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  • 1
    Language: English
    In: Plant and Soil, 2016, Vol.409(1), pp.143-157
    Description: Aims The role of different soil types for beech productivity and drought sensitivity is unknown. The aim of this experimental study was to compare mycorrhizal diversity between acid sandy and calcareous soils and to investigate how this diversity affects tree performance, nitrogen uptake and use efficiency (NUE). Methods Beech trees were germinated and grown in five different soil types (pH 3.8 to 6.7). One-and-a-half-year-old plants were exposed for 6 weeks to sufficient or low soil humidity. Tree biomass, root tip mycorrhizal colonization and community structure, root tip mortality, leaf area, photosynthesis, nitrogen concentrations, NUE and short-term .sup.15N uptake from glutamine were determined. Results Soil type did not affect photosynthesis or biomass formation, with one exception in calcareous soil, where root mortality was higher than in the other soil types. Beech in acid soils showed lower mycorrhizal colonization, higher nitrogen tissue concentrations, and lower NUE than those in calcareous soils. Drought had no effect on nitrogen concentrations or NUE but caused reductions in mycorrhizal colonization. Mycorrhizal species richness correlated with nitrogen uptake and NUE. Nitrogen uptake was more sensitive to drought in calcareous soils than in acid soils. Conclusions Beech may be more drought-susceptible on calcareous sites because of stronger decrease of organic nitrogen uptake than on acid soils.
    Keywords: Ectomycorrhizal fungi ; Organic nitrogen ; Glutamine uptake ; Drought ; N concentration ; Beech ; Fagus sylvatica ; Calcareous soil ; Acid soil
    ISSN: 0032-079X
    E-ISSN: 1573-5036
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  • 2
    Language: English
    In: Applied and Environmental Microbiology, Sept 1, 2015, Vol.81(17), pp.5957-5967
    Description: Study is conducted to test the hypothesis that ectomycorrhizal communities and the free-living rhizosphere microbes from beech trees from sites with two distinct climatic conditions shows differences in N acquisition. To test these hypotheses, young trees from dryer conditions and also from cooler, moist climate conditions are transplanted and it concluded that the ectomycorrhizal community influences N transfer to its host and fungal community from dry condition are efficient in N acquisition.
    Keywords: Mycorrhizae – Research ; Mycorrhizae – Physiological Aspects ; Beeches – Research ; Beeches – Physiological Aspects
    ISSN: 0099-2240
    Source: Cengage Learning, Inc.
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  • 3
    Language: English
    In: Applied and environmental microbiology, 01 September 2015, Vol.81(17), pp.5957-67
    Description: Beech (Fagus sylvatica), a dominant forest species in Central Europe, competes for nitrogen with soil microbes and suffers from N limitation under dry conditions. We hypothesized that ectomycorrhizal communities and the free-living rhizosphere microbes from beech trees from sites with two contrasting climatic conditions exhibit differences in N acquisition that contribute to differences in host N uptake and are related to differences in host belowground carbon allocation. To test these hypotheses, young trees from the natural regeneration of two genetically similar populations, one from dryer conditions (located in an area with a southwest exposure [SW trees]) and the other from a cooler, moist climate (located in an area with a northeast exposure [NE trees]), were transplanted into a homogeneous substrate in the same environment and labeled with (13)CO2 and (15)NH4 (+). Free-living rhizosphere microbes were characterized by marker genes for the N cycle, but no differences between the rhizospheres of SW or NE trees were found. Lower (15)N enrichment was found in the ectomycorrhizal communities of the NE tree communities than the SW tree communities, whereas no significant differences in (15)N enrichment were observed for nonmycorrhizal root tips of SW and NE trees. Neither the ectomycorrhizal communities nor the nonmycorrhizal root tips originating from NE and SW trees showed differences in (13)C signatures. Because the level of (15)N accumulation in fine roots and the amount transferred to leaves were lower in NE trees than SW trees, our data support the suggestion that the ectomycorrhizal community influences N transfer to its host and demonstrate that the fungal community from the dry condition was more efficient in N acquisition when environmental constraints were relieved. These findings highlight the importance of adapted ectomycorrhizal communities for forest nutrition in a changing climate.
    Keywords: Fagus -- Microbiology ; Fungi -- Metabolism ; Mycorrhizae -- Metabolism ; Nitrogen -- Metabolism
    ISSN: 00992240
    E-ISSN: 1098-5336
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  • 4
    In: Plant, Cell & Environment, December 2016, Vol.39(12), pp.2691-2700
    Description: Here, we characterized nitrogen (N) uptake of beech () and their associated ectomycorrhizal (EM) communities from NH and NO. We hypothesized that a proportional fraction of ectomycorrhizal N uptake is transferred to the host, thereby resulting in the same uptake patterns of plants and their associated mycorrhizal communities. N uptake was studied under various field conditions after short‐term and long‐term exposure to a pulse of equimolar NH and NO concentrations, where one compound was replaced by N. In native EM assemblages, long‐term and short‐term N uptake from NH was higher than that from NO, regardless of season, water availability and site exposure, whereas in beech long‐term N uptake from NO was higher than that from NH. The transfer rates from the EM to beech were lower for N from NH than from NO. N content in EM was correlated with N uptake of the host for NH, but not for NO‐derived N. These findings suggest stronger control of the EM assemblage on N provision to the host from NH than from NO. Different host and EM accumulation patterns for inorganic N will result in complementary resource use, which might be advantageous in forest ecosystems with limited N availability. Ammonium (NH) and nitrate (NO) uptake of beech () and their associated ectomycorrhizal (EM) assemblages were studied by N labelling under field conditions. In native EM assemblages, long‐term and short‐term N uptake from NH was higher than that from NO, regardless of season, water availability and site exposure, whereas in beech long‐term N uptake from NO was higher than that from NH. The transfer rates from the EM to beech were lower for N from NH than that from NO. N content in EM was correlated with NH, but not with NO‐derived N uptake of the plant, suggesting a stronger control of the EM assemblage on N provision to the host from NH than that from NO.
    Keywords: Drought ; Ectomycorrhiza ; Temperate Forest
    ISSN: 0140-7791
    E-ISSN: 1365-3040
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  • 5
    Language: English
    In: PLoS ONE, 01 January 2016, Vol.11(7), p.e0158823
    Description: European beech forests growing on marginal calcareous soils have been proposed to be vulnerable to decreased soil water availability. This could result in a large-scale loss of ecological services and economical value in a changing climate. In order to evaluate the potential consequences of this drought-sensitivity, we investigated potential species range shifts for European beech forests on calcareous soil in the 21st century by statistical species range distribution modelling for present day and projected future climate conditions. We found a dramatic decline by 78% until 2080. Still the physiological or biogeochemical mechanisms underlying the drought sensitivity of European beech are largely unknown. Drought sensitivity of beech is commonly attributed to plant physiological constraints. Furthermore, it has also been proposed that reduced soil water availability could promote nitrogen (N) limitation of European beech due to impaired microbial N cycling in soil, but this hypothesis has not yet been tested. Hence we investigated the influence of simulated climate change (increased temperatures, reduced soil water availability) on soil gross microbial N turnover and plant N uptake in the beech-soil interface of a typical mountainous beech forest stocking on calcareous soil in SW Germany. For this purpose, triple 15N isotope labelling of intact beech seedling-soil-microbe systems was combined with a space-for-time climate change experiment. We found that nitrate was the dominant N source for beech natural regeneration. Reduced soil water content caused a persistent decline of ammonia oxidizing bacteria and therefore, a massive attenuation of gross nitrification rates and nitrate availability in the soil. Consequently, nitrate and total N uptake of beech seedlings were strongly reduced so that impaired growth of beech seedlings was observed already after one year of exposure to simulated climatic change. We conclude that the N cycle in this ecosystem and here specifically nitrification is vulnerable to reduced water availability, which can directly lead to nutritional limitations of beech seedlings. This tight link between reduced water availability, drought stress for nitrifiers, decreased gross nitrification rates and nitrate availability and finally nitrate uptake by beech seedlings could represent the Achilles' heel for beech under climate change stresses.
    Keywords: Sciences (General)
    E-ISSN: 1932-6203
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  • 6
    Language: English
    In: Microbial Ecology, 2015, Vol.69(4), pp.867-878
    Description: Soil microbial community responses to elevated atmospheric CO 2 concentrations (eCO 2 ) occur mainly indirectly via CO 2 -induced plant growth stimulation leading to quantitative as well as qualitative changes in rhizodeposition and plant litter. In order to gain insight into short-term, site-specific effects of eCO 2 on the microbial community structure at the plant-soil interface, young beech trees ( Fagus sylvatica L.) from two opposing mountainous slopes with contrasting climatic conditions were incubated under ambient (360 ppm) CO 2 concentrations in a greenhouse. One week before harvest, half of the trees were incubated for 2 days under eCO 2 (1,100 ppm) conditions. Shifts in the microbial community structure in the adhering soil as well as in the root rhizosphere complex (RRC) were investigated via TRFLP and 454 pyrosequencing based on 16S ribosomal RNA (rRNA) genes. Multivariate analysis of the community profiles showed clear changes of microbial community structure between plants grown under ambient and elevated CO 2 mainly in RRC. Both TRFLP and 454 pyrosequencing showed a significant decrease in the microbial diversity and evenness as a response of CO 2 enrichment. While Alphaproteobacteria dominated by Rhizobiales decreased at eCO 2 , Betaproteobacteria , mainly Burkholderiales , remained unaffected. In contrast, Gammaproteobacteria and Deltaproteobacteria, predominated by Pseudomonadales and Myxococcales , respectively, increased at eCO 2 . Members of the order Actinomycetales increased, whereas within the phylum Acidobacteria subgroup Gp1 decreased, and the subgroups Gp4 and Gp6 increased under atmospheric CO 2 enrichment. Moreover, Planctomycetes and Firmicutes , mainly members of Bacilli , increased under eCO 2 . Overall, the effect intensity of eCO 2 on soil microbial communities was dependent on the distance to the roots. This effect was consistent for all trees under investigation; a site-specific effect of eCO 2 in response to the origin of the trees was not observed.
    Keywords: Rhizosphere ; Beech ; Bacterial communities ; CO
    ISSN: 0095-3628
    E-ISSN: 1432-184X
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  • 7
    Language: German
    Description: Die Buche (Fagus sylvatica L.) ist sowohl in ökonomischer als auch in ökologischer Hinsicht in Mitteleuropa eine sehr wichtige Baumart. Häufig sind Buchenwälder auf Böden anzutreffen, auf denen Stickstoff das limitierende Nährelement ist. Auf solchen Böden konkurrieren deshalb Buchen, Ektomykorrhizapilze und Bodenbakterien um den verfügbaren Stickstoff. Der prognostizierte Klimawandel mit steigenden Temperaturen, Trockenperioden und Starkregenereignissen wird den Stickstoffkreislauf und die Konkurrenzverhältnisse beeinflussen, da sich zwei der wichtigsten Bodenparameter, Bodenfeuchte und Bodentemperatur, verändern werden. In diesen Parameter unterscheiden sich auch die beiden Versuchsflächen in Baden-Württemberg in der Nähe von Tuttlingen, die für die Versuche dieser Arbeit ausgewählt wurden. Die Flächen befinden sich gegenüberliegend in einem Tal und sind auf der einen Seite NO bez. NW exponiert und auf der anderen Seite SW exponiert. Der SW-Hang weist im Vergleich zu den nördlich exponierten Hängen eine erhöhte Bodentemperatur und eine verminderte Bodenfeuchte auf und kann damit als Modellstandort für das prognostizierte zukünftige Klima gelten. Wie die Buche mit den erwarteten klimatischen Änderungen umgehen wird, wird unter anderem auch von der Reaktion der Ektomykorrhizapilze abhängen. Diese spielen bei der Stickstoffaufnahme der Buchen eine entscheidende Rolle, da die Wurzelspitzen der Buche in natürlichen Ökosystemen praktisch vollständig mit Ektomykorrhizapilzen kolonisiert sind. Um die komplex zusammengesetzten Mykorrhizagesellschaften an Buchen charakterisieren und in Bezug auf ihre Funktion analysieren zu können, sind Informationen über die Morphologie und Anatomie der einzelnen Pilzarten notwendig. Selbst in Mitteleuropa fehlen aber für einen Großteil der Ektomykorrhizen exakte wissenschaftliche Beschreibungen. Daher wurde exemplarisch ein mykorrhizaler Morphotyp, der auf den Tuttlinger Versuchsflächen häufig vorkommt, morphologisch und anatomisch beschrieben und gezeichnet. Wegen seiner dicht mit langen Cystiden besetzten Manteloberfläche wird er dem „Short distance“-Explorationstyp zugeordnet. Besonders auffällig sind die drei bis sechsfachen Verzweigungspunkten der Cystiden, die charakteristisch verdickt sind und denen die Mykorrhiza ihren provisorischen Namen „Fagirhiza inflata“ verdankt. Die aufgrund der anatomischen Merkmale und der dextrinoiden Reaktion von Mantel und Cystiden mit Melzers Reagenz angenommene Zugehörigkeit zur Gattung Sebacina wurde durch die ITS-Sequenzierung bestätigt. Bisher war unklar, ob die Stickstoffversorgung von Buchen unter gegebenen Bedingungen von den Bodenmikroben, den Mykorrhizapilzen oder der Herkunft der Bäume abhängt. In einem Experiment sollte untersucht werden, ob und wie sich die unterschiedliche Artenzusammensetzung von Mykorrhizagesellschaften auf die Stickstoffakkumulation in den mykorrhizierten Wurzelspitzen und den Stickstofftransfer zu den Pflanzen auswirkt. Es wurden junge, genetisch ähnliche Buchen mit ihren assoziierten Mykorrhiza¬gesellschaften aus Tuttlingen von einem NO-Hang und einem SW-Hang in einen homogenen Boden transferiert und unter gleichen klimatischen Bedingungen mit 13C und 15N markiert. Die geringe mikrobielle Biomasse im Substrat führte dazu, dass die Konkurrenz um den Stickstoff mit Bakterien stark vermindert wurde. Die nicht mykorrhizierten Wurzelspitzen der NO- und SW-Buchen akkumulierten unter diesen Bedingungen das 15N gleich stark. Im Gegenteil dazu akkumulierten die mykorrhizierten Wurzelspitzen der NW-Buchen das 15N stark verzögert im Vergleich zu den mykorrhizierten Wurzelspitzen der SW-Buchen. Korrespondierend dazu dauerte bei den NO-Buchen der Transfer des 15N zu den Feinwurzeln und Blättern länger und erfolgte in niedrigeren Raten als bei den SW-Buchen. Daraus folgt, dass die Mykorrhizagesellschaften den N-Transport zur Pflanze kontrollierten. Außerdem zeigen diese Ergebnisse, dass die Mykorrhizapilze, die sich an trockene und warme Bedingungen angepasst haben, die Leistungsfähigkeit von den an moderate Bedingungen angepassten Mykorrhizapilzen in Bezug auf die Akkumulation von Stickstoff sogar übertreffen, wenn die umweltbedingten Einschränkungen wegfallen. Die Ergebnisse legen nahe, dass die Zusammensetzung der Mykorrhizagesellschaften entscheidend für die Zukunftsfähigkeit der Buchenwälder ist. Um die Auswirkungen des prognostizierten Klimawandels (erhöhte Temperatur und niedrigere Bodenfeuchte) auf die Stickstoffversorgung von Buchen abschätzen zu können, wurde Buchennaturverjüngung mit umgebendem Boden (Mesokosmen) in Tuttlingen von dem NW-Hang auf den gegenüberliegenden SW-Hang ("Klimawandel" Behandlung) oder von dem NW auf den NW Hang (Kontrolle) transferiert. Die Buchen wurden für ein Jahr unter diesen Bedingungen kultiviert. In der nachfolgenden Vegetationsperiode wurde nach Injizieren von 15N markierten Stickstoffformen (Glutamin, Ammonium, Nitrat) in den Boden an mehreren Zeitpunkten geerntet. Anhand der 15N-Aufnahmeraten stellte sich Nitrat als die dominierende Stickstoffquelle für die Buchen heraus. Die klimatischen Bedingungen auf der SW-Seite führten zu einem Einbruch bei der Nitratbereitstellung durch die Bodenbakterien und damit zu Nitratmangel und nachfolgend zu einer Reduktion der Biomasse der Buchennaturverjüngung. In den mykorrhizierten Wurzelspitzen hingegen zeigte sich durchgängig, dass 15N aus Ammonium am stärksten akkumuliert wurde, gefolgt von Nitrat und Glutamin. In den meisten Fällen wurde auf der SW-Seite signifikant oder tendenziell weniger 15N akkumuliert als auf der NW-Seite. Intaktes Glutamin wurde weder in den mykorrhizierten Wurzelspitzen noch in den Buchen festgestellt, was auf eine sehr geringe Bedeutung von organischen Stickstoffformen für die Stickstoffversorgung der Buchen schließen lässt. Die Ergebnisse lassen befürchten, dass es in Zukunft große Probleme bei der Stickstoffversorgung der Buche geben wird. Vermutlich sind diese Restriktionen in der Stickstoffversorgung eine der Ursache für die prognostizierte erhebliche Reduktion der Kalkbuchenwälder bis zum Ende des 21. Jahrhunderts.
    Keywords: 570 ; Ektomykorrhiza ; Stickstoff ; Buche ; Ectomycorrhiza ; Nitrogen ; Beech ; Forstwirtschaft (Ppn621305413)
    Source: Networked Digital Library of Theses and Dissertations
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  • 8
    Language: German
    Keywords: Religion ; Religion & Beliefs ; Theology
    ISBN: 9783111244600
    Source: VLeBooks
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  • 9
    Book
    Book
    Berlin, Boston: De Gruyter
    Language: English
    Description: Intro -- Vorwort -- Inhalt -- Erste Vorlesung. Einleitung in die Sittenlehre -- Zweyte Vorlesung. Fortsetzung der Einleitung -- Dritte Vorlesung. Beschluß der Einleitung -- Vierte Vorlesung. Sittliche Natur des Menschen -- Fünfte Vorlesung. Die geistigen Triebe -- Sechste Vorlesung. Der sittliche oder...
    Keywords: Ethics;
    ISBN: 9783111102023
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  • 10
    Language: German
    Keywords: Economics ; Economics ; Political Economy ; Business & Management
    ISBN: 9783111102016
    Source: VLeBooks
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