in peat inoculated with a G. fasciculatum-like fungus (GF), GI and GVR with applied P levels of 0, 50, 100 and 150 ppm and harvested after 13 and 17 weeks. Total dry weights of GI and GVR plants were significantly increased over those of the control and GF. Dry weight in this second experiment was positively correlated with root colonization. Root colonization at week 13 was slightly reduced with increasing levels of applied P, but not at week 17. The data suggest that the increased growth of mycorrhizal plants was not related to an increase in tissue P concentration, since there was no growth response to applied P and tissue P concentration in the mycorrhizal plants was lower than in the non-mycorrhizal plants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00014780
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    Response of early and late semiarid seral species to nitrogen and phosphorus gradients (1992)
    Springer
    Plant and soil 140 (1992), S. 127-135 
    Details
    ISSN: 1573-5036
    Keywords: nitrogen ; phosphorus ; root: shoot ratios ; secondary succession ; semiarid ; shrubland ; tissue nitrogen ; tissue phosphorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Above- and below-ground biomass production, nitrogen (N) and phosphorus (P) tissue concentrations, and root: shoot ratios were examined for five species that are characteristic of a semiarid successional sequence under controlled greenhouse conditions. In two simultaneous experiments, seedlings of one forb, two grass, and two shrub species important in a sagebrush successional sere, were subjected to seven levels of N and P. Results of the experiments suggest distinct differences in nutrient response patterns between early and late seral species. Early seral species produced more biomass but had lower tissue nutrient concentrations than late seral species. As N and P availabilities decreased, late seral species displayed characteristics indicative of increasing competitive advantage over those of early seral species. Root: shoot ratios of the five species primarily reflected patterns related to lifeform, but with some early and late seral characteristics. Results from this study 1) confirm that nutrient use pattern, nutrient availability, and seral position relationships characteristic of mesic ecosystems hold equally true for semiarid systems, and 2) suggest that nutrients are important organizing factors in semiarid ecosystems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00012814
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    Nitrogen and phosphorus cycling in relation to stand age of Ecucalyptus regnans F. Muell (1992)
    Springer
    Plant and soil 142 (1992), S. 157-166 
    Details
    ISSN: 1573-5036
    Keywords: Acacia ; Eucalyptus regnans ; decomposition ; litterfall ; nitrogen ; phosphorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The N and P contents of the litter layer and the return of these nutrients in litterfall were measured in seven stands of Mountain Ash (Eucalyptus regnans) ranging in age from 5 years to about 250 years. Both annual litterfall and nutrient return were correlated with stand basal area and were high compared with other productive eucalypt forests. In contrast, the fall of dead eucalypt leaves was constant with stand age, demonstrating that sites are fully occupied at an early age. Similarly, amounts of N and P in total leaf fall (overstorey plus understorey) were constant with stand age, except for low amounts in the stand aged 40 years where Acacia spp., important fixers of atmospheric N, were not prevalent. The decomposition constant (k) of organic matter in the litter layer decreased with stand age, from 0.31 year-1 at age 5 years to 0.23 year-1 at age 250 years. These constants also applied to N and P, indicating a tight coupling between organic matter decomposition and release of these nutrients from litter. The litter layer released about 30 kg ha-1 of N at age 5 years, and about 70 kg ha-1 at age 80 years. These results are discussed in relation to growth of Mountain Ash following fire, and the subsequent retention and accumulation of N during stand development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00010962
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    Influence of plant nutrient concentration on growth rate: Use of a nutrient interruption technique to determine critical concentrations of N, P and K in young plants (1992)
    Springer
    Plant and soil 142 (1992), S. 221-233 
    Details
    ISSN: 1573-5036
    Keywords: critical concentration ; deficiency ; diagnosis ; growth rate ; lettuce ; luxury consumption ; nitrogen ; nitrate ; nutrient requirement ; petiole sap ; phosphorus ; phosphate ; potassium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A method is described for determining the way in which growth rate varies with plant nutrient concentration using a simple nutrient interruption technique incorporating only 2 treatments. The method involves measuring the changes in growth and nutrient composition of otherwise well-nourished plants after the supply of one particular nutrient has been withheld. Critical concentrations are estimated from the relationship between the growth rate (expressed as a fraction of that for control plants of the same size which remained well-nourished throughout) and the concentration of the growth-limiting nutrient in the plants as deficiency developed. Trials of the method using young lettuce plants showed that shoot growth rate was directly proportional to total N (nitrate plus organic N) concentration, and linearly or near-linearly related to K and P concentration over a wide range; the corresponding relationship for nitrate was strongly curvi-linear. Critical concentrations (corresponding to a 10% reduction in growth rate) determined from these results were similar to critical values calculated from models derived from field data, but were generally higher than published estimates of critical concentration (based on reductions in shoot weight) for plants of a similar size. Reasons for these discrepancies are discussed. Nitrate, phosphate or potassium concentrations in sap from individual leaf petioles were highly sensitive to changes in shoot growth rate as deficiency developed, with the slope of the relationships varying with leaf position, due to differences both in their initial concentration and in the rates at which they were utilized in individual leaves. Each nutrient was always depleted more quickly in younger leaves than in older ones, providing earlier evidence of deficiency for diagnostic purposes. Although the plants were capable of accumulating nitrate, phosphate and potassium well in excess of that needed for optimum dry matter production during periods of adequate supply, the rate of mobilization of these reserves was insufficient to prevent reductions in growth rate as the plants became deficient. This brings into question the validity of the conventional concept that luxury consumption provides a store of nutrients which are freely available for use in times of shortage. The implications of these results for the use of plant analysis for assessing plant nutrient status are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00010968
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    Response of mesquite to nitrate and salinity in a simulated phreatic environment: Water use, dry matter and mineral nutrient accumulation (1990)
    Springer
    Plant and soil 125 (1990), S. 185-196 
    Details
    ISSN: 1573-5036
    Keywords: calcium ; copper ; desert ; ground water ; iron ; magnesium ; manganese ; nitrogen ; phosphorus ; Prosopis glandulosa ; rooting patterns ; sodium ; symbiotic nitrogen fixation ; trace metals ; water table ; water use efficiency ; zinc
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Mesquite plants (Prosopis glandulosa var. Torreyana) were grown in 2-m long columns 20 cm in diameter, and provided with a constant, stable ground water source 10 cm above the sealed base of the column. Ground water contained 0, 1 or 5 mM nitrate, or a mixed salt solution (1.4, 2.8, or 5.6 dS m-1) with the ionic ratios of ground water found in a field stand of Prosopis at Harper's Well (2.8 dS m-1). Water uptake in the highly salinized columns began to decrease relative to low salt columns when soil salinity probes 30 cm above the column base read approximately 28 dS m-1, a potential threshold for mesquite salt tolerance. Prosopis growth increased with increasing nitrate, and decreased with increasing salinity. Water use efficiency was little affected by treatment, averaging approximately 2 g dry matter L-1 water used. Most fine roots were recovered from a zone about 25 cm above the ground water surface where water content and aeration appeared to be optimal for root growth. Root-shoot ratio was little affected by nitrate, but increased slightly with increasing salinity. Plant tissue P concentrations tended to increase with increasing salinity and decrease with increasing N, approaching potentially deficient foliage concentrations at 5 mM nitrate. The whole-plant leaf samples increased in sodium concentration both with added salt and with added nitrate. Foliar manganese concentrations increased with increasing salt in the absence of nitrate. Concentrations of sodium in leaves were low (〈10 g kg-1), considering the high salt concentrations in the ground water. Prosopis appears to exclude sodium very effectively, especially from its younger leaves. Although Prosopis is highly salt tolerant, the degree to which it utilizes soil nitrate in place of biologically fixed N may lower its salinity tolerance and affect its nutrient relations in phreatic environments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00010656
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    Sowing date and phosphorus utilization by wheat (1993)
    Springer
    Plant and soil 155-156 (1993), S. 297-300 
    Details
    ISSN: 1573-5036
    Keywords: efficiency ; phosphorus ; sowing time ; vernalization ; winter wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The uptake and utilization of phosphorus (P) by cereal crops is influenced by the growing period of the crop. In this article the effect of sowing date on the utilization of P by wheat crops grown in southern NSW is reviewed. Crops sown early in the accepted sowing period require smaller inputs of P fertilizer to reach the maximum yield but produce grain with a higher concentration of P than crops sown late in the sowing season. For later sowings a higher rate of applied P is required to achieve the yield potential but this is not associated with a high grain P concentration or a high rate of removal of P from the soil. If grain with a high P concentration is required as seed for subsequent crops, then sowing early, even with little or no applied P fertilizer, is preferable, although crops sown early in the season are likely to remove more P from the soil than the amount applied in fertilizer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00025041
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    Mycorrhizal responses of barley cultivars differing in P efficiency (1993)
    Springer
    Plant and soil 157 (1993), S. 97-105 
    Details
    ISSN: 1573-5036
    Keywords: barley cultivars ; efficiency ; Glomus etunicatum ; Hordeum vulgare ; low temperature ; phosphorus ; response ; VA mycorrhiza
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The purpose of this study was to investigate how barley cultivars which are different in dry matter yield at low phosphorus (P) supply (i.e. they differ in agronomic P efficiency) respond to mycorrhizal infection. In a preliminary experiment, six mycorrhizal fungi were tested for their ability to colonize barley (Hordeum vulgare L.) roots at a soil temperature of 15°C.Glomus etunicatum was the most effective species and was used in the main experiment. The main experiment was conducted under glasshouse conditions in which soil temperature was maintained at 15°C. Treatments consisted of a factorial arrangement of 8 barley cultivars, 2 mycorrhiza (inoculated and non-inoculated), and 3 rates of P (0, 10 and 20 mg kg-1). P utilization efficiency (dry matter yield per unit of P taken up) and agronomic P efficiency among the barley cultivars was significantly negatively correlated with mycorrhizal responses. However, the response to mycorrhizal infection was positively correlated with response to P application. Poor correlation was observed between P concentration when neither mycorrhiza nor P were supplied and the percentage of root length infected. The extent of mycorrhizal infection among the barley cultivars in soil without P amendment varied from 8.6 to 28.6%. Significant interactions between cultivar and P addition, and between mycorrhiza and P addition were observed for shoot dry weight but not root dry weight.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02390231
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    Can maize cultivars with low mineral nutrient concentrations in the grains help to reduce the need for fertilizers in third world countries? (1992)
    Springer
    Plant and soil 146 (1992), S. 227-231 
    Details
    ISSN: 1573-5036
    Keywords: cultivars ; grains ; maize ; nitrogen ; phosphorus ; potassium ; tropical climate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract An earlier study revealed considerable genotypic variation in grain N, P and K concentrations (GNC, GPC and GKC, respectively) in tropical maize. The expression of varietal differences in GNC, GPC and GKC, however, may depend on environmental conditions such as the N status of the soil. Two tropical maize hybrids (Suwan 2301 and CP 1) with comparable yielding capacity, but contrasting GNCs, GPCs and GKCs, were therefore grown at four levels of N in a field experiment at Farm Suwan (Thailand, latitude 14.5°N). Suwan 2301 exhibited a higher GNC than did CP 1 at all rates of N, but large differences in GPC and GKC were found only at high N fertilization. This was obviously due to individual grain yield responses of the cultivars to increasing rates of N fertilizer, demonstrating that grain nutrient concentrations are, at least in part, functions of the amount of grain carbohydrates which dilute a genetically and environmentally fixed amount of grain P and K. As compared to Suwan 2301, CP 1 accumulated less N, P and K in the grains at almost all levels of N fertilization, confirming our hypothesis that the cultivation of maize genotypes with low grain mineral nutrient concentrations may help third-world cash-crop farmers to reduce the need for scarce and costly mineral fertilizers. This finding has to be verified at reduced availability of soil −P, −K, and water.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00012016
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    Desorption and plant-availability of phosphate sorbed by some important minerals (1994)
    Springer
    Plant and soil 162 (1994), S. 89-97 
    Details
    ISSN: 1573-5036
    Keywords: desorption ; phosphorus ; rice ; variable-charge mineral
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Experiments were conducted to study the desorption characteristics and plant-availability of phosphate sorbed by some important variable-charge minerals including kaolinite, goethite and amorphous Al oxide. Phosphate desorption from the complexes of goethite-P, kaolinite-P and Al oxide-P by equilibration with 0.02M KCl, resin or some commonly used chemical extractants was slow compared to desorption from a permanent-charge mineral (montmorillonite). However, rice plants were not observed under P deficiency in a pot trial with a phosphate-mineral complex as the only P source for both the permanent-charge mineral and the variable-charge minerals at either 50% or 100% sorption saturation with the exception of goethite-P at 50% saturation. In the exceptional goethite-P treatment, plant P concentration (1.0 g kg−1) was on the threshold of P deficiency. From 15% to 31% of the applied P was recovered by the plants within a growing period of three months, depending on sorption saturation and mineral type. Both the dry matter yield and P uptake decreased with decreasing sorption saturation for all the tested complexes except for Al oxide-P100 (100% saturation). In the case of Al oxide-P100, Al toxicity may have occurred, for poor root growth and high Al concentration in the plants were observed. The effect of sorption saturation on the yield and P uptake of plant was obvious for kaolinite and goethite but not very significant for montmorillonite. Based on the recovery of applied P, the plant-availability decreased in the following order: kaolinite-P100 〉 goethite-P100 〉 Al oxide-P50 〉 montmorillonite-P100 〉 montmorillonite-P50 〉 kaolinite-P50 〉 goethite-P50. Fractionation of the sorbed P before and after plant uptake showed that most of the P uptake originated from the resin-exchangeable P fraction in montmorillonite-P complex, but came mainly from NaOH-extractable fractions in goethite-P complex, whereas all the resin-P, NaHCO3-P and NaOH-P fractions in kaolinite- and amorphous Al oxide-P complex made a contribution to P uptake.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01416093
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    Response ofStylosanthes guianensis to endomycorrhizal fungi inoculation as affected by lime and phosphorus applications (1993)
    Springer
    Plant and soil 150 (1993), S. 109-116 
    Details
    ISSN: 1573-5036
    Keywords: liming ; nutrient uptake ; phosphorus ; Stylosanthes guianensis ; tropical soil ; vesiculararbuscular mycorrhiza
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The nutrient concentration in the shoots ofStylosanthes guianensis (Aubl.) Sw. cultivated in a sterilized acid and dystrophic soil (Quartzipsament) amended with 4 levels of lime (0; 0.27; 0.63 and 1.10 meq Ca2+/100 g soil, as Ca(OH)2), 2 levels of P (0 and 20 mg P kg-1 soil, as KH2PO4) and not-inoculated or inoculated with 3 vesicular-arbuscular (VA) mycorrhizal fungi was evaluated under greenhouse conditions. The effectiveness of the different fungal species in increasing the nutrient concentration in the shoots varied with the different edaphic conditions. In general, mycorrhiza formation was associated with increases in the concentrations of most of the nutrients analyzed. Under the experimental conditions, the increments in nutrient concentration were higher overall in plants inoculated withAcaulospora scrobiculata. Inoculation ofS. guianensis with VA mycorrhizal fungi was also associated with alterations in the ratios of nutrients in the shoots, which might be important in understanding and explaining the tolerance of mycorrhizal plants to nutritional stresses such as Al and Mn toxicity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00779181
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    Effect of elevated CO2 on mycorrhizal colonization of loblolly pine (Pinus taeda L.) seedlings (1994)
    Springer
    Plant and soil 165 (1994), S. 81-88 
    Details
    ISSN: 1573-5036
    Keywords: carbohydrates ; ectomycorrhizae ; elevated CO2 ; phosphorus ; Pinus taeda L. ; Pisolithus tinctorius (Pers.) Coker & Couch
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Interactive effects of elevated atmospheric CO2 and phosphorus supply on mycorrhizal colonization rates were investigated using loblolly pine (Pinus taeda L.) seedlings from Florida and coastal North Carolina. Seedlings from both populations were grown in greenhouses maintained at either 35.5 Pa or 71.0 Pa CO2. In both CO2 treatments, seedlings were grown in a full factorial experiment with or without mycorrhizal inoculum and with an adequate or a limiting supply of phosphorus. Seedlings were harvested 60, 90 and 120 days after emergence and at each harvest root subsamples were examined to determine the percent of fine roots that were mycorrhizal. Additionally, root carbohydrate and nutrient levels were measured at each harvest. Root starch, sugar and total non-structural carbohydrate (TNC) concentrations were increased by growth in elevated CO2 and decreased by mycorrhizal colonization. Phosphorus stress decreased root starch concentrations, increased root sugar concentrations and did not significantly affect TNC concentrations. However, despite significant effects on root carbohydrate levels, there were generally no significant treatment effects on mycorrhizal colonization. Additionally, at all harvests, root starch and sugar concentrations were not correlated with percent of fine roots that were mycorrhizal. These results suggest that although elevated CO2 may significantly increase root carbohydrate levels, the increases may not affect the percent of fine roots that are mycorrhizal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00009965
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    Gonadotropin-releasing hormone (GnRH) pathways and reproductive control in elasmobranchs (1993)
    Springer
    Environmental biology of fishes 38 (1993), S. 209-218 
    Details
    ISSN: 1573-5133
    Keywords: Terminal nerve ; Midbrain ; Immunocytochemistry ; Reproduction ; Brain ; Sharks ; Rays ; Skates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Immunoreactive (ir) gonadotropin-releasing hormone (GnRH) is localized in many neurons of the terminal nerve (TN) and midbrain tegmentum, while few ir-cells are observed in the preoptic area and ventral hypothalamus. The paucity of preoptic ir-cells may relate to an unusual feature of the elasmobranch pituitary, i.e. a lack of portal control of gonadotropin-producing cells. TN and midbrain GnRH-ir neurons may be major sources of GnRH used to modulate or otherwise control both pituitary and brain cells via delivery through the systemic circulation. These ir-nuclei also appear to directly innervate CNS regions (the preoptic area, habenula and clasper control area of the spinal cord) involved in sexual functions. Important regulatory mechanisms, represented by interactions between GnRH pathways and sex-steroid concentrating neurons, are likely to occur in the preoptic area, habenula and midbrain tegmentum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00842917
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    Nutrient dynamics in the floodplain ponds of the Paraná River (Argentina) dominated by the water hyacinth Eichhornia crassipes. (1992)
    Springer
    Biogeochemistry 17 (1992), S. 85-121 
    Details
    ISSN: 1573-515X
    Keywords: nitrogen fixation ; phosphorus ; internal loading ; water hyacinth ; floodplain ; Paraná ; flood-pulse hypothesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract Some aspects of nutrient status and dynamics prevailing during low and high water conditions in the fringing floodplain ponds of the Paraná River dominated by the floating macrophyte Eichhornia crassipes are described. During summertime low water conditions, low DIN:DRP ratios (0.16–1.0) and low DIN (0.5–4.8 μmol.liter−1) in the root-zone of the floating meadows suggest that macrophyte growth is limited by nitrogen. DRP concentrations appear to be controlled more by abiotic sorption-dissolution than by biological reactions. Preflood nutrient fluxes from the sediments, as estimated from porewater profiles, show that a minimum of 1.19 and 0.38 mmol.m−2.d−1 of DIN and DRP were regenerated from the sediments, respectively. Heterotrophic N2 fixation is primarily associated with decaying litter (0.4 to 3.2 μmolN2.g−1.d−1). Nutrient recycling from sediments and meadow-litter, and heterotrophic N2 fixation (1.4 mmolN.m−2.d−1) appear sufficient to sustain high floating macrophyte productivity for long periods of time, without invoking large inputs from the river. The high water and early isolation periods are characterized by a very dynamic behavior of DIN, reflecting marked imbalances between N supply and demand by the biota. After hydrologic isolation of the ponds, DIN rapidly decreases to undetectable levels and stays low for the following 3 weeks, presumably as a result of high demand by phytoplankton and sediment bacteria. DIN increases again to high values 3–8 weeks after the flood, following the re-establishment of NH4 + fluxes from the sediments. Compared to DIN, DRP concentrations remain relatively high and change little during and after the flood. Because of their small amplitude and short duration, floods do not appear to stimulate floating macrophyte production in the Paraná.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00002642
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    Effects of nitrogen: phosphorus supply ratios on nitrogen fixation in agricultural and pastoral ecosystems (1992)
    Springer
    Biogeochemistry 18 (1992), S. 19-35 
    Details
    ISSN: 1573-515X
    Keywords: Dinitrogen fixation ; nitrogen ; phosphorus ; competition ; legumes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract An analysis of data compiled from the literature confirms a strong inverse relationship between annual rates of nitrogen fixation and the soil nitrogen content in agricultural and pastoral ecosystems. However, this inverse relationship is strongly modified by the rate of application of phosphorus fertilizer, which strongly influences the activities of both symbiotic and non-symbiotic nitrogen fixing organisms. In the case of symbiotic legumes, the response of N-fixation to N and P is in part a result of changes in legume dominance within the plant community. These results, as well as supporting data presented from a review of experiments on nitrogen fixation in a variety of other terrestrial and aquatic ecosystems, provide important support for the hypothesis that phosphorus availability is a key regulator of nitrogen biogeochemistry.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00000424
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    A comparison of phosphorus immobilization in sediments of freshwater and coastal marine systems (1990)
    Springer
    Biogeochemistry 9 (1990), S. 277-290 
    Details
    ISSN: 1573-515X
    Keywords: phosphorus ; sediment loading ; marine vs freshwater
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract The extent to which sediments of aquatic systems immobilize or release phosphorus can affect dramatically the P content of overlying waters. Data from 48 different aquatic systems suggests that there may be a major difference between fresh- and salt-water systems in this immobilization. Under oxic conditions (water overlying sediments had dissolved oxygen 〉 0.5 mg/L) P is strongly immobilized in sediments of most fresh-water systems. In sediments of most salt-water systems P is released from sediments and behaves, essentially, as a conservative tracer of benthic decomposition. This difference in P cycling is large enough to have an influence on the often cited difference in phytoplankton nutrient limitation between fresh- and salt-water systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00000602
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    Stoichiometric relationships among producers, consumers and nutrient cycling in pelagic ecosystems (1992)
    Springer
    Biogeochemistry 17 (1992), S. 49-67 
    Details
    ISSN: 1573-515X
    Keywords: algae ; nitrogen ; nutrient ; phosphorus ; regeneration ; zooplankton
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract Most ecosystem models consolidate members of food-webs, e.g. species, into a small number of functional components. Each of these is then described by a single state variable such as biomass. When a multivariate approach incorporating multiple substances within components is substituted for this univariate one, a ‘stoichiometric’ model is formed. Here we show that the Nitrogen:Phosphorus ratio within zooplankton herbivores varies substantially intraspecifically but not intraspecifically. By using stoichiometric theory and recent measurements of the N:P ratio within different zooplankton taxa, we calculate large differences in ratios of nutrients recycled by different zooplankton species. Finally, we demonstrate that N:P stoichiometry can successfully account for shifts in N- and P-limitation previously observed in whole-lake experiments. Species stoichiometry merges food-web dynamics with biogeochemical cycles to yield new insights.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00002759
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    Assessment of nutrient availability and limitation using macroalgae (1994)
    Springer
    Journal of aquatic ecosystem stress and recovery 3 (1994), S. 27-34 
    Details
    ISSN: 1573-5141
    Keywords: nutrient limitation ; critical tissue concentrations ; nitrogen ; phosphorus ; macroalgae ; biomonitoring
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Discs of the macroalga,Ulva lactuca L., were transplanted around an ocean outfall and at a reference site in Køge Bay, Denmark, to assess the influence of the outfall on the nutrient availability. At 2-wk intervals, samples were collected and analyzed for growth, nitrogen, and phosphorus content. The tissue concentrations of nitrogen and phosphorus decreased with distance to the outfall, showing that the tissue concentrations are suitable for monitoring nutrient availability in coastal areas and provide a time-integrated measure of the nutrient availability. The lowest tissue concentrations of nitrogen were recorded at the reference station, where the internal concentrations generally were below the critical concentration level, showing that nitrogen limited the growth. At the station located close to the outfall, the flux of nitrogen was sufficient to maintain the maximum growth rate. The tissue concentrations of phosphorus were only below the critical concentration level on one occasion, and the result showed a net uptake throughout the study period. It was concluded that in the Køge Bay, nitrogen was the main limiting factor for macroalgae growth during the summer. The applicability of tissue concentrations for assessment of nutrient availability is discussed and it is considered that the method, when evaluated against established critical concentrations, provides a valuable tool for assessing ecosystem health with regard to eutrophication.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00045154
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    The cumulative effect of wetlands on stream water quality and quantity. A landscape approach (1990)
    Springer
    Biogeochemistry 10 (1990), S. 105-141 
    Details
    ISSN: 1573-515X
    Keywords: cumulative ; flow ; GIS ; landscape ; lead ; nitrogen ; phosphorus ; suspended solids ; watershed ; wetlands
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract A method was developed to evaluate the cumulative effect of wetland mosaics in the landscape on stream water quality and quantity in the nine-county region surrounding Minneapolis—St. Paul, Minnesota. A Geographic Information System (GIS) was used to record and measure 33 watershed variables derived from historical aerial photos. These watershed variables were then reduced to eight principal components which explained 86% of the variance. Relationships between stream water quality variables and the three wetland-related principal components were explored through stepwise multiple regression analysis. The proximity of wetlands to the sampling station was related to principal component two, which was associated with decreased annual concentrations of inorganic suspended solids, fecal coliform, nitrates, specific conductivity, flow-weighted NH4 flow-weighted total P, and a decreased proportion of phosphorus in dissolved form(p 〈 0.05). Wetland extent was related to decreased specific conductivity, chloride, and lead concentrations. The wetland-related principal components were also associated with the seasonal export of organic matter, organic nitrogen, and orthophosphate. Relationships between water quality and wetlands components were different for time-weighted averages as compared to flow-weighted averages. This suggests that wetlands were more effective in removing suspended solids, total phosphorus, and ammonia during high flow periods but were more effective in removing nitrates during low flow periods.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00002226
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    The role of rock weathering in the phosphorus budget of terrestrial watersheds (1990)
    Springer
    Biogeochemistry 11 (1990), S. 97-110 
    Details
    ISSN: 1573-515X
    Keywords: phosphorus ; stream chemistry ; weathering
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract Residual soils (saprolites) developed on crystalline rocks appear to form by an essentially isovolumetric process (i.e. without dilation or compaction). Isovolumetric geochemical analysis of a suite of saprolite samples developed on a common parent rock can be used to estimate the relative rates of long-term losses of P and Si during weathering. Using the export of dissolved Si in rivers as a weathering index, one can then estimate the rate of P release due to chemical weathering by means of the P-Si loss ratio in saprolite. For three basins where data are available (Liberty Hill, SC; Amazon River, Brazil: Rio Negro, Brazil) estimated P weathering release rates are 163, 457, and 242 moles P km−2 yr−1 respectively. These compare to precipitation inputs of 684, 700 and 630 moles P km−2 yr−1 and total river exports of 256, 4490 and 820 moles P km−2 yr−1, respectively. The Rio Negro shows a near perfect balance between the input of P via precipitation and chemical weathering and the riverine output of dissolved and suspended P. This system, however, raised the unsolved problem of the source that supports the atmospheric P input.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00002061
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    Control of plant growth by nitrogen and phosphorus in mesotrophic fens (1991)
    Springer
    Biogeochemistry 12 (1991), S. 135-148 
    Details
    ISSN: 1573-515X
    Keywords: fens ; management ; nitrogen ; phosphorus ; productivity ; vegetation ; wetlands
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract A fertilization experiment was carried out in 3 mesotrophic fens to investigate whether plant growth in these systems is controlled by the availability of N, P or K. The fens are located in an area with high N inputs from precipitation. They are annually mown in the summer to prevent succession to woodland. Above-ground plant biomass increased significantly upon N fertilization in the two “mid”-succession fens studied. In the “late”-succession fen that had been mown for at least 60 years, however, plant biomass increased significantly upon P fertilization. The mowing regime depletes the P pool in the soil, while it keeps N inputs and outputs in balance. A long-term shift occurs from limitation of plant production by N toward limitation by P. Hence, mowing is a suitable management tool to conserve the mesothrophic character of the fens.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00001811
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    Nitrogen limitation on land and in the sea: How can it occur? (1991)
    Springer
    Biogeochemistry 13 (1991), S. 87-115 
    Details
    ISSN: 1573-515X
    Keywords: biogeochemistry ; energetic constraints ; nitrogen fixation ; phosphorus ; succession ; trace elements
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract The widespread occurrence of nitrogen limitation to net primary production in terrestrial and marine ecosystems is something of a puzzle; it would seem that nitrogen fixers should have a substantial competitive advantage wherever nitrogen is limiting, and that their activity in turn should reverse limitation. Nevertheless, there is substantial evidence that nitrogen limits net primary production much of the time in most terrestrial biomes and many marine ecosystems. We examine both how the biogeochemistry of the nitrogen cycle could cause limitation to develop, and how nitrogen limitation could persist as a consequence of processes that prevent or reduce nitrogen fixation. Biogeochemical mechansism that favor nitrogen limitation include: the substantial mobility of nitrogen across ecosystem boundaries, which favors nitogen limitation in the “source” ecosystem — especially where denitrification is important in sediments and soils, or in terrestrial ecosystems where fire is frequent; differences in the biochemistry of nitrogen as opposed to phosphorus (with detrital N mostly carbon-bonded and detrital P mostly ester-bonded), which favor the development of nitrogen limitation where decomposition is slow, and allow the development of a positive feedback from nitrogen limitation to producers, to reduced decomposition of their detritus, and on to reduced nitrogen availability; and other more specialized, but perhaps no less important, processes. A number of mechanisms could keep nitrogen fixation from reversing nitrogen limitation. These include: energetic constraints on the colonization or activity of nitrogen fixers; limitation of nitrogen fixers or fixation by another nutrient (phosphorus, molybdenum, or iron) — which would then represent the ultimate factor limiting net primary production; other physical and ecological mechanisms. The possible importance of these and other processes is discussed for a wide range of terrestrial, freshwater, and marine ecosystems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00002772
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    Phosphorus regulation of nitrogen fixation in a traditional Mexican agroecosystem (1993)
    Springer
    Biogeochemistry 21 (1993), S. 141-166 
    Details
    ISSN: 1573-515X
    Keywords: acetylene reduction ; agroecology ; natural abundance15N ; nitrogen fixation ; phosphorus ; sustainable agriculture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract Although nitrogen is considered to be the nutrient that most commonly limits production of natural and managed terrestrial ecosystems, I propose that phosphorus may regulate productivity in many continuously cultivated agroecosystems that do not receive applications of synthetic fertilizers. One way P may limit agroecosystem productivity is by controlling nitrogen fixation of legume crops, thus affecting nitrogen availability in the overall agroecosystem. I tested this hypothesis in two studies by examining the effect of phosphorus nutrition on nitrogen fixation of alfalfa in traditional Mexican agroecosystems. All farms used in the research relied on alfalfa as the primary nitrogen source for maize cultivation and other crops, and had minimal or no reliance on synthetic fertilizers. In one study, I used the natural abundance of15N to estimate nitrogen fixation in five alfalfa plots with soils representing a wide range of P fertility. I found a correlation of r = 0.85 between foliage P concentrations and nitrogen fixation in the alfalfa plots. Mean nitrogen fixation in alfalfa plots ranged between 232–555 kg ha−1 yr−1 as estimated by the15N-natural abundance method. In a second study, I sampled soils from alfalfa plots on traditional farms located in 5 different physiographic regions of Mexico. Half of each soil sample was augmented with phosphorus in a greenhouse experiment. I grew alfalfa on the fertilized and unfertilized soils from each site and then determined nitrogenase activity (acetylene reduction) of the Rhizobium on the plant roots. Nitrogenase activity increased in the alfalfa grown on all soils with added phosphorus, with two of the five differences being statistically significant at P 〈 0.01, 0 and one at P 〈 0.05. Foliage P concentrations and nitrogenase activity were 0 positively correlated (r = 0.81,P 〈 0.01).0
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00001115
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    Variable rates of phosphate uptake by shallow marine carbonate sediments: Mechanisms and ecological significance (1994)
    Springer
    Biogeochemistry 25 (1994), S. 127-146 
    Details
    ISSN: 1573-515X
    Keywords: carbonate sediments ; phosphate adsorption ; phosphorus ; phosphorus limitation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract We determined phosphate uptake by calcareous sediments at two locations within a shallow lagoon in Bermuda that varied in trophic status, with one site being mesotrophic and the other being more eutrophic. Phosphate adsorption over a six hour period was significantly faster in sediments from the mesotrophic site. Uptake at both sites was significantly less than that reported for a similar experiment on calcareous sediments in an oligotrophic lagoon in the Bahamas. The difference in phosphorus adsorption between our sites did not appear to be related to sediment characteristics often cited as important, such as differences in surface area (as inferred from grain size distributions), total organic matter content, or iron content. However, the sediment total phosphorus contents were inversely related to phosphorus uptake at our sites in Bermuda, and at the previously studied Bahamas site. We hypothesize that phosphate uptake in these calcareous sediments is a multi-step process, as previously described for fluvial sediments or pure calcium carbonate solids, with rapid initial surface chemisorption followed by a slower incorporation into the carbonate solid-phase matrix. Accordingly, sediments already richer in solid phase phosphorus take up additional phosphate more slowly since the slower incorporation of surface-adsorbed phosphate into the carbonate matrix limits the rate of renewal of surface-reactive adsorption sites. Although carbonate sediments are a sink for phosphate, and thereby reduce the availability of phosphorus for benthic macrophytes and phytoplankton in the shallow overlying water, phosphate uptake by these sediments appears to decrease along a gradient from oligotrophic to eutrophic sites. If our result is general, it implies a positive feedback in phosphorus availability, with a proportionately greater percentage of phosphorus loading being biologically available longer as phosphorus loading increases. This pattern is supported by the significantly higher tissue phosphorus content of the seagrass,Thalassia testudinum, collected from the eutrophic inner bay site. Over time, this effect may tend to cause a shift from phosphorus to nitrogen limitation in some calcareous marine environments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00000882
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    Growth retardation induced by nutritional deficiency or abscisic acid in Lemna gibba: The relationship between growth rate and endogenous cytokinin content (1990)
    Springer
    Plant growth regulation 9 (1990), S. 171-181 
    Details
    ISSN: 1573-5087
    Keywords: Lemna gibba ; cytokinins ; isopentenyladenosine ; zeatinriboside ; abscisic acid ; nitrogen ; phosphorus ; relative growth rate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The relationship between endogenous cytokinin content and relative growth rate (RGR) was studied in cultures of Lemna gibba L. G3 supplied with daily doses of mineral nutrients that were increased exponentially over time. At the optimal level of nutrient supply the RGR was 30–35% day-1. The RGR was regulated by adjusting the rate of nitrogen supply, or it was restricted by addition of 0.5 μM abscisic acid (ABA). Another approach used to investigate the specific roles of nitrogen (N) and phosphorus (P), was to transfer optimally growing plants to media without N or P but otherwise complete. The plants were harvested at regular intervals for determination of the RGR and levels of cytokinins of the isopentenyladenosine (iPA) and zeatinriboside (ZR) types with an enzyme-linked immunosorbent assay (ELISA). Levels of both iPA- and ZR-type cytokinins decreased when nitrogen was applied to cultures in growth limiting amounts. The cytokinin levels decreased more rapidly than the RGR when either N or P was lacking in the medium, suggesting an early influence of nutrient availability on cytokinin levels which in turn may induce adaptive response by the plant. RGR retardation induced by ABA did not affect cytokinin levels during the first 4 days of the treatment, and the later effects were small. The experiments gave no indication that ABA is involved in the adaptation response of Lemna plants to nutritional stress.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00027445
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    Studies on decomposition ofCeratophyllum demersum litter under laboratory and field conditions: losses of dry mass and nutrients, qualitative changes in organic compounds and consequences for ambient water and sediments (1990)
    Springer
    Hydrobiologia 194 (1990), S. 91-114 
    Details
    ISSN: 1573-5117
    Keywords: submerged macrophyte ; Ceratophyllum demersum ; litter ; decomposition ; pyrolysis mass spectra ; residual mass ; carbon ; nitrogen ; phosphorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A study was made of decomposition ofCeratophyllum demersum litter over a 17-day period under controlled conditions of temperature and oxygen (5, 10 and 18 °C; aerobic and anaerobic) and over a 169-day period in the field (Lake Vechten, The Netherlands). Litter, water and sediment were sampled on the 0, 2, 4, 7 and 17th day under controlled conditions and on the 0, 17, 49, 127 and 169th day in the field. The litter was analyzed quantitatively for dry mass, ash, carbon, nitrogen, phosphorus and qualitatively of organic composition by pyrolysis mass spectrometry. The water was analyzed for the elemental concentrations of organic carbon (total and dissolved), nitrogen (total, ammonia and particulate) and phosphorus (total and orthophosphate) and for the concentrations of photosynthetic pigments and bacteria. The sediment was analyzed for the elemental concentrations of nitrogen, carbon and phosphorus, and for bacterial numbers. The pattern of litter mass loss fitted an exponential model fairly well. Mass decreased faster under controlled aerobic than under anaerobic conditions and the decrease was stimulated by increasing temperature, relatively more in the range of 5 to 10 °C (by 20%) than in the range of 10 of 18 °C (by 2%). The residual mass ranged from 73 to 43% of initial under controlled aerobic conditions and from 84 to 65% under anaerobic conditions after 17 days. It decreased far less in the field, to 38% of initial mass in the field after 169 days. The litter initially lost a carbohydrate fraction by leaching in all treatments. The protein content decreased initially as well but increased subsequently at increasing temperature stimulated under anaerobic conditions. The changes in organic composition were correlated with those in nitrogen but not with those in carbon and phosphorus contents. The organic composition of litter incubated in the field differed from that of litter incubated in the laboratory. The field residues contained less proteinaceous material than the laboratory residues. The changes in carbon, nitrogen and phosphorus concentrations in the litter showed different patterns. The carbon concentration generally increased, the nitrogen concentration initially dropped and increased subsequently, and the phosphorus concentration initially dropped and remained relatively constant subsequently. Chemical immobilization of the decomposition process may have occurred in the laboratory, but was unlikely in the field. Carbon, nitrogen and phosphorus left the litter initially largely in particulate form and were recovered in the water. The ratio dissolved: total nutrient concentration was lower under controlled aerobic than under anaerobic conditions. Increasing temperature stimulated bacterial use of dissolved organic carbon and nitrogen. A rapid nutrient flow occurred from macrophyte litter, via water to sediment. The phytoplankton biomass in the water was greatly stimulated by substances freed from the decomposing litter. Diatoms increased generally relatively more than green algae, predominating alternatively with green algae under aerobic conditions and continuously under anaerobic conditions. Bacterial numbers in the water initially increased, partly due to transgression of bacteria from the sediment-water interface to the water and partly due to an actual increase in community biomass. The bacteria returned largely to the sediment-water interface, stimulated by increasing temperature, as most of the substrate readily usable by them had left the litter in the litter-bag and was associated with the upper sediment layers. It is feasible that the annual die-off of theC. demersum population of Lake Vechten barely affects nutrient cycling in the lake, because the contribution to the nutrient pools of the lake when fully mixed is only small. However, small particles originating from decomposingC. demersum litter may influence the lake considerably by decreasing water transparency and serving as a food source for filter-feeders and detritivorous macrofauna.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00028411
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    Gull contributions of phosphorus and nitrogen to a Cape Cod kettle pond (1990)
    Springer
    Hydrobiologia 202 (1990), S. 61-69 
    Details
    ISSN: 1573-5117
    Keywords: Gulls ; phosphorus ; nitrogen ; eutrophication ; excretion ; nutrients
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Nutrient excretion rates and the annual contribution of P from the feces of the gulls Larus argentatus and L. marinus (and of N from L. argentatus) to the nutrient budget of Gull Pond (Wellfleet), a soft water seepage lake, have been estimated. Intensive year-round gull counts by species were combined with determinations of defecation rate and the nutrient content of feces to quantitatively assess the P loading rates associated with regular gull use of this coastal pond on a seasonal and annual basis. Total P loading from gulls was estimated to be 52 kg yr−1, with 17 kg from L. argentatus and 35 kg from L. marinus, resulting from about 5.0 × 106 h yr−1 and 1.7 × 106 h yr−1 of pond use. This compares with P loading estimates of 67 kg yr−1 from upgradient septic systems, 2 kg yr−1 from precipitation and 3 kg yr−1 from unpolluted ground water. Fifty-six percent of annual gull P loading was associated with migratory activity in late fall. Estimated annual N loading by L. argentatus was 14 kg TKN, 206 g NO3-N, and 1.85 g g NH3-N.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00027092
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    Development and application of a technique for estimating nutrient deficiency in soft sediments (1990)
    Springer
    Hydrobiologia 203 (1990), S. 93-97 
    Details
    ISSN: 1573-5117
    Keywords: sediments ; nitrogen ; phosphorus ; nutrient limitation ; photosynthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A diffusion enrichment technique is presented which allows for chemical enrichment of soft surficial and shallow subsurface sediments and subsequent measurement of O2 production. The sediment is enriched by inserting a perforated tube containing dialysis tubing filled with a nutrient/agar mixture. O2 production by surficial sediment is measured using an inverted, translucent, polyethylene chamber over the sediment. The inside of the chamber contains a collapsible bag connected to the water outside the chamber. When water overlying the sediment is withdrawn from a sampling port, it is displaced with water from outside the chamber, thus preventing contamination of water samples with pore water from below. The technique was tested by enriching near-shore sediments in a large oligotrophic lake with inorganic N and P. NHinf4/p+ additions significantly stimulated benthic primary production as measured by 02 production, whereas enrichment with POinf4/3- had no effect.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00005617
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    Effects of mixing and silica enrichment on phytoplankton seasonal succession (1991)
    Springer
    Hydrobiologia 210 (1991), S. 171-181 
    Details
    ISSN: 1573-5117
    Keywords: phytoplankton ; succession ; mixing ; silica ; enrichment ; nutrients ; nitrogen ; phosphorus ; carbon ; carbon dioxide ; bicarbonate ; light ; transparency ; cryptophytes ; diatoms ; blue green algae ; cyanophytes ; dinoflagellates ; greens ; dominance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract During the summer of 1983, cryptophytes, diatoms, cyanophytes, and the dinoflagellate, Ceratium hirundinella were most prominant among the phytoplankton of Eau Galle Reservoir. In the open water, cryptophytes and diatoms peaked in the spring, cyanophytes were most successful in the early summer, and Ceratium was dominant from mid-July until early August. In general, the sequence of events corresponded quite closely to the model of seasonal succession developed by the Plankton Ecology Group of the International Society of Limnology. To a large extent, the same pattern held in four experimental water columns. Departures from the model involved the roles of specific nutrients in diatom and cyanophyte periodicity. Diatoms began to yield to cyanophytes in late spring despite intermittent mixing and silica enrichment. Although capable of buoyancy regulation and thus well adapted to stable water columns, cyanophytes had greater increases in biomass in mixed columns, and in those columns, were most successful during a period of intermittent mixing. Cyanophyte success varied inversely with TN : TP ratios during the period of intermittent mixing, but not subsequently. By mid-July, Ceratium dominated the phytoplankton of every column except that of a mixed column in which conditions favored cyanophytes and large diatom species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00034675
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    A comparative study of heavy metal contamination and pollution in four reservoirs in the English Midlands, UK (1991)
    Springer
    Hydrobiologia 214 (1991), S. 155-162 
    Details
    ISSN: 1573-5117
    Keywords: urbanisation ; heavy metals ; phosphorus ; macrofossils ; lake and fluvial sediments ; lake rehabilitation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Chemical and palaeoecological analysis of lake and fluvial sediments reveals a range of human impact on the sediment chemistry of four reservoirs in the English Midlands. Atmospheric pollution is recorded in both inner city and rural sites over the last 150 years. Catchment derived heavy metals at one urban site reveals high contamination factors for Pb, Cu, Ni, Zn and Cd. From the phosphorus record and from reconstructions based on macrofossil remains, eutrophication is recorded at all sites. Recent attempts to evaluate rehabilitation programmes for the inner city sites have proved problematical owing to two major problems. First, their shallow nature results in a high cost of desilting and, secondly, heavy metal contamination makes treatment and disposal of the sediment expensive.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00050945
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    The effects of dredging and fish stocking on the trophic status of shallow, peaty ditches (1992)
    Springer
    Hydrobiologia 233 (1992), S. 225-233 
    Details
    ISSN: 1573-5117
    Keywords: ditches ; fish stock ; dredging ; biomanipulation ; eutrophication ; phosphorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In the polder ‘Wormer, Jisp and Nek’, which forms part of a grossly eutrophicated region in the province North Holland, the effects of dredging and biomanipulation were studied in ditches. Four areas, including 5.7 ha surface water in total, were dammed up and dredged. It was feasible to remove the loose top-layer of sediments with a high content of phosphorus by modifications of the dredging machine. In two areas the fish stock was managed. The measures resulted in an improvement of the water quality: an increase of the transparency and a decrease of suspended solids, phosphorus, nitrogen and algae. The chlorophyll-a concentration decreased nearly to 100 µg l−1 (summer average). The relative densities of diatoms, green algae and cyanobacteria did not change. The zooplankton community was dominated by small rotifers and crustaceans both before and after restoration measures. Cladocerans were scarcely present. In the second year after the measures, submerged macrophytes developed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00016111
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    Effects of phytoplankton on the elemental composition (C, N, P) of suspended particulate material in the lower river Rhine (1992)
    Springer
    Hydrobiologia 235-236 (1992), S. 479-489 
    Details
    ISSN: 1573-5117
    Keywords: River Rhine ; phytoplankton ; suspended material ; carbon ; nitrogen ; phosphorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The spatial and temporal distribution of element concentrations were monitored together with chlorophyll a as an indicator of algal density to assess the effect of phytoplankton on the elemental composition (C, N, P) of suspended materials in the lower Rhine. The high concentrations of particulate C, N and P in the river were found to decrease in the delta and to increase again in the estuarine turbidity zone. Phytoplankton blooms increased the concentrations of particulate C, N, and P significantly in the upstream part of the river. In summer 1989, 15–65% of the particulate C and 20–75% of the particulate N were attributable to phytoplankton. Together with published data these observations indicate that in eutrophic rivers, the input of organic materials from the catchment is strongly modified and supplemented by in situ growth of phytoplankton. During seaward transport the phytoplankton and the particulate elements disappeared from the river water concomitantly with the suspended matter, indicating an increased retention of these elements due to sedimentation. In contrast, soluble ammonia, nitrite and phosphate increased in the tidal reaches of the river because of local input in the harbour and city of Rotterdam and because of mineralization. Therefore the total nutrient load of the Rhine estimated at the German/Dutch border does not reflect the actual input into the sea.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00026236
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    Detritus and nutrient dynamics in the shore zone of lakes: a review (1993)
    Springer
    Hydrobiologia 251 (1993), S. 49-58 
    Details
    ISSN: 1573-5117
    Keywords: lake littoral ; detritus ; macrophytes ; decomposition ; nitrogen ; phosphorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The importance of detritus varies greatly among shore zones of lakes, but in a large majority of these regions detrital pathways prevail. Aside from a great spatial and seasonal variability, macrophytes and bottom sediments appear to be dominant stores of nutrients in these habitats. Macrophytes hold a central position in nutrient cycling in the shore-littoral lake zones. They are the main source of autochthonous detritus as they prevail in the total biomass of littoral organisms, and they are only rarely available as direct food of consumers. Various processes and interactions determine the role of macrophytes in nutrients dynamics. These are: the intensity of nutrient uptake and translocation, release of nutrients by healthy plants and from decomposing plants, exchange of elements between macrophytes and their periphyton, as well as interception of seston by macrophyte stands. Particular plant species differ in their time of dying and susceptibility to decomposition. The changes in decomposing material (size structure of particles and nutrient content) mean that detritus in various stages of decomposition differs in its role in trophic dynamics of shore-littoral lake zones. Several types of shore regions as regards detritus sources and retention level are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00007164
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    Frost formation in the ecotonal zone and its role for release of nutrients (1993)
    Springer
    Hydrobiologia 251 (1993), S. 65-72 
    Details
    ISSN: 1573-5117
    Keywords: Frozen littoral ; frost heave ; nutrient release ; nitrogen ; phosphorus ; calcium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In winter, the littoral substrate of ecotonal zones along north Swedish rivers and lakes freezes. Even if the littoral is flooded at freeze-up, the ice freezes solid to the shore substrate due to low temperature combined with a gradual decrease in water level during winter. Frost conditions were studied during an 8-year period along eight littoral transects in the River Vindelälven and adjacent riverside lagoons. Heavy frost heave with formation of needle ice was observed in several places. Nutrient release was suggested to take place due to the frost process. Sediment was taken to a laboratory experiment where samples with sediment and water were kept under unfrozen and frozen conditions during six months. N (total-N) and Ca were significantly released to the water, while P (total-P) did not show any clear movement from the frozen sediment. The results indicate that frost processes in ecotonal zones are involved in the movement of nutrients between sediment and water.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00007166
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    Microbial decomposition of freshwater macrophytes in the littoral zone of lakes (1993)
    Springer
    Hydrobiologia 251 (1993), S. 59-64 
    Details
    ISSN: 1573-5117
    Keywords: decomposition ; macrophytes ; microorganisms ; weight loss ; phosphorus ; littoral
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The decomposition of several lake macrophytes was investigated under field conditions. Data on weight and phosphorus loss, numbers of microbial decomposers and their activity were obtained. Experiments were conducted in the littoral of two lakes with different levels of macrophyte development. Weight loss during 40–60 days of decomposition for fast-decomposing plants was 60–95% and after 365-day of incubation, Potamogeton perfoliatus L. lost nearly 100% of its initial weight. Slow-decomposing plants lost 20–50% of their initial weight after 40–60 days of incubation, and Phragmites australis (Cav.) Trin. ex Steud. lost 84% of its initial weight after 365 days. Total phosphorus content in plants did not decrease at the first stages of decomposition. The number of microbial decomposers utilizing both labile and resistant substrates increased 2–6 times during the first 5–25 days period. During this period the community was morphologically diverse and biochemically active (high level of microbial respiration). It coincided with the highest weight loss. After that period, the number of microorganisms utilizing labile substrates, as well as the rate of decomposition decreased. The part of macrophyte organic matter entering the biological cycle in two lakes made up 3.5% and 26% of phytoplankton primary production. Bacterial production on decomposing macrophytes was calculated at 4% and 51% of bacterioplankton production, respectively, in both lakes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00007165
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    Drainage history and land use pattern of a Swedish river system — their importance for understanding nitrogen and phosphorus load (1993)
    Springer
    Hydrobiologia 251 (1993), S. 285-296 
    Details
    ISSN: 1573-5117
    Keywords: land drainage ; nitrogen ; phosphorus ; areal coefficients ; agricultural streams ; riparian ecotones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract During the 19th and the first half of the 20th century, approximately 300 km2 of lakes and wetlands, representing 29% of the River Kavlingean catchment in Southern Sweden, were drained to make land available for agriculture. Published accounts of nutrient loads from the catchment indicated that until the mid 20th century, factories and urban point sources were the major contributors of both nitrogen and phosphorus. By the middle of the 20th century, the construction of sewage treatment plants had effectively reduced phosphorus pollution. Concurrently, the land drained in the previous century underwent a more intense cultivation, with productivity being maintained by commercial fertilizers. Subsequently, net nutrient loads from agriculture continued to increase, reaching an annual load of 2652 tons total-nitrogen and 70 tons total-phosphorus for the River Kävlingeån. Whilst high nutrient leakage from agricultural watersheds may be a problem which is only recently recognized, it had its origins in nearly a hundred years of commonly accepted agricultural policy. To assess the importance of agriculture as the major source of nutrients to the River Kävlingeån system, three tributary catchment areas, differing in terms of their land use patterns (high, medium and low intensity of agricultural use), were studied and compared with literature figures. Results indicated that agricultural nutrient loss areal coefficients were substantially higher than the literature figures, demonstrating the role of agriculture as source of nutrients to the River Kävlingeån system. The agricultural land use policies of the last fifty years were revealed to be most important with regard to this role. Of such land use policies, the cultivation of the last 10–15% of land employed for agricultural use (primarily riparian ecotones) may be of most significance. The literature indicates that intense agricultural use of this final 10–15% may account for a ca. 50% increase in nitrogen loss. This suggests that one solution to the problem of agricultural diffuse pollution may lie in the restoration and sustainable management of riparian ecotones of agricultural streams.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00007188
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    Extracellular phosphatase activity in sediments of the Breitenbach, a Central European mountain stream (1993)
    Springer
    Hydrobiologia 253 (1993), S. 207-216 
    Details
    ISSN: 1573-5117
    Keywords: stream ; sandy sediment ; phosphorus ; extracellular enzymes ; phosphatase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Activity of extracellular phosphatases (phosphomonoesterases) was measured in sandy streambed sediments of the Breitenbach, a small unpolluted upland stream in Central Germany. Fluorigenic 4-methylumbelliferyl phosphate served as a model substrate. Experiments were conducted using sediment cores in a laboratory simulation of diffuse groundwater discharge through the stream bed, a natural process occurring in the Breitenbach as well as many other streams. Streambed sediments contained high levels of particulate phosphorus, but concentrations of dissolved phosphorus in the interstitial water were 3 to 4 orders of magnitude lower. These interstitial concentrations were similar to those in the stream and groundwater. Extracellular phosphatase activity was high in the streambed sediments. These enzymes probably contribute significantly to the flux of phosphorus in sediment by hydrolyzing phosphomonoesters, making free phosphate available to the sediment microorganisms. Factors influencing the kinetic parameters V max (maximum activity) and apparent K m (enzyme affinity) of phosphatase were discharge rates of water through the sediment, water quality (ground- or stream water), and substrate (phosphomonoesters) as well as dissolved ortho-phosphate concentrations. Enzymes are supposed to be effective at limiting substrate concentrations, where, in this study, changes in discharge rates had little influence on rates of hydrolysis. Higher V max and lower K m values were found during percolation of groundwater through the sediment cores, compared with stream water. This indicates that rates of hydrolysis were higher with groundwater, both at substrate limitation and at substrate saturation. This was probably a consequence of the lower levels of dissolved ortho-phosphate in the groundwater.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00050739
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    The effect of deposition of organic matter on phosphorus dynamics in experimental marine sediment systems (1993)
    Springer
    Hydrobiologia 253 (1993), S. 83-98 
    Details
    ISSN: 1573-5117
    Keywords: organic matter ; phosphorus ; sandy marine sediment ; macrofauna ; boxcosms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of deposition of organic matter on phosphorus dynamics in sandy marine sediments was evaluated using an experimental system (boxcosms) and three different strategies: (1) no supply (2) one single addition (3) weekly additions of a suspension of algal cells (Phaeocystis spec.). Macrofauna (3 species, 6 individuals of each) were added to half of the boxes. Both in the case of the single and weekly additions a clear effect of increased organic matter loading on phosphorus dynamics was found. Following the organic matter addition, porewater phosphate concentrations in the upper sediment layer increased, phosphate release rates from the sediment increased by a factor 3–5 and in the boxes to which a single addition was applied NaOH-extractable phosphorus increased substantially. The increase in phosphate release rates from the sediment was attributed to mineralization of the added material and to direct release from the algal cells. No clear effect of the presence of macrofauna on sediment-water exchange of phosphate could be discovered. The macrofauna were very effective at reworking the sediment, however, as illustrated by the organic carbon profiles. It is hypothesized that the sediment-water exchange rates of phosphate were regulated by the layer of algal material which was present on the sediment surface in the fed boxes. In the boxes to which the single addition was applied porewater phosphate concentrations were lower and NaOH-extractable phosphorus was higher in the presence of macrofauna, suggesting that macrofauna can stimulate phosphate binding in the sediment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00050724
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    The role of microorganisms in mobilization and fixation of phosphorus in sediments (1993)
    Springer
    Hydrobiologia 253 (1993), S. 103-121 
    Details
    ISSN: 1573-5117
    Keywords: bacteria ; phosphorus ; phosphorus cycling in lakes ; sediments
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cycling of phosphorus (P) at the sediment/water interface is generally considered to be an abiotic process. Sediment bacteria are assumed to play only an indirect role by accelerating the transfer of electron from electron donors to electron acceptors, thus providing the necessary conditions for redox-and pH-dependent, abiotic sorption/desorption or precipitation/dissolution reactions. Results summarized in this review suggest that (1) in eutrophic lakes, sediment bacteria contain as much P as settles with organic detritus during one year (2) in oligotrophic lakes, P incorporated in benthic bacterial biomass may exceed the yearly deposition of bioavailable P several times (3) storage and release of P by sediment bacteria are redox-dependent processes (4) an appreciable amount of P buried in the sediment is associated with the organic fraction (5) sediment bacteria not only regenerate PO4, they also contribute to the production of refractory, organic P compounds, and (6) in oligotrophic lakes, a larger fraction of the P settled with organic detritus is converted to refractory organic compounds by benthic microorganisms than in eutrophic lakes. From this we conclude that benthic bacteria do more than just mineralize organic P compounds. Especially in oligotrophic lakes, they also may regulate the flux of P across the sediment/water interface and contribute to its terminal burial by the production of refractory organic P compounds.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00050731
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    The role of Gloeotrichia echinulata in the transfer of phosphorus from sediments to water in Lake Erken (1993)
    Springer
    Hydrobiologia 253 (1993), S. 123-129 
    Details
    ISSN: 1573-5117
    Keywords: phosphorus ; cyanobacteria ; Gloeotrichia echinulata ; sediment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The abundance of Gloeotrichia echinulata colonies in the sediments of Lake Erken and their phosphorus content were investigated to determine the contribution of Gloeotrichia colonies to total sediment phosphorus. Moreover, the potential size of the algal inoculum and the migration to the water during summer were estimated. The surplus phosphorus content of the resting colonies in the sediment was about 45% of total phosphorus, which maximized at 8.5 µg P (mg dw)−1 or 81 ng P colony−1. The C:P ratio (by weight) in the early colonies appearing in the lake water was 50:1, while the ratio stabilized at 150 during the major migration period. The internal supply of surplus phosphorus was used during the pelagic growth of the colonies. The internal phosphorus loading to the epilimnion of Lake Erken due to Gloeotrichia migration could, from the measurements of the increase in particulate epilimnetic phosphorus, be estimated at 40 mg P m −2 or 2.5 mg P m−2 d−1 in late July and early August. Determination of the number of colonies in the sediment before and during the migration verified this value to be a conservative estimate of the internal phosphorus loading due to Gloeotrichia migration to the epilimnion in Lake Erken. The sediment P content calculated from the P concentration in early epilimnion colonies resulted in a value of 35 µg P (g dw)−1 as a maximum. This corresponds to only 3% of the total phosphorus content in Lake Erken sediment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00050732
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    The effect of herbivorous crustacean zooplankton on epilimnetic carbon and phosphorus cycling (1993)
    Springer
    Hydrobiologia 254 (1993), S. 21-34 
    Details
    ISSN: 1573-5117
    Keywords: biomanipulation ; microcosms ; carbon cycle ; phosphorus ; primary production ; sedimentation ; plankton
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Plastic limnocorrals (LCs; volume 70 m3) in oligo-mesotrophic Lake Lucerne, Switzerland were used to manipulate planktonic communities by (1) removing large zooplankton at the start of the experiment, and (2) adding phosphate during experiments of two weeks duration. Primary production (14C-assimilation), chlorophyll, standing crops and sedimentation of particulate organic carbon (POC) and of particulate phosphorus, as well as plankton composition were assessed simultaneously in two to four differently treated LCs. Carbon and phosphorus mass balances were calculated from assimilation, temporal change in standing crop of particulate matter, and sedimentation. A quick elimination of crustaceans by screening hardly increased primary production, but decreased sedimentation and mineralisation of particulate organic carbon, and thus significantly enhanced the standing crop of POC, but decreased POC turnover. The exclusion of crustaceans increased the mean residence time of total phosphorus by a reduced P loss by sedimentation. Increased grazing pressure during the experiment showed little grazing induced effect on plankton composition and primary production except at the very end. We conclude that in an oligo-mesotrophic lake, buffering mechanisms attenuate the impact of changing grazing pressures on primary production.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00007762
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    The third international workshop on phosphorus in sediments (1993)
    Springer
    Hydrobiologia 253 (1993), S. xi 
    Details
    ISSN: 1573-5117
    Keywords: phosphorus ; sediments ; chemistry ; microbiology ; modelling ; lake restoration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00050717
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    Transport and retention of matter in riparian ecotones (1993)
    Springer
    Hydrobiologia 251 (1993), S. 95-101 
    Details
    ISSN: 1573-5117
    Keywords: Land/stream ecotones ; bank runoff ; aerial drift ; retention ; carbon ; nitrogen ; phosphorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The ‘stream’ ecosystem is described as a three-layered system, vertically as well as horizontally. The land/stream ecotone is defined as the area where lotic and edaphic characters overlap at the time of observation. The study site — ‘Oberer Seebach’, near the Biological Station Lunz — and the methods employed are described. Only a surprisingly small fraction (less than 10 %) of total imports is transported across the surface ecotones. The driving variables determining bank runoff and aerial drift are described and discussed. The importance of channel areas which are periodically flooded is stressed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00007169
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...