Details
| Original language | English |
|---|---|
| Pages (from-to) | 8-18 |
| Number of pages | 11 |
| Journal | Applied soil ecology |
| Volume | 41 |
| Issue number | 1 |
| Publication status | Published - Jan 2009 |
| Externally published | Yes |
Abstract
Overgrazing increasingly affects large areas of Inner Mongolian semi-arid grasslands. Consequences for ecosystem functions and, in particular, for the decomposition as a key process of ecosystem carbon (C) and nitrogen (N) cycling are still unclear. We studied the effects of grazing on shoot and root decomposition with the litter bag method in a long-term grazing exclosure (UG79), a moderate winter grazed (WG) and a long-term heavily grazed site (HG). We separated the effects of local environmental factors and litter quality as altered by grazing. Growing seasons of average and very low precipitation allowed us to study the effect of inter annual rainfall variability on decomposition. Grazing-induced differences in environmental factors of the three studied grassland sites had no effect on decay rates of shoot and root dry mass. Also differences in litter quality among the grazing sites were not reflected by root decomposition dynamics. The accelerated shoot decay at site HG could not clearly be linked to litter quality parameters. Shoot decay rates were more or less constant, even under very dry conditions. This indicates the possibility of photodegradation (solar UV-B radiation) to control aboveground decomposition in this semi-arid ecosystem. By selecting the best predictors of root decomposition from regression analysis, we found that soil water content was the best parameter explaining the dynamics. Net N immobilization was generally not detected during the decay process of shoot and root. It is likely, when root decomposition is strongly reduced in dry periods, shoot decomposition becomes relatively more important for nutrient cycling. A separate analysis of shoot and root decay dynamics is required in order to describe C and N cycling in this semi-arid grassland. The grazing impact on C and N fluxes through decomposition of plant material likely exhibits a strong interaction with seasonal rainfall pattern.
Keywords
- Inner Mongolia, Litter bag, N release, Nitrogen and carbon cycling, Steppe
ASJC Scopus subject areas
- Environmental Science(all)
- Ecology
- Agricultural and Biological Sciences(all)
- Agricultural and Biological Sciences (miscellaneous)
- Agricultural and Biological Sciences(all)
- Soil Science
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
In: Applied soil ecology, Vol. 41, No. 1, 01.2009, p. 8-18.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Effects of grazing and rainfall variability on root and shoot decomposition in a semi-arid grassland
AU - Giese, Marcus
AU - Gao, Ying Zhi
AU - Zhao, Ying
AU - Pan, Qingmin
AU - Lin, Shan
AU - Peth, Stephan
AU - Brueck, Holger
N1 - Funding Information: This work was part of the Sino-German research group MAGIM (Matter fluxes in grasslands of Inner Mongolia as influenced by stocking rate) financed by the Deutsche Forschungsgemeinschaft (DFG), Sa-359/30-1, FG 536, and by the National Nature Science Foundation of China (NSFC, 40471077). We gratefully acknowledge IMGERS and the farmer Guo Shu Ping. We would like to thank two anonymous reviewers and the section editor for their helpful comments.
PY - 2009/1
Y1 - 2009/1
N2 - Overgrazing increasingly affects large areas of Inner Mongolian semi-arid grasslands. Consequences for ecosystem functions and, in particular, for the decomposition as a key process of ecosystem carbon (C) and nitrogen (N) cycling are still unclear. We studied the effects of grazing on shoot and root decomposition with the litter bag method in a long-term grazing exclosure (UG79), a moderate winter grazed (WG) and a long-term heavily grazed site (HG). We separated the effects of local environmental factors and litter quality as altered by grazing. Growing seasons of average and very low precipitation allowed us to study the effect of inter annual rainfall variability on decomposition. Grazing-induced differences in environmental factors of the three studied grassland sites had no effect on decay rates of shoot and root dry mass. Also differences in litter quality among the grazing sites were not reflected by root decomposition dynamics. The accelerated shoot decay at site HG could not clearly be linked to litter quality parameters. Shoot decay rates were more or less constant, even under very dry conditions. This indicates the possibility of photodegradation (solar UV-B radiation) to control aboveground decomposition in this semi-arid ecosystem. By selecting the best predictors of root decomposition from regression analysis, we found that soil water content was the best parameter explaining the dynamics. Net N immobilization was generally not detected during the decay process of shoot and root. It is likely, when root decomposition is strongly reduced in dry periods, shoot decomposition becomes relatively more important for nutrient cycling. A separate analysis of shoot and root decay dynamics is required in order to describe C and N cycling in this semi-arid grassland. The grazing impact on C and N fluxes through decomposition of plant material likely exhibits a strong interaction with seasonal rainfall pattern.
AB - Overgrazing increasingly affects large areas of Inner Mongolian semi-arid grasslands. Consequences for ecosystem functions and, in particular, for the decomposition as a key process of ecosystem carbon (C) and nitrogen (N) cycling are still unclear. We studied the effects of grazing on shoot and root decomposition with the litter bag method in a long-term grazing exclosure (UG79), a moderate winter grazed (WG) and a long-term heavily grazed site (HG). We separated the effects of local environmental factors and litter quality as altered by grazing. Growing seasons of average and very low precipitation allowed us to study the effect of inter annual rainfall variability on decomposition. Grazing-induced differences in environmental factors of the three studied grassland sites had no effect on decay rates of shoot and root dry mass. Also differences in litter quality among the grazing sites were not reflected by root decomposition dynamics. The accelerated shoot decay at site HG could not clearly be linked to litter quality parameters. Shoot decay rates were more or less constant, even under very dry conditions. This indicates the possibility of photodegradation (solar UV-B radiation) to control aboveground decomposition in this semi-arid ecosystem. By selecting the best predictors of root decomposition from regression analysis, we found that soil water content was the best parameter explaining the dynamics. Net N immobilization was generally not detected during the decay process of shoot and root. It is likely, when root decomposition is strongly reduced in dry periods, shoot decomposition becomes relatively more important for nutrient cycling. A separate analysis of shoot and root decay dynamics is required in order to describe C and N cycling in this semi-arid grassland. The grazing impact on C and N fluxes through decomposition of plant material likely exhibits a strong interaction with seasonal rainfall pattern.
KW - Inner Mongolia
KW - Litter bag
KW - N release
KW - Nitrogen and carbon cycling
KW - Steppe
UR - http://www.scopus.com/inward/record.url?scp=57549118736&partnerID=8YFLogxK
U2 - 10.1016/j.apsoil.2008.08.002
DO - 10.1016/j.apsoil.2008.08.002
M3 - Article
AN - SCOPUS:57549118736
VL - 41
SP - 8
EP - 18
JO - Applied soil ecology
JF - Applied soil ecology
SN - 0929-1393
IS - 1
ER -