Efficacy of exclosures in conserving local shrub biodiversity in xeric sandy grassland, Inner Mongolia, China

Abstract

This study investigated the abundance and frequency of occurrence of all shrub species present in the standing vegetation at four sites, including a 5-year exclosure (protected grassland) and three adjacent unprotected grazing sites that had been subjected to different levels of degradation (light, moderate and severe), in xeric sandy grassland of Inner Mongolia for three growing seasons. Shrub species abundance, richness, and diversity in the exclosure were compared with three unprotected sites to determine the efficacy of exclosure on shrub biodiversity conservation. Using the data set, the responses of individual shrub species to level of grassland degradation were also examined by means of detrended correspondence analysis (DCA). Individual shrub species responded differently to degradation level. From individual species responses we identified three main response types. The first type is represented by Artemisia holodendren showing a positive response to degradation level. The second type is represented by Lespedeza davurica, Hedysarum fruticosum, and Caragana microphylla indicating a negative response to degradation level. The third type included Ceratoides arborescens and Artemisia frigida following a different response pattern from the first two response types. Exclosure effects varied remarkably with different shrub species. The results suggest that it is generally necessary to apply an exclosure to the severely degraded grassland while light to moderate grazing disturbance is helpful for the maintenance of shrub species diversity. These findings are important for understanding how grassland degradation affected the population demography of shrub species and for developing appropriate management strategies for conservation of degraded shrub vegetation.

Parent Publication

• Proceedings: Shrubland dynamics -- fire and water

Citation

Li, Feng-Rui; Zhou, Zhi-Yu; Zhao, Li-Ya; Zhang, Ai-Sheng; Kang, Ling-Fen. 2007. Efficacy of exclosures in conserving local shrub biodiversity in xeric sandy grassland, Inner Mongolia, China. In: Sosebee, Ronald E.; Wester, David B.; Britton, Carlton M.; McArthur, E. Durant; Kitchen, Stanley G., comps. Proceedings: Shrubland dynamics -- fire and water; 2004 August 10-12; Lubbock, TX. Proceedings RMRS-P-47. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. p. 163-169.