Abstract: Ramsar Wetlands of International Importance are significant for biodiversity protection as roosting, breeding or wintering sites of endangered species. The driving factors of wetland endangered species richness were analyzed by using the spatial autoregressive model at the scale of 300, 600 and 1200 km. The results indicated that human interruption hypothesis has the highest explanatory strength among all hypotheses for endangered species richness of Ramsar sites, followed by energy hypothesis and habitat heterogeneity hypothesis. The endangered species richness of Ramsar sites is significantly positively correlated with annual range of temperature and habitat size function, and significantly negatively correlated with GDP per capita. The results are helpful to deeply understanding the driving factors of endangered species richness on global scale as well as to endangered species protection of global Ramsar sites.

Key words: grassland evapotranspiration, upper reach of the Heihe River, weighting lysimeter, diurnal variation