生态环境学报Issue(3)：398-405,8.
围封6年对温带典型草原坡地物种多样性及其与地上生物量的关系的影响
Species richness within a six-year slope exclosure in a temperate grassland and its relationship with aboveground biomass
摘要
Abstract
Our experiment was conducted within a six-year slope exclosure in a typical Stipa krylovii grassland of Taips County, Inner Mongolia. By sampling the species abundance and aboveground biomass both inside and outside (normal grazed, or control)the exclosure, we analyzed the patterns of community structure and aboveground biomass, and explored the effects of exclosure on community structure, species richness, and aboveground biomass. The results showed that the spatial pattern of the species diversity and cover of the functional groups are similar. The species richness and aboveground biomass increased significantly with decreasing slope position, showing that the spatial variation of species richness and ecosystem function had the same trend. Species richness was significantly lower in the exclosure than the control because of reduced annuals and grass species. However, the aboveground biomass of the grazed control is significantly lower than the exclosure treatment due to the development of subshrubs and shrubs inside the exclosure. The experiment results strongly implied that overgrazing or over protection can lead grassland degradation. However, the degradation directions of the two management are distinctly different: Overgrazing suppressed the grass and shrub biomass, leaving opportunities for annuals. On the other hand, over protection give the changes for shrubs and subshrubs to proliferation. The human activities including grazing and cutting increased the growth of grazing-tolerant and unpalatable plants, to some extent. The coverage and biomass of annual were higher outside the fence, so as to the frequency. For example, the frequency ratio of inside to outside was as low as 13:71, and Lepidium sativum and Salsola collina only existed outside. The regression of aboveground biomass on species richness showed that the biomass increased with species richness both inside and outside of the exclosure, but the inside exclosure seems has much larger slope coefficient than the outside. This study demonstrated that long term grazing prohibition may not be the right way to restore the arid and sub-arid grassland, in order to maintain sustainable usage of grassland, appropriate moderate grazing should be carefully planned according the local climate and soil conditions.关键词
围封/放牧/植物功能群/物种丰富度/地上生物量Key words
exclosure/grazing/plant function type/species richness/aboveground biomass分类
农业科技引用本文复制引用
徐粒,高琼,王亚林..围封6年对温带典型草原坡地物种多样性及其与地上生物量的关系的影响[J].生态环境学报,2014,(3):398-405,8.基金项目
国家自然科学基金项目 （）
