Desertified lands are widespread throughout the world in arid and semi-arid zones (Dregne, 2002), many owing their condition to human over-exploitation such as mining, clear-cutting, over-grazing, etc. Thus, many countries have made great efforts to control desertification by planting and fencing to restore vegetation.

The process of vegetation restoration on desertified land can be viewed as succession. Species diversity is the critical property of plant communities and is of considerable significance in the study of succession, since variations in diversity are presumably correlated with the stability of various biotic and abiotic components of ecosystems (MacArthur, 1955; Leigh, 1965). Plant species diversity can be the driver of early succession in abandoned agricultural fields. The diversity of plant species present at certain stages of succession may affect the course of succession (Van der Putten et al., 2000). Biodiversity has become an important measure for the evaluation of ecosystems (Magurran, 1988 A.E. Magurran, Ecological Diversity and its Measurement, Princeton University Press, Princeton, NJ, USA (1988) (415pp).Magurran, 1988), although the role of species diversity in ecosystem functioning is disputed (Schulze and Mooney, 1994; Patrick, 1997). Research on species diversity along successional gradients is necessary for understanding the mechanisms of recovery via succession on mobile sand dunes in severely degraded lands. Such knowledge is needed for combating desertification and enhancing the sustainability of agro-ecological systems.

So by examining patterns and dynamics of plant species diversity along a successional gradient in sand dunes, the objectives of this paper are (1) to describe succession characteristics during the process of vegetation restoration in a severely degraded sandy land, and (2) to provide useful lessons for practices of revegetation in semi-arid regions, especially in desertified sandy areas.

Species diversity influences plant community structure and function. This paper examines the patterns and dynamics of species diversity along a chronosequence of vegetation recovery on sand dunes in a semi-arid region to assess the probability of vegetation recovery via succession, and provides some implications for revegetation practices in this region. Species richness and diversity indices gradually increased with succession, except for a decline in the community of 18 years, which is attributed to the strong dominance of Artemisia halodendron. In each stage of the restoration process, there was a dominant species with particular life history traits which contribute to the dominance of this species. Species replacement and habitat changes were the main drivers of succession, while plant species and community succession drove the process of vegetation recovery. Results showed that restoration via succession holds promise for vegetation recovery and desertification control within protected, fenced enclosures.