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| Titel |
Effects of interactive global changes on soil N-fluxes in managed grassland |
| VerfasserIn |
Evi Deltedesco, Merle Gerding, Maria Naynar, Sophie Zechmeister-Boltenstern, Markus Gorfer, Michael Bahn, Erich M. Pötsch, Markus Herndl, Katharina M. Keiblinger |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250149622
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| Publikation (Nr.) |
 EGU/EGU2017-13989.pdf |
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| Zusammenfassung |
| Climate projections for the next decades expect a significant increase in air temperature,
atmospheric CO2 concentrations and the frequency and intensity of extreme weather events.
The impact of individual environmental factors (warming and elevated CO2) on
biogeochemical cycles of ecosystems is moderately well studied. However, the quantification
of the impact of these combined environmental changes on N-cycling functions of
ecosystems and their biogeochemical feedbacks to the climate system is still fraught with
uncertainty, both in terms of magnitude and the interactions.
The aim of the present study is the evaluation of the response of warming, elevated CO2
concentrations and their combined effect on N-gas emissions, microbial community structure
and function in a managed grassland site. This project is implemented in a complex field
experiment in a mountain region (Raumberg-Gumpenstein) and consists of a factorial
approach. Individual and combined effects of air temperature (ambient, warming
of 1.5 and 3˚ C) and atmospheric CO2-concentrations (ambient, +150 and +300
ppm) on N-pools and N-gas emissions is examined and related to soil microbial
processes.
In order to achieve our objectives, soil was sampled in autumn 2016. Intact soil cores
were incubated at constant temperature to analyze N2O, NOx and NH3 emissions in a lab
incubation experiment. Simultaneously, soil samples were taken to examine different N pools
(DON, Nmic, NH4+ and NO3−). In addition the abundance of ammonia oxidizing bacteria
and archaea (amoA) together with expression levels of involved N-cycling target genes (nirK,
nirS, norB and nosZ) was evaluated.
Variation in N-fluxes was observed and will be discussed. This research provides new
insights on microbial processes in response to factorial climate change effects, and will
enable us to evaluate changes through non-linear and non-additive effects of multiple factors
of climate change. |
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