Contrasting drivers of belowground nitrogen cycling in a montane grassland exposed to a multifactorial global change experiment with elevated CO 2 , warming, and drought.

Autor: Maxwell TL; Division of Terrestrial Ecosystem Research, Department of Microbiology and Ecosystem Science, Center of Microbiology and Environmental Systems Science, Vienna, Austria.; INRAE, Bordeaux Sciences Agro, ISPA, Villenave d'Ornon, France., Canarini A; Division of Terrestrial Ecosystem Research, Department of Microbiology and Ecosystem Science, Center of Microbiology and Environmental Systems Science, Vienna, Austria., Bogdanovic I; Division of Terrestrial Ecosystem Research, Department of Microbiology and Ecosystem Science, Center of Microbiology and Environmental Systems Science, Vienna, Austria., Böckle T; Division of Terrestrial Ecosystem Research, Department of Microbiology and Ecosystem Science, Center of Microbiology and Environmental Systems Science, Vienna, Austria., Martin V; Division of Terrestrial Ecosystem Research, Department of Microbiology and Ecosystem Science, Center of Microbiology and Environmental Systems Science, Vienna, Austria., Noll L; Division of Terrestrial Ecosystem Research, Department of Microbiology and Ecosystem Science, Center of Microbiology and Environmental Systems Science, Vienna, Austria., Prommer J; Division of Terrestrial Ecosystem Research, Department of Microbiology and Ecosystem Science, Center of Microbiology and Environmental Systems Science, Vienna, Austria., Séneca J; Division of Terrestrial Ecosystem Research, Department of Microbiology and Ecosystem Science, Center of Microbiology and Environmental Systems Science, Vienna, Austria., Simon E; Division of Terrestrial Ecosystem Research, Department of Microbiology and Ecosystem Science, Center of Microbiology and Environmental Systems Science, Vienna, Austria., Piepho HP; Institute of Crop Science, University of Hohenheim, Stuttgart, Germany., Herndl M; Agricultural Research and Education Centre Raumberg-Gumpenstein, Irdning-Donnersbachtal, Austria., Pötsch EM; Agricultural Research and Education Centre Raumberg-Gumpenstein, Irdning-Donnersbachtal, Austria., Kaiser C; Division of Terrestrial Ecosystem Research, Department of Microbiology and Ecosystem Science, Center of Microbiology and Environmental Systems Science, Vienna, Austria., Richter A; Division of Terrestrial Ecosystem Research, Department of Microbiology and Ecosystem Science, Center of Microbiology and Environmental Systems Science, Vienna, Austria., Bahn M; Department of Ecology, University of Innsbruck, Innsbruck, Austria., Wanek W; Division of Terrestrial Ecosystem Research, Department of Microbiology and Ecosystem Science, Center of Microbiology and Environmental Systems Science, Vienna, Austria.
Jazyk: angličtina
Zdroj: Global change biology [Glob Chang Biol] 2022 Apr; Vol. 28 (7), pp. 2425-2441. Date of Electronic Publication: 2022 Jan 10.
DOI: 10.1111/gcb.16035
Abstrakt: Depolymerization of high-molecular weight organic nitrogen (N) represents the major bottleneck of soil N cycling and yet is poorly understood compared to the subsequent inorganic N processes. Given the importance of organic N cycling and the rise of global change, we investigated the responses of soil protein depolymerization and microbial amino acid consumption to increased temperature, elevated atmospheric CO 2 , and drought. The study was conducted in a global change facility in a managed montane grassland in Austria, where elevated CO 2 (eCO 2 ) and elevated temperature (eT) were stimulated for 4 years, and were combined with a drought event. Gross protein depolymerization and microbial amino acid consumption rates (alongside with gross organic N mineralization and nitrification) were measured using 15 N isotope pool dilution techniques. Whereas eCO 2  showed no individual effect, eT had distinct effects which were modulated by season, with a negative effect of eT on soil organic N process rates in spring, neutral effects in summer, and positive effects in fall. We attribute this to a combination of changes in substrate availability and seasonal temperature changes. Drought led to a doubling of organic N process rates, which returned to rates found under ambient conditions within 3 months after rewetting. Notably, we observed a shift in the control of soil protein depolymerization, from plant substrate controls under continuous environmental change drivers (eT and eCO 2 ) to controls via microbial turnover and soil organic N availability under the pulse disturbance (drought). To the best of our knowledge, this is the first study which analyzed the individual versus combined effects of multiple global change factors and of seasonality on soil organic N processes and thereby strongly contributes to our understanding of terrestrial N cycling in a future world.
(© 2021 The Authors. Global Change Biology published by John Wiley & Sons Ltd.)
Databáze: MEDLINE
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