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
  • 1995-1999
  • 1990-1994  (15)
  • 1980-1984  (15)
  • 1992  (15)
  • 1980  (15)
  • 1
    Electronic Resource
    Electronic Resource
    Stomatal response to environment and a possible interrelation between stomatal effects on transpiration and CO2 assimilation (1980)
    Oxford, UK : Blackwell Publishing Ltd
    Plant, cell & environment 3 (1980), S. 0 
    Details
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Abstract It had been hypothesized that if daily CO2 assimilation is to be maximized at a given level of daily transpiration, stomatal apertures should change during the day so that the gain ratio (∂A/∂g)/(∂E/∂g) remains constant. These partial differentials describe the sensitivity of assimilation rate (A) and transpiration rate (E) to changes in stomatal conductance (g). Experiments were conducted to determine whether stomata respond to environment in a manner which results in constant gain ratios.Gas–exchange measurements were made of the stomatal and photosynthetic responses of Vigna unguiculata L. Walp. in controlled environments. Leaf conductance to water vapour responded to step changes in temperature and humidity so that for different steady-state conditions the gain ratio remained constant on all but one day. Depletion of water in the root zone resulted in day-to-day increases in gain ratio which were correlated with decreases in maximum leaf conductance to water vapour. The significance of the results for plant adaptation and stomatal mechanisms, and methods for measuring the gain ratio, are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/1365-3040.ep11587040
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Stomatal response to drying soil in relation to changes in the xylem sap composition of Helianthus annuus. I. The concentration of cations, anions, amino acids in, and pH of, the xylem sap (1992)
    Oxford, UK : Blackwell Publishing Ltd
    Plant, cell & environment 15 (1992), S. 0 
    Details
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Sunflower plants (Helianthus annuus L.) were subjected to soil drying with their shoots either kept fully turgid using a Passioura-type pressure chamber or allowed to decrease in water potential. Whether the shoots were kept turgid or not, leaf conductance decreased below a certain soil water content. During the soil drying, xylem sap samples were taken from individual intact and transpiring plants. Xylem sap concentrations of nitrate and phosphate decreased with soil water content, whereas the concentrations of the other anions (SO42 and Cl−) remained unaltered. Calcium concentrations also decreased. Potassium, magnesium, manganese and sodium concentrations stayed constant during soil drying. In contrast, the pH, the buffering capacity at a pH below 5 and the cation/anion ratio increased after soil water content was lowered below a certain threshold. Amino acid concentration of the xylem sap increased with decreasing soil water content. The effect of changes in ion concentrations in the xylem sap on leaf conductance is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-3040.1992.tb01488.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Stomatal response to drying soil in relation to changes in the xylem sap composition of Helianthus annuus. II. Stomatal sensitivity to abscisic acid imported from the xylem sap (1992)
    Oxford, UK : Blackwell Publishing Ltd
    Plant, cell & environment 15 (1992), S. 0 
    Details
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Sunflower plants [Helianthus annuus L.) were subjected to soil drought. Leaf conductance declined with soil water content even when the shoot was kept turgid throughout the drying period. The concentration of abscisic acid in the xylem sap increased with decreasing soil water content. No general relation could be established between abscisic acid concentration in the xylem sap and leaf conductance due to marked differences in the sensitivity of leaf conductance of individual plants to abscisic acid from the xylem sap. The combination of these results with data from Gollan, Schurr & Schulze (1992, see pp. 551–559, this issue) reveals close connection of the effectiveness of abscisic acid as a root to shoot signal to the nutritional status of the plant.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-3040.1992.tb01489.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Ökophysiologische Untersuchungen an Pflanzen der Namib-Wüste (1980)
    Springer
    Naturwissenschaften 67 (1980), S. 21-28 
    Details
    ISSN: 1432-1904
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Natural Sciences in General
    Notes: Abstract The southern Namib desert has a vegetation cover of mainly succulent plants in which species of the Mesembryanthemaceae are predominant. Climatically this area is characterized by hot and dry days, and cool and humid nights with episodic rainfalls only in winter. In this environment a great number of species perform a crassulaceaen acid metabolism (CAM). The responses of these plants to water stress as well as the regulation of CAM in the natural habitat are described and discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00424499
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Leaf temperatures and energy balance ofWelwitschia mirabilis in its natural habitat (1980)
    Springer
    Oecologia 44 (1980), S. 258-262 
    Details
    ISSN: 1432-1939
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Welwitschia mirabilis is a perennial desert plant with extremely large leaves (0.5–1.0 m broad, 1–2 m long). Leaf temperatures were measured in the field and the energy budget was calculated. The portions of the leaf which were kept above the ground had leaf temperatures which were only 4–6°C above air temperature. In the leaf portions which were in contact with the ground leaf temperatures were 6–12°C above air temperature (absolute maximum 51°C). The important feature in the energy budget ofWelwitschia mirabilis is its high reflectivity (38% of the global radiation). Only about 56% of the global radiation is absorbed by the thick leathery leaves. The energy loss due to convection is of the same order of magnitude as the reflection and it is abouy the same in the portions of leaf on and above the ground. The difference in leaf temperatures found in these portions is due to the loss of thermal radiation from the section of leaf above the ground to the cooler ground which is shaded by the leaf. The provision of a heat sink due to the large area of shade cast by these large leaves is of significance to the existence ofWelwitschia mirabilis in its arid habitats.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00572688
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Long-term effects of drought on wild and cultivated plants in the Negev desert (1980)
    Springer
    Oecologia 45 (1980), S. 11-18 
    Details
    ISSN: 1432-1939
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The relation between daily maximal rates of net photosynthesis and plant water status was studied during a dry season on irrigated and non-irrigated, naturally growing, perennial wild plants. Species were examined which differ in phenology, leaf anatomy and morphology: Hammada scoparia, Artemisia herba-alba, Zygophyllum dumosum, and Reaumuria negevensis. Prumus armeniaca which was growing in the run-off farm at Avdat and which has mosomorphic leaves was included in the comparison. All plants differed in their seasonal change in plant water status, and in their seasonal change in daily maximal net photosynthesis. Rates of CO2 uptake were not uniquely related to simultanously measured leaf water potentials. Daily maximal rates of net photosynthesis of non-irrigated plants, and the difference between maximal CO2 uptake of irrigated and non-irrigated plants were examined in relation to pre-dawn water potential. Maximal net photosynthesis rates decreased very rapidly with decrease in pre-dawn water potential or, for Hammada scoparia, they decreased even with a constant level of pre-dawn water potential. Consequently, it was considered necessary to include both time and water potential in a parameter “bar day” describing the accumulated drought stress of the plants. All species showed the same relation between relative maximal net photosynthesis and drought experience as determined by cumulative daily addition of pre-dawn water potentials for the non-irrigated plants since the last rain.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00346700
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Long-term effects of drought on wild and cultivated plants in the Negev desert (1980)
    Springer
    Oecologia 45 (1980), S. 19-25 
    Details
    ISSN: 1432-1939
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The seasonal change in diurnal patterns of net photosynthesis and daily carbon gain is studied in relation to the plant water status of the irrigated and non-irrigated naturally growing desert species Hammada scoparia, Zygophyllum dumosum, Artemisia herba-alba and Reaumuria negevensis. Comparison is made to cultivated Prunus armeniaca. Under non-irrigated natural conditions Hammada scoparia, a C4 plant, showed one-peaked flat diurnal courses of CO2 uptake which changed into a pattern of a high morning peak of CO2 uptake or slightly two-speaked curves in the late dry season. In contrast, the C3 species Zygophyllum dumosum, Artemisia herba-alba and Prunus armeniaca changed from one-peaked to distinct two-peaked patterns. At the end of the dry season, non-irrigated plants showed respiration only. Reaumuria negevensis had one-peaked curves with a low level of CO2 uptake. There is no general relation between day-time CO2 gain and pre-dawn water potential for the investigated species. In order to characterize the effect of soil drought, the CO2 gain during day-time of non-irrigated plants is expressed as a percentage of the CO2 gain of the irrigated counterparts. After an initial period of minimal drought effect, the relative day-time CO2 gain decreases almost linearly with cumulative water stress as determined by the daily addition of pre-dawn water potentials for the non-irrigated plants since the last rainfall. The slope of decrease differs from species to species. The relation of daily CO2 gain to maximal net photosynthesis is discussed. Initially, at a good plant water status, the daily CO2 gain does not decrease in proportion to the maximal photosynthetic rates as a result of stomatal control at high photosynthetic activity. At increasing water stress the daily CO2 gain decreases more than proportionally to the decrease of the maximal rates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00346701
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Transpiration and canopy conductance in a pristine broad-leaved forest of Nothofagus: an analysis of xylem sap flow and eddy correlation measurements (1992)
    Springer
    Oecologia 91 (1992), S. 350-359 
    Details
    ISSN: 1432-1939
    Keywords: Canopy conductance ; Canopy transpiration ; Xylem sap flow ; Humidity response of stomatal ; Nothofagus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Tree transpiration was determined by xylem sap flow and eddy correlation measurements in a temperate broad-leaved forest of Nothofagus in New Zealand (tree height: up to 36 m, one-sided leaf area index: 7). Measurements were carried out on a plot which had similar stem circumference and basal area per ground area as the stand. Plot sap flux density agreed with tree canopy transpiration rate determined by the difference between above-canopy eddy correlation and forest floor lysimeter evaporation measurements. Daily sap flux varied by an order of magnitude among trees (2 to 87 kg day−1 tree−1). Over 50% of plot sap flux density originated from 3 of 14 trees which emerged 2 to 5 m above the canopy. Maximum tree transpiration rate was significantly correlated with tree height, stem sapwood area, and stem circumference. Use of water stored in the trees was minimal. It is estimated that during growth and crown development, Nothofagus allocates about 0.06 m of circumference of main tree trunk or 0.01 m2 of sapwood per kg of water transpired over one hour. Maximum total conductance for water vapour transfer (including canopy and aerodynamic conductance) of emergent trees, calculated from sap flux density and humidity measurements, was 9.5 mm s−1 that is equivalent to 112 mmol m−2 s−1 at the scale of the leaf. Artificially illuminated shoots measured in the stand with gas exchange chambers had maximum stomatal conductances of 280 mmol m−2 s−1 at the top and 150 mmol m−2 s−1 at the bottom of the canopy. The difference between canopy and leaf-level measurements is discussed with respect to effects of transpiration on humidity within the canopy. Maximum total conductance was significantly correlated with leaf nitrogen content. Mean carbon isotope ratio was −27.76±0.27‰ (average ±s.e.) indicating a moist environment. The effects of interactions between the canopy and the atmosphere on forest water use dynamics are shown by a fourfold variation in coupling of the tree canopy air saturation deficit to that of the overhead atmosphere on a typical fine day due to changes in stomatal conductance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00317623
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    The effect of nitrogen nutrition on growth and biomass partitioning of annual plants originating from habitats of different nitrogen availability (1992)
    Springer
    Oecologia 92 (1992), S. 236-241 
    Details
    ISSN: 1432-1939
    Keywords: Annual plants ; Biomass partitioning ; Nitrogen nutrition ; Relative growth rate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The hypothesis was tested that faster growth of nitrophilic plants at high nitrogen (N) nutrition is counterbalanced by faster growth of non-nitrophilic plants at low N-nutrition. Ten annual plant species were used which originated from habitats of different N-availability. The species' preference for N was quantified by the “N-number” of Ellenberg (1979), a relative measure of nitrophily. The plants were cultivated in a growth cabinet at five levels of ammonium-nitrate supply. At low N-supply, the relative growth rate (RGR) was independent of nitrophily. At high N-supply, RGR tended to be higher in nitrophilic than in non-nitrophilic species. However, the response of RGR to N-supply was strongly and positively correlated with the nitrophily of species. Increasing N-supply enhanced partitioning to leaf weight per total biomass (LWR) and increased plant leaf area per total biomass (LAR). Specific leaf weight (SLW) and LWR were both higher in non-nitrophilic than in nitrophilic species at all levels of N-nutrition. NAR (growth per leaf area or net assimilation rate) increased with nitrophily only under conditions of high N-supply. RGR correlated positively with LAR, irrespective of N-nutrition. Under conditions of high N-supply RGR correlated with SLW negatively and with NAR positively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00317370
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Decreased ribulose-1,5-bisphosphate carboxylase-oxygenase in transgenic tobacco transformed with “antisense” rbcS (1992)
    Springer
    Planta 188 (1992), S. 522-531 
    Details
    ISSN: 1432-2048
    Keywords: Nicotiana (photosynthesis) ; Nitrogen ; Photosynthesis (control analysis) ; Ribulose-1,5-bisphosphate carboxylase-oxygenase ; Transgenic plant
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of nitrogen supply during growth on the contribution of ribulose-1,5-bisphosphate carboxylase-oxygenase (Rubisco; EC 4.1.1.39) to the control of photosynthesis was examined in tobacco (Nicotiana tabacum L.). Transgenic plants transformed with antisense rbcS to produce a series of plants with a progressive decrease in the amount of Rubisco were used to allow the calculation of the flux-control coefficient of Rubisco for photosynthesis (CR). Several points emerged from the data: (i) The strength of Rubisco control of photosynthesis, as measured by CR, was altered by changes in the short-term environmental conditions. Generally, CR was increased in conditions of increased irradiance or decreased CO2. (ii) The amount of Rubisco in wild-type plants was reduced as the nitrogen supply during growth was reduced and this was associated with an increase in CR. This implied that there was a specific reduction in the amount of Rubisco compared with other components of the photosynthetic machinery. (iii) Plants grown with low nitrogen and which had genetically reduced levels of Rubisco had a higher chlorophyll content and a lower chlorophyll a/b ratio than wild-type plants. This indicated that the nitrogen made available by genetically reducing the amount of Rubisco had been re-allocated to other cellular components including light-harvesting and electron-transport proteins. It is argued that there is a “luxury” additional investment of nitrogen into Rubisco in tobacco plants grown in high nitrogen, and that Rubisco can also be considered a nitrogen-store, all be it one where the opportunity cost of the nitrogen storage is higher than in a non-functional storage protein (i.e. it allows for a slightly higher water-use efficiency and for photosynthesis to respond to temporarily high irradiance).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00197044
    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...