Yan Li
Xinjiang Institute of Ecology and Geography, CAS

Started from 2002, we have been studying the response of desert plants to precipitation variations in Zhungaer Basin, with spatial scales ranged from foliage, individuals, layer to community. The main conclusions are:
(1) Major dominant species exhibit strong physiological stability
Facing strong variation in precipitations, major dominant species in this temperate desert such as Tamarix spp, Haloxylon ammodendron, Reaumuria soongonica, exhibited strong physiological stability. Their response mainly occurred at individual scale: with leaf/root or shoot/root ratio adjusted, physiological activities at leaf scale was maintained at normal level.
(2) The effect of snow-cover to annuals limited to its seedling stage
After manipulating the thickness of snow-cover, the density, species richness, and individual size of the annuals were monitored. The results revealed that, snow thickness altered the plant density, but not the species richness. Furthermore, high density reduced the size of the plants. As a result, primary productivity is not affected by snow-cover thickness.
(3) Desert plant community has high water use efficiency in wet year
In dry year, plant coverage of annuals is very low, thus precipitation falls down mainly on the bare soil and is wasted. In wet year, large amount annual plants emerges, more precipitation can be used by plants instead of being wasted. Thus, in desert plant community, water use efficiency is lower in dry year but higher in wet year.
Overall, desert plant exhibited very strong ability against precipitation variation and seems well prepared for climate change.