摘要：Artificial enclosure has been an important and practical measure widely used to restore vegetation inthe ecologically degraded area. In this study, using a standard plot investigation method, we investigatedthe changes in biomass and species diversity of the plant communities in the desertified grasslandlocated in Ningxia Autonomous Region, China, after enclosure for 0, 5, 15 and 25 years with fencesmade up of cement piles and barbed wires, with a complete exclusion of interferences from anyactivities including grazing. We also analysed the factors driving the changes in these parameters.The results showed that with the increase in the enclosure duration, the soil electrical conductivity andnutrient contents were significantly increased but the thickness of biological crust in the deserted areawas not changed regularly and the soil pH values were changed only slightly. Furthermore, while nosignificant differences in plant biomass, species abundance and -diversity were seen, significantdifference in -diversity was seen among different enclosure years. Principal component analysisshowed the significant differences in species compositions in the deserted grassland among variousenclosure years. The redundancy analysis revealed that the available nitrogen, available potassium,soil organic carbon and soil electrical conductivity were the major factors affecting the plant speciescompositions in the deserted area in the studied region. These findings can be of practical significancefor formulating the measures to effectively curb the deterioration of ecological environment in grassland.
