ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Publication Date: 2011-11-05
    Description: Deposition of reactive nitrogen (N) from human activities has large effects on temperate forests where low natural N availability limits productivity but is not known to affect tropical forests where natural N availability is often much greater. Leaf N and the ratio of N isotopes (delta(15)N) increased substantially in a moist forest in Panama between ~1968 and 2007, as did tree-ring delta(15)N in a dry forest in Thailand over the past century. A decade of fertilization of a nearby Panamanian forest with N caused similar increases in leaf N and delta(15)N. Therefore, our results indicate regional increases in N availability due to anthropogenic N deposition. Atmospheric nitrogen dioxide measurements and increased emissions of anthropogenic reactive N over tropical land areas suggest that these changes are widespread in tropical forests.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hietz, Peter -- Turner, Benjamin L -- Wanek, Wolfgang -- Richter, Andreas -- Nock, Charles A -- Wright, S Joseph -- New York, N.Y. -- Science. 2011 Nov 4;334(6056):664-6. doi: 10.1126/science.1211979.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institute of Botany, University of Natural Resources and Life Sciences, Gregor Mendel-Strasse 33, 1180 Vienna, Austria. peter.hietz@boku.ac.at〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22053047" target="_blank"〉PubMed〈/a〉
    Keywords: *Nitrogen Cycle ; Panama ; Plant Leaves ; Thailand ; *Trees ; *Tropical Climate
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    European journal of soil science 54 (2003), S. 0 
    ISSN: 1365-2389
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: We compared functional diversity in 6- to 150-year-old sites on two primary successional glacier forelands (Ödenwinkelkees and Rotmoosferner, Austria) and related these changes to properties of their habitat in the soil (pH, soil organic matter, mineral nitrogen, phosphorus). Comparisons were made with land undisturbed for 9500 years immediately outside the glacier foreland. The functional diversity of the soil microflora was assessed based on microbial processes (N mineralization, ammonium oxidation, arginine deaminase) as well as on the activities of soil enzymes (protease, urease, xylanase, phosphatase, arylsulphatase). On both chronosequences, functional diversity (Shannon diversity index and evenness) and enzyme activity increased up to an age of 50 years, while older soils appeared to have reached a temporary steady state. The values of microbial biomass and enzyme activity were generally smaller in the Ödenwinkel soils than in the Rotmoos sequence, indicating that primary input of carbon from plant growth was less. Functional diversity increased with increasing plant development and organic matter accumulation, explaining similarities in enzyme activity patterns in the sequences. The local climates might also have contributed to the magnitude of the changes. Our data suggest that microbial functional diversity reached stability within 50 years' succession.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Plant, cell & environment 22 (1999), S. 0 
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The foliar content of nitrogen and the relative abundances of 13C and 15N were analysed in vascular epiphytes collected from six sites along an altitudinal gradient from tropical dry forests to humid montane forests in eastern Mexico. The proportion of epiphyte species showing crassulacean acid metabolism (CAM) (atmospheric bromeliads, thick-leaved orchids, Cactaceae, and Crassulaceae) decreased with increasing elevation and precipitation from 58 to 6%. Atmospheric bromeliads, almost all of which had δ13C values indicating CAM, were more depleted in 15N (x=−10·9‰± 2·11) than the C3 bromeliads which form water-storing tanks (−6·05‰± 2·26). As there was no difference in δ15N values between C3 and CAM orchids, the difference in bromeliads was not related to photosynthetic pathways but to different nitrogen sources. While epiphytes with strong 15N depletion appear to obtain their nitrogen mainly from direct atmospheric deposition, others have access to nitrogen in intercepted water and from organic matter decomposing on branches and in their phytotelmata. Bromeliads and succulent orchids had a lower foliar nitrogen content than thin-leaved orchids, ferns and Piperaceae. Ground-rooted hemi-epiphytes exhibited the highest nitrogen contents and δ15N values.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science, Ltd
    Plant, cell & environment 25 (2002), S. 0 
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The natural 15N abundance (δ15N) of epiphytes and its N sources were studied in the canopy of a lowland rainforest in Costa Rica. Vascular and non-vascular epiphytes and canopy soils were collected from four canopy zones and analysed for N contents and δ15N signals. In addition, the N concentrations and δ15N signatures of bulk precipitation, throughfall and stemflow were measured during the wet and the dry season. The δ15N values of epiphyte leaves decreased significantly from the lower zones (means of −3·9 and −4·3‰) to the upper zones (means of −5·4 and −6·1‰) of the canopy. In contrast, δ15N signatures of canopy soils (average −0·3‰) differed little between the zones. Bulk deposition was enriched in 15N (+4·3‰) compared to all other potential N sources and was higher than throughfall and stemflow (+0·5 to −1·3‰). δ15N values of atmospheric deposition were inversely related to those of the epiphyte leaves, whereas N isotopic composition of canopy soils did not vary significantly. Consequently, it is concluded that the variations in foliar N isotope composition of epiphytes were not simply caused by utilization of isotopically different N sources, but by different 15N discrimination during N acquisition.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Plant, cell & environment 25 (2002), S. 0 
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Foliar carbon isotope discrimination (Δ) of C3 plants decreases in water-deficit situations as discrimination by the photosynthetic primary carboxylation reaction decreases. This diminished Δ in leaves under water deficit can be used as a tracer to study whole plant carbon allocation patterns. Carbon isotope composition (δ13C value) of leaf hot water extracts or leaf tissue sap represents a short-term integral of leaf carbon isotope discrimination and thus represents the δ13C value of source carbon that may be distributed within a plant in water-deficit situations. By plotting the δ13C values of source carbon against the δ13C values of sink tissues, such as roots or stems, it is possible to assess carbon allocation to and incorporation into sink organs in relation to already present biomass. This natural abundance labelling method has been tested in three independent experiments, a one-year field study with the fruit tree species Ziziphus mauritiana and peach (Prunus persica), a medium-term drought stress experiment with Ziziphus rotundifolia trees in the glasshouse, and a short-term drought stress experiment with soybean (Glycine max). The data show that the natural abundance labelling method can be applied to qualitatively assess carbon allocation in drought-stressed plants. Although it is not possible to estimate exact fluxes of assimilated carbon during water deficit the method represents an easy to use tool to study integrated plant adaptations to drought stress. In addition, it is a less laborious method that can be applied in field studies as well as in controlled experiments, with plants from any developmental stage.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 8 (1969), S. 617-617 
    ISSN: 0570-0833
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 81 (1969), S. 578-578 
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thin Layer Chromatography of Chloro-Cyclophosphazenes. II. Separation of Chloro-Cyclophosphazenes (NPCl2)n (n=3-15)Thin layer chromatography on silica gel was used for separation of higher members of homologic series of Chloro-Cyclophosphazenes. Under the indicated conditions spots of 13 substances with help of new and selective detection reagents were located. The Rf values of the substance were mathematically worked up and the probable influences that enables the separation were discussed.
    Notes: Dünnschichtchromatographie auf Silicagel wurde zur Trennung der höheren Glieder der homologen Reihe von Chloro-Cyclophosphazenen benutzt. Unter den beschriebenen Arbeitsbedingungen wurden Flecke von 13 Stoffen mit neuen empfindlichen und selektiven Nachweisverfahren ermittelt. Die Rf-Werte wurden mathematisch bearbeitet, und die wahrscheinlichen Einflusse, die die Trennung ermöglichen, wurden diskutiert.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thin Layer Chromatography of Chloro-Cyclophosphazenes I. Separation of Oligomers [MNCL2]n (n = 3 - 7)This paper presents a separation study of cyclo-chlorophosphazenes by means of thin layer chromatography on silica gel and a new sensitive method of detection of these separated substances. The chromatographic behavior of oligomers (n = 3-7) of the homologic series [NPCL2]n was experimentally studied. The Rf values of the substances were correlated with their molecular weights. As a result a Quasi-linear function was obtained for the members with n = 4-7.
    Notes: Es wurde eine Methode zur selektiven Trennung der Chlorocyclophosphazene mittels Dünnschichtchromatographie auf Silicagel und ein neues Nachweisverfahren für diesen Verbindungstyp ausgearbeitet. Experimentell wurden die Glieder der homologen Reihe [NPCL2]n bis zum Cyclo-Heptaphosphazaheptaendekaterachlorid Getrennt. Die Rf-Werte der Homologen [NPCL2]n bis [NPCL2]7 besitzen, in Abhängigkeit von der Anzahl der Phosphoratome, einen Quasi-Linearen Verlauf.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...