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| Titel |
Carbon and nitrogen dynamics of native Leymus chinensis grasslands along a 1000 km longitudinal precipitation gradient in northeastern China |
| VerfasserIn |
L. Ma, S. Yuan, C. Guo, R. Wang |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 11, no. 24 ; Nr. 11, no. 24 (2014-12-16), S.7097-7106 |
| Datensatznummer |
250117737
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| Publikation (Nr.) |
 copernicus.org/bg-11-7097-2014.pdf |
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| Zusammenfassung |
| Understanding how ecosystem carbon (C) and nitrogen (N) cycles respond to
the variability of precipitation can help us assess the effects of global
climate change on terrestrial ecosystem structure and function. We
investigated the contributions of aboveground biomass, litter, root, soil
and microbial communities to ecosystem C and N processes at 14 sites along a
1000 km precipitation gradient in native Leymus chinensis grasslands of northeastern China.
The results show that aboveground biomass C and N increased gradually, while
no significant regional trends in litter and root biomass were found with
increasing mean annual precipitation (MAP) along the gradient. Soil
respiration increased first and then decreased from the dry to mesic sites,
which could be ascribed to the relative changes in temperature, soil
fungal : bacterial biomass and N availability. Surprisingly, N mineralization varied
only slightly along the gradient, likely due to the decreases of soil
organic matter quality (i.e., C : N). Stepwise regression models indicated
regional soil C and N content positively correlated with MAP and clay
content. Overall, C and N sequestration increased 3.2- and 1.8-fold with
increasing MAP in terms of C and N storage in aboveground biomass, roots,
litter and soil. It was concluded from the current study that regional
precipitation variability strongly influences ecosystem C and N dynamics.
The ecosystem C and N sequestration are primarily modulated by annual
precipitation and soil texture, while the C and N turnover are largely
controlled by microbial community composition, temperature and soil quality
in L. chinensis grasslands across the large-scale precipitation gradient. |
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