Zhao Ha-lin

PLANT PRODUCTION AND DIVERSITY AT DESERTIFICATION STAGES IN HORQIN SAND GRASSLAND REGION, CHINA

The selection of biodiversity indices has importance implications on the conclusions drawn from such studies (Cousins 1991). As simple and useful indices, species richness and the Shannon—Wiener (SW) indices have been widely used relative other indices for studying species diversity (Gough et al. 1994, Guo 1995). These two indices are used by many ecologists to describe species composition and function attributes of plant communities and to identify relationships between productivity and diversity (Hooper et al. 1997, Tilman et al. 1997). Due to the complexity, variation, and scale dependence of the traits of vegetation, there are many inherent uncertainties in the measurements and ultimate calculations of species richness and SW indices (Palmer 1988, Hegazy et al. 1998).