TY - JOUR
T1 - Summer rain pulse size and rainwater uptake by three dominant desert plants in a desertified grassland ecosystem in northwestern China
AU - Cheng, Xiaoli
AU - An, Shuqing
AU - Li, Bo
AU - Chen, Jiquan
AU - Lin, Guanghui
AU - Liu, Yuhong
AU - Luo, Yiqi
AU - Liu, Shirong
N1 - Funding Information:
The work partially was supported by the National Basic Research Projects (2002CB111504), the Major Project of the National Natural Science Foundation of China (39990490), and the Chinese Academy of Sciences through CAS’s Bairen Program (G. Lin). We thank Mr Yaosheng Huang, Dongsheng Ma and Yuanwu Zhuo for their assistances in the field sampling and lab analysis. Jim Clark, James Ehleringer, and Amy Concilio provided constructive and valuable suggestions for improving the quality of an earlier version of this manuscript.
PY - 2006/5
Y1 - 2006/5
N2 - To examine the different effects of rain pulse size on uptake of summer rains by three dominant desert plants in field conditions of desertified grasslands on the Ordos Plateau of northwestern China, we studied relationships between precipitation event size and rainwater uptake using stable isotopes of hydrogen in plant and soil water. Four natural precipitation events that represented precipitation sizes of 5.3, 8.3, 13.3, and 65.3 mm in the summer were chosen for the experiment. The perennial grass Stipa bungeana, the shrub Artemisia ordosia, and the herb Cynanchum komarovii - the dominant species in the communities - were compared for their use of summer rains with different pulse sizes based on the changes in the hydrogen isotope ratios (δD) of their stem water 7 days following each natural rain event. We found that S. bungeana and C. komarovii took advantage of shallow water sources derived from small (<10 mm) rain events, A. ordosia took advantage of deeper soil water recharged by large (>65 mm) rain events, and C. komarovii relied primarily on rain events of intermediate (10-20 mm) size. These different responses to rain pulses among species suggested that more frequent small rain events will promote the dominance of S. bungeana and C. komarovii, medium-sized events will facilitate development of C. komarovii, and large events will advance A. ordosia in this community. The rainwater utilization patterns of the three species would allow the coexistence of S. bungeana and A. ordosia or the coexistence of A. ordosia and C. komorovii in various successional serals following the disturbances. With an increase in variability of summer rain pulse size as predicted by climate change models, we expect that the structure of this community will undergo significant change in the future. Altered precipitation regimes, especially in combination with anthropogenic-related disturbances such as over-grazing, are likely to accelerate rates of degradation in northwestern China.
AB - To examine the different effects of rain pulse size on uptake of summer rains by three dominant desert plants in field conditions of desertified grasslands on the Ordos Plateau of northwestern China, we studied relationships between precipitation event size and rainwater uptake using stable isotopes of hydrogen in plant and soil water. Four natural precipitation events that represented precipitation sizes of 5.3, 8.3, 13.3, and 65.3 mm in the summer were chosen for the experiment. The perennial grass Stipa bungeana, the shrub Artemisia ordosia, and the herb Cynanchum komarovii - the dominant species in the communities - were compared for their use of summer rains with different pulse sizes based on the changes in the hydrogen isotope ratios (δD) of their stem water 7 days following each natural rain event. We found that S. bungeana and C. komarovii took advantage of shallow water sources derived from small (<10 mm) rain events, A. ordosia took advantage of deeper soil water recharged by large (>65 mm) rain events, and C. komarovii relied primarily on rain events of intermediate (10-20 mm) size. These different responses to rain pulses among species suggested that more frequent small rain events will promote the dominance of S. bungeana and C. komarovii, medium-sized events will facilitate development of C. komarovii, and large events will advance A. ordosia in this community. The rainwater utilization patterns of the three species would allow the coexistence of S. bungeana and A. ordosia or the coexistence of A. ordosia and C. komorovii in various successional serals following the disturbances. With an increase in variability of summer rain pulse size as predicted by climate change models, we expect that the structure of this community will undergo significant change in the future. Altered precipitation regimes, especially in combination with anthropogenic-related disturbances such as over-grazing, are likely to accelerate rates of degradation in northwestern China.
KW - Desert plant
KW - Desertified grasslands
KW - Hydrogen isotopic composition
KW - Rain pulse size
KW - Summer precipitation
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U2 - 10.1007/s11258-005-9047-6
DO - 10.1007/s11258-005-9047-6
M3 - Article
AN - SCOPUS:33745056220
SN - 1385-0237
VL - 184
SP - 1
EP - 12
JO - Plant Ecology
JF - Plant Ecology
IS - 1
ER -