Research

The response of plateau ecosystems on Qinghai-Tibetan Plateau to global climate change is more sensitive than plain ecosystems. its behavior may predict global change and influence the global climate moreover. Therefore, the studies on the behavior of the alpine meadow ecosystem are relatively important. In this paper, using the direct measure (CV, E) of data from system variables, which are observed at the Haibei Alpine Meadow Ecosystem Research Station, we discuss the stability of the natural ecosystem. The results of stability measure suggest that the net primary production of the ecosystem was more stable (CV=13.18%) than yearly precipitation(CV=16.55%) and yearly mean air temperature(CV=28.82%), and that the net primary production was quite insensitive to the precipitation (E=0.0782) and to the air temperature (E=0.1113). In summary, the Haibei alpine meadow ecosystem is much stable.

Comparing stability between the alpine meadow ecosystem and five natural grassland ecosystems in Israel and southern African also indicates that the Haibei alpine meadow ecosystem is relative stable. The alpine meadow ecosystem with relatively simple structure has higher stability, which show that community stability is not only correlated with biodiversity and community complicity but correlated with environment stability. The average oscillation cycles of 3 to 4 years are actually existed in the fluctuations of yearly precipitation, yearly mean air temperature, the net primary production and consumer populations at the Haibei natural ecosystem. This is a highly stable mode analogous to neutrally stable cycles. The higher stability of the Haibei ecosystem is resulted from stable environment and the evolution of the ecosystem adapting environment.