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
Filter
  • Life and Medical Sciences  (1)
  • Quercus robur  (1)
  • ammonia  (1)
  • 1995-1999  (3)
Collection
Publisher
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 215 (1999), S. 115-122 
    ISSN: 1573-5036
    Keywords: allocation ; beech ; cysteine ; Fagus sylvatica ; glutathione ; Laccaria laccata ; methionine ; mycorrhization ; oak ; phloem ; Quercus robur ; sulfate ; sulfur ; uptake ; xylem ; xylem loading
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Sulfur nutrition of plants is largely determined by sulfate uptake of the roots, the allocation of sulfate to the sites of sulfate reduction and assimilation, the reduction of sulfate to sulfide and its assimilation into reduced sulfur-containing amino acids and peptides, and the allocation of reduced sulfur to growing tissues that are unable to fulfill their own demand for reduced sulfur in growth and development. Association of the roots of pedunculate oak (Quercus robur L.) and beech (Fagus sylvatica L.) trees with ectomycorrhizal fungi seems to interact with these processes of sulfur nutrition in different ways, but the result of these interactions is dependent on both the plant and the fungal partners. Mycorrhizal colonisation of the roots can alter the response of sulfate uptake to sulfate availability in the soil and enhances xylem loading and, hence, xylem transport of sulfate to the leaves. As a consequence, sulfate reduction in the leaves may increase. Simultaneously, sulfate reduction in the roots seems to be stimulated by ectomycorrhizal association. Increased sulfate reduction in the leaves of mycorrhizal trees can result in enhanced phloem transport of reduced sulfur from the leaves to the roots. Different from herbaceous plants, enhanced phloem allocation of reduced sulfur does not negatively affect sulfate uptake by the roots of trees. These interactions between mycorrhizal association and the processes involved in sulfur nutrition are required to provide sufficient amounts of reduced sulfur for increased protein synthesis that is used for the enhanced growth of trees frequently observed in response to ectomycorrhizal association.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Water, air & soil pollution 116 (1999), S. 47-64 
    ISSN: 1573-2932
    Keywords: nitrate ; ammonium ; uptake ; regulation ; nitrogen oxides ; ammonia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Wet and dry deposition of atmospheric nitrogen (N) compounds into forest ecosystems and their effect on physical, chemical and microbial processes in the soil has attracted considerable attention for many years. Still the consequences of atmospheric N deposition on N metabolism of trees and its interaction with soil microbial processes has only recently been studied. Atmospheric N deposited to the leaves is thought to enter the general N metabolism of the leaves, but the processes involved, the interaction with different metabolic pathways, and the connection between injury by atmospheric N and its metabolic conversion are largely unknown. Laboratory and field experiments have shown that N of atmospheric NO2 and NH3, deposited to the leaves of trees, is subject to long-distance transport in the phloem to the roots. This allocation can result in considerable decline of N uptake by the roots. Apparently, the flux of N from the soil into the roots can be down-regulated to an extent that equals N influx into the leaves. This down-regulation is not mediated by generally enhanced amino-N contents, but by elevated levels of particular amino acids. Field experiments confirm these results from laboratory studies: Nitrate (NO3) uptake by the roots of trees at a field sites exposed to high loads of atmospheric N is negligible, provided concentrations of Gln in the roots are high. At the ecosystem level, consequences of reduced N uptake by the roots of trees exposed to high loads of atmospheric N are (1) an increased availability of N for soil microbial processes, (2) enhanced emission of gaseous N-oxides from the soil, and (3) elevated leaching of NO3 into the ground water. How recent forest management practices aimed at transforming uniform monocultures to more structured species-rich forests will interact with these processes remains to be seen. Possible implications of these forest management practices on N metabolism in trees and N conversion in the soil are discussed particularly in relation to atmospheric N deposition.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Biologie in unserer Zeit 26 (1996), S. 272-281 
    ISSN: 0045-205X
    Keywords: Life and Medical Sciences
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Im Gegensatz zu anderen landwirtschaftlichen Nutzungsformen ist der Reisanbau durch einen hohen Anteil von zeitweise oder permanent gefluteten Feldern gekennzeichnet. Bei anhaltender Flutung wird die Sauerstoffzufuhr in den Boden unterbunden und durch den anaeroben Abbau organischen Materials das Treibhausgas Methan gebildet. Ein Teil des im Boden entstehenden Methans wird in Form von Gasblasen, durch Diffusion üer die Wasseroberfläche oder nach Transport durch die Reispflanze in die Atmosphäre Reispflanze in die Atmosphäre abgegeben. Insbesondere der Transport durch die Reispflanze führt zu einer massiven Emission von Methan in die Atmosphäre, so daß der Reisanbau heute als eine der wichtigsten Quellen dieses atmosphärischen Spurengases angesehen wird. Die Freisetzung von Methan aus Reisfeldern in die Atmosphäre wird durch ein komplexes Zusammenwirken natürlicher und anthropogener Faktoren bestimmt. Hierzu zählen Zeitpunkt, Umfang und Art der Düngung, Zeitpunkt und Dauer von Drainagen, morphologisch-anatomische Eigenschaften der Reispflanzen usw. Die Kenntnis dieser Faktoren bietet vielfältige Ansatzpunkte, um die Methanemission aus dem Reisanbau zu reduzieren und damit den atmosphärischen Methanhaushalt mittelfristig zu stabilisieren.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...