干旱区生态环境知识资源中心

Applying a combination of classical and geostatistical methods, we examined the patterns and changes of vegetation in the degradation processes of sand grasslands (fixed, semi-mobile and mobile sandy land) in Horqin sandy land. Our results showed that: (1) vegetation cover, species richness and diversity, biomass and litter decreased with the degradation of sandy grasslands; (2) there were particular predominant species with particular, life history traits which contribute to the dominance of community at each degradation. stage. Geostatistical analysis revealed that the spatial structured variance accounted for the larger proportion of total sample variance in vegetation cover and species richness at study scale. The effective ranges of vegetation cover did not exceed 14m, while species richness varied from 20.5 m to 183.00 m, which reveals that vegetation cover had a higher spatial variability than richness in sandy grassland degradation. These results suggest that the degree of vegetation variability at field scale can be used as an index for indicating the extent of sandy grassland degradation. The pattern and variability of vegetation are related to the changes of the dominant species. The changes in vegetation variability may in turn influence vegetative succession and restoration process of degraded sandy grassland ecosystem.