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Berlin Brandenburg

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  • Springer (CrossRef)  (45)
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  • 1
    Language: English
    In: Plant and Soil, 2013, Vol.364(1), pp.287-301
    Description: Background and aims: Nitrous oxide (N sub(2)O) and methane (CH sub(4)) can be emitted from surfaces of riparian plants. Data on the emission of these greenhouse gases by upland trees are scarce. We quantified CH sub(4) and N sub(2)O emissions from stems of Fagus sylvatica, an upland tree, and Alnus glutinosa, a riparian tree. Methods: The gas fluxes were investigated in mesocosms under non-flooded control conditions and during a flooding period using static chamber systems and gas chromatographic analyses. Results: Despite differences in the presence of an aerenchyma system, both tree species emitted N sub(2)O and CH sub(4) from the stems. Flooding caused a dramatic transient increase of N sub(2)O stem emissions by factors of 740 (A. glutinosa) and even 14,230 (F. sylvatica). Stem emissions of CH sub(4) were low and even deposition was determined (F. sylvatica controls). The results suggest that CH sub(4) was transported mainly through the aerenchyma, whereas N sub(2)O transport occurred in the xylem sap. Conclusions: For the first time it has been demonstrated that upland trees such as F. sylvatica clearly significantly emit N sub(2)O from their stems despite lacking an aerenchyma. If this result is confirmed in adult trees, upland forests may constitute a new and significant source of atmospheric N sub(2)O.
    Keywords: Methane ; Nitrous oxide ; Soil and stem emission ; Alnus glutinosa ; Fagus sylvatica ; Flooding
    ISSN: 0032-079X
    E-ISSN: 1573-5036
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  • 2
    Language: English
    In: Plant and Soil, 2013, Vol.368(1), pp.519-534
    Description: Background and aims: Litter decomposition is regulated by e.g. substrate quality and environmental factors, particularly water availability. The partitioning of nutrients released from litter between vegetation and soil microorganisms may, therefore, be affected by changing climate. This study aimed to elucidate the impact of litter type and drought on the fate of litter-derived N in beech seedlings and soil microbes. Methods: We quantified super(15)N recovery rates in plant and soil N pools by adding super(15)N-labelled leaf and/or root litter under controlled conditions. Results: Root litter was favoured over leaf litter for N acquisition by beech seedlings and soil microorganisms. Drought reduced super(15)N recovery from litter in seedlings thereby affecting root N nutrition. super(15)N accumulated in seedlings in different sinks depending on litter type. Conclusions: Root turnover appears to influence (a) N availability in the soil for plants and soil microbes and (b) N acquisition and retention despite a presumably extremely dynamic turnover of microbial biomass. Compared to soil microorganisms, beech seedlings represent a very minor short-term N sink, despite a potentially high N residence time. Furthermore, soil microbes constitute a significant N pool that can be released in the long term and, thus, may become available for N nutrition of plants.
    Keywords: Litter types ; Root litter ; Leaf litter ; Decomposition ; Microbial biomass ; Plant N metabolism ; Soil N pools ; N recovery
    ISSN: 0032-079X
    E-ISSN: 1573-5036
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  • 3
    Language: English
    In: Plant and Soil, 2010, Vol.332(1), pp.387-403
    Description: The root/shoot-ratio is a simple parameter to describe the systemic response of plants to alterations of their nutritional status, as indicated by the C/N-balance of leaves. The ‘functional equilibrium hypothesis’ holds that leaf growth is limited by the supply of nitrogen from the roots, whereas root growth depends on the carbon supply from leaves. The nature of the systemic control that balances root and shoot growth is not fully understood. Previous experiments have shown that root growth of transformed tobacco plants, which lack functional root nitrate reductase, was severely impeded, when plants were grown on NO 3 − as the sole N-source. In these experiments, the root/shoot-ratio was correlated with the Glutamate/Glutamine-ratio of roots. In the present study we tested the hypothesis that high internal Glu contents (in relation to Gln) inhibit root growth. Wild type and transformed tobacco plants were given access to both NH 4 and NO 3 , and were cultivated at ambient and elevated p CO 2 in order to vary carbon availability. The uptake and assimilation of NH 4 + by the root was significantly higher in transformed than in wild type tobacco, in particular at elevated p CO 2 . Consequently, the Glu/Gln-ratio in the root of transformants was significantly lower than in NO 3 − -grown plants, and was, in the present study, not different from the wild type. However, we failed to observe a correlation between plant architecture and the Glu/Gln-ratio of roots, suggesting that signals arising from the immediate products of nitrate reduction (nitrite) are involved in the systemic control of root growth. Furthermore the synthesis of root-derived signals, which affect N-turnover, starch re-mobilization and the growth of leaves, appears to be associated with root nitrate reduction. This enzymatic step seems to be indispensable for the systemic control of biomass partitioning, and plays a crucial role for the integration of carbon and nitrogen metabolism at the whole plant level.
    Keywords: Systemic control ; C/N-balance ; Root: shoot ratio ; Nitrate reduction ; Ammonium assimilation ; Glutamate signalling
    ISSN: 0032-079X
    E-ISSN: 1573-5036
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  • 4
    Language: English
    In: Plant and Soil, 2013, Vol.369(1), pp.657-668
    Description: Aims: Our aims were to characterize the fate of leaf-litter-derived nitrogen in the plant-soil-microbe system of a temperate beech forest of Southern Germany and to identify its importance for N nutrition of beech seedlings. Methods: super(15)N-labelled leaf litter was traced in situ into abiotic and biotic N pools in mineral soil as well as into beech seedlings and mycorrhizal root tips over three growing seasons. Results: There was a rapid transfer of super(15)N into the mineral soil already 21 days after tracer application with soil microbial biomass initially representing the dominant litter-N sink. However, super(15)N recovery in non-extractable soil N pools strongly increased over time and subsequently became the dominant super(15)N sink. Recovery in plant biomass accounted for only 0.025 % of super(15)N excess after 876 days. After three growing seasons, super(15)N excess recovery was characterized by the following sequence: non-extractable soil N〉〉extractable soil N including microbial biomass〉〉plant biomass〉ectomycorrhizal root tips. Conclusions: After quick vertical dislocation and cycling through microbial N pools, there was a rapid stabilization of leaf-litter-derived N in non-extractable N pools of the mineral soil. Very low super(15)N recovery in beech seedlings suggests a high importance of other N sources such as root litter for N nutrition of beech understorey.
    Keywords: Nitrogen cycling ; Beech ; 15N-labelled leaf litter ; 15N tracing ; Microbial biomass ; Ectomycorrhiza
    ISSN: 0032-079X
    E-ISSN: 1573-5036
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  • 5
    Language: English
    In: Oecologia, 2014, Vol.174(3), pp.839-851
    Description: Plant carnivory represents an exceptional means to acquire N. Snap traps of Dionaea muscipula serve two functions, and provide both N and photosynthate. Using 13 C/ 15 N-labelled insect powder, we performed feeding experiments with Dionaea plants that differed in physiological state and N status (spring vs. autumn plants). We measured the effects of 15 N uptake on light-saturated photosynthesis ( A max ), dark respiration ( R D ) and growth. Depending on N status, insect capture briefly altered the dynamics of R D / A max , reflecting high energy demand during insect digestion and nutrient uptake, followed by enhanced photosynthesis and growth. Organic N acquired from insect prey was immediately redistributed, in order to support swift renewal of traps and thereby enhance probability of prey capture. Respiratory costs associated with permanent maintenance of the photosynthetic machinery were thereby minimized. Dionaea’s strategy of N utilization is commensurate with the random capture of large prey, occasionally transferring a high load of organic nutrients to the plant. Our results suggest that physiological adaptations to unpredictable resource availability are essential for Dionaea’s success with regards to a carnivorous life style.
    Keywords: Plant carnivory ; Cost/benefit ; Photosynthetic efficiency ; Respiration ; Nitrogen uptake
    ISSN: 0029-8549
    E-ISSN: 1432-1939
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  • 6
    Language: English
    In: Planta, 2015, Vol.241(3), pp.579-589
    Description: Byline: Bin Liu (1), Heinz Rennenberg (1,2), Jurgen Kreuzwieser (1) Keywords: Nitrate; Nitrate reductase; Nitric oxide emission; Oxygen deficiency; Root-to-shoot transport Abstract: Main conclusion Hypoxia leads to NO formation in poplar roots. Additionally, either NO or a NO derivative is transported from the roots to the shoot causing NO emission from aboveground plant organs. Nitric oxide (NO) is involved in the response of plants to various forms of stress including hypoxia. It also seems to play an important role in stomatal closure during stress exposure. In this study, we investigated the formation of NO in roots of intact poplar (Populus x canescens) plants in response to hypoxia, as well as its dependence on nitrate availability. We further addressed the question if root hypoxia triggers NO emission from aboveground plant parts, i.e., stems and leaves of young poplar trees. Our results indicate that NO is formed in poplar roots in response to hypoxia and that this production depends on the availability of nitrate and its conversion product nitrite. As long as nitrate was available in the nutrient solution, NO emission of roots occurred in the range of the nitrate concentrations (10--100 A[micro]M) tested, NO emission was widely independent on nitrate concentration. However, the time period in which NO was emitted and the total amount of NO emitted strongly depended on the nitrate concentration of the solution. Hypoxia also led to increased NO emissions from the leaves and stems of the trees. There was a tight correlation between leaf and stem NO emission of hypoxia-treated plants. We propose that NO is produced by nitrate reductase in the roots and either NO itself, a metabolic NO precursor, or a NO derivative is transported in the xylem sap of the trees from the roots to the shoot thereby mediating NO emission from aboveground parts of the plant. Author Affiliation: (1) Institut fur Forstwissenschaften, Albert-Ludwigs-Universitat Freiburg, Georges-Kohler-Allee Geb. 053/054, 79110, Freiburg, Germany (2) King Saud University, Riyadh, Saudi Arabia Article History: Registration Date: 31/10/2014 Received Date: 23/07/2014 Accepted Date: 28/10/2014 Online Date: 15/11/2014
    Keywords: Nitrate ; Nitrate reductase ; Nitric oxide emission ; Oxygen deficiency ; Root-to-shoot transport
    ISSN: 0032-0935
    E-ISSN: 1432-2048
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  • 7
    Language: English
    In: Photosynthesis Research, 2016, Vol.129(1), pp.43-58
    Description: Steady-state rates of leaf CO 2 assimilation ( A ) in response to incubation temperature ( T ) are often symmetrical around an optimum temperature. A / T curves of C 3 plants can thus be fitted to a modified Arrhenius equation, where the activation energy of A close to a low reference temperature is strongly correlated with the dynamic change of activation energy to increasing incubation temperature. We tested how [CO 2 ] 〈 current atmospheric levels and saturating light, or [CO 2 ] at 800 µmol mol −1 and variable light affect parameters that describe A / T curves, and how these parameters are related to known properties of temperature-dependent thylakoid electron transport. Variation of light intensity and substomatal [CO 2 ] had no influence on the symmetry of A / T curves, but significantly affected their breadth. Thermodynamic and kinetic (physiological) factors responsible for (i) the curvature in Arrhenius plots and (ii) the correlation between parameters of a modified Arrhenius equation are discussed. We argue that the shape of A / T curves cannot satisfactorily be explained via classical concepts assuming temperature-dependent shifts between rate-limiting processes. Instead the present results indicate that any given A / T curve appears to reflect a distinct flux mode, set by the balance between linear and cyclic electron transport, and emerging from the anabolic demand for ATP relative to that for NADPH.
    Keywords: Temperature response ; Non-linear Arrhenius plot ; Cyclic electron flow ; Photorespiration
    ISSN: 0166-8595
    E-ISSN: 1573-5079
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  • 8
    Language: English
    In: Trees, 2014, Vol.28(2), pp.399-411
    Description: Byline: Dorte Randewig (1), Domenica Hamisch (2), Monika Eiblmeier (1), Christian Boedecker (2), Jurgen Kreuzwieser (1), Ralf R. Mendel (2), Robert Hansch (2), Cornelia Herschbach (1), Heinz Rennenberg (1,3) Keywords: APR, Adenosine 5 -phosphosulfate reductase; Gas exchange; GSH, Glutathione; Sulfate; SO, Sulfite oxidase; Sulfur dioxide Abstract: Key Message The critical level for SO .sub.2 susceptibility of Populus x canescens is approximately 1.2 uL L .sup.-1 SO .sub.2 . Both sulfite oxidation and sulfite reduction and assimilation contribute to SO .sub.2 detoxification. Abstract In the present study, uptake, susceptibility and metabolism of SO.sub.2 were analyzed in the deciduous tree species poplar (Populus x canescens). A particular focus was on the significance of sulfite oxidase (SO) for sulfite detoxification, as SO has been characterized as a safety valve for SO.sub.2 detoxification in herbaceous plants. For this purpose, poplar plants were exposed to different levels of SO.sub.2 (0.65, 0.8, 1.0, 1.2 uL L.sup.-1) and were characterized by visible injuries and at the physiological level. Gas exchange parameters (stomatal conductance for water vapor, CO.sub.2 assimilation, SO.sub.2 uptake) of the shoots were compared with metabolite levels (sulfate, thiols) and enzyme activities [SO, adenosine 5 -phosphosulfate reductase (APR)] in expanding leaves (80--90 % expanded). The critical dosage of SO.sub.2 that confers injury to the leaves was 1.2 uL L.sup.-1 SO.sub.2. The observed increase in sulfur containing compounds (sulfate and thiols) in the expanding leaves strongly correlated with total SO.sub.2 uptake of the plant shoot, whereas SO.sub.2 uptake rate was strongly correlated with stomatal conductance for water vapor. Furthermore, exposure to high concentration of SO.sub.2 revealed channeling of sulfite through assimilatory sulfate reduction that contributes in addition to SO-mediated sulfite oxidation to sulfite detoxification in expanding leaves of this woody plant species. Author Affiliation: (1) Fakultat fur Umwelt und Naturliche Ressourcen (UNR), Institut fur Forstwissenschaften, Professur fur Baumphysiologie, Albert-Ludwigs-Universitat Freiburg, Georges-Kohler Allee 53/54, 79085, Freiburg, Germany (2) Institut fur Pflanzenbiologie, Technische Universitat Braunschweig, Humboldtstrasse 1, 38106, Braunschweig, Germany (3) King Saud University, PO Box 2454, Riyadh, 11451, Saudi Arabia Article History: Registration Date: 08/11/2013 Received Date: 23/10/2013 Accepted Date: 08/11/2013 Online Date: 27/12/2013 Article note: Communicated by W. Bilger. Electronic supplementary material The online version of this article (doi: 10.1007/s00468-013-0958-x) contains supplementary material, which is available to authorized users.
    Keywords: APR, Adenosine 5′-phosphosulfate reductase ; Gas exchange ; GSH, Glutathione ; Sulfate ; SO, Sulfite oxidase ; Sulfur dioxide
    ISSN: 0931-1890
    E-ISSN: 1432-2285
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  • 9
    Language: English
    In: Plant and Soil, 2017, Vol.418(1), pp.89-114
    Description: Background For 15+ years, a beech (Fagus sylvatica L.) dominated forest on calcareous soil was studied on two opposing slopes with contrasting microclimate in Tuttlingen, Swabian Alb, Germany. The cool-humid NE aspect of these slopes represents the majority of beech forests under current climate, the warmer and drier SW aspect represents beech forests under future climate conditions. The field studies were supplemented by investigations under controlled conditions. Scope The research program aimed to provide a comprehensive understanding of plant-soil-microbe water, carbon and nitrogen feedbacks in a changing climate and a holistic view of the sensitivity of beech to climate change. Conclusions The results of comparative and experimental studies underpin the high vulnerability of adult beech and its natural regeneration on calcareous soil to both direct climate change effects on plant physiology and indirect effects mediated by soil biogeochemical cycles. Mechanisms contributing to this vulnerability at the ecosystem and organismic level indicate a high significance of competitive interactions of beech with other vegetation components and soil microbial communities. Obvious forest management practices such as selective felling did not necessarily counteract negative effects of climate change.
    Keywords: Climate extremes ; Competition ; Forest management strategies ; Girdling ; Rhizodeposition and mycorrhiza ; Thinning
    ISSN: 0032-079X
    E-ISSN: 1573-5036
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  • 10
    Language: English
    In: Plant and Soil, 1996, Vol.180(2), pp.197-208
    Description: The fluxes of NO and NO 2 between wheat canopy monoliths and the atmosphere were investigated with the dynamic chamber technique. For this purpose monoliths were dug out at different plant growth stages from a field site, transported to the institute, and placed in an environmental growth chamber. The wheat canopy monoliths were exposed over a period of four days to the average ratios of atmospheric NO 2 and NO measured at the field site, i.e. NO 2 concentration of about 18 mL L -1 plus NO concentration lower than 0.5 nL L -1 . Under these conditions NO emission into the atmosphere and NO 2 deposition into canopy monoliths was observed. Both fluxes showed diurnal variation with maximum rates during the light and minimum rates during darkness. NO 2 fluxes correlated with soil temperature as well as with light intensity. NO fluxes correlated with soil temperature but not with light intensity. From the investigation performed the diurnal variation of the NO and NO 2 compensation points, the maximum rates of NO and NO 2 emission, and the total resistances of NO and NO 2 fluxes were calculated. Under the assumption that the measured data are representative for the whole vegetation period, annual fluxes of NO and NO 2 were estimated. Annual NO emission into the atmosphere amounted to 87 mg N m -2 y -1 (0.87 kg ha -1 y -1 ), annual NO 2 deposition into canopy monoliths amounted to 1273 mg N m -2 y -1 (12.73 kg ha -1 y -1 ). Apparently, the uptake of atmospheric nitrogen by the wheat field from NO 2 deposition is about 15 times higher than the loss of nitrogen from NO emission. It can therefore be assumed that even in rural areas wheat fields are a considerable sink for atmospheric nitrogen. The annual sink strength estimated in the present study is ca. 12 kg N ha -1 y -1 . The possible origin of the NO emitted and the fate of atmospheric NO 2 taken up by the wheat canopy monoliths are discussed.
    Keywords: dynamic chamber ; gas exchange ; nitrogen dioxide ; nitric oxide ; wheat canopy monolith
    ISSN: 0032-079X
    E-ISSN: 1573-5036
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