山地荒漠草原植物群落多样性与环境因子动态关系研究

在时间截面和生境截面下 ,对植物群落多样性动态特征与环境因子进行灰色关联分析。结果表明 ,山地荒漠草原中与植物群落多样性关系较大的环境因子为地形、土壤水分、土壤有机质以及土壤盐分。其中地形因子决定了山地内水、热、养分的再分配 ,因此是主要因子。多样性与环境因子关系模式符合干旱环境特征。具有长期放牧史的草地植物群落多样性动态滞后于环境因子变化 ,体现出一年生植物与环境波动的适应性对群落动态影响的特征。由于山地植物群落多样性对生态系统功能 (水分涵养、土壤养分积累、生产力等 )具有积极作用 ,因此干旱山地生态系统恢复有赖于提高植物群落多样性。干旱条件下对一年生植物种子及植株生长发育影响较大的因子 ,是影响群落动态的主要因子 ,例如土壤水分含量。时间序列上群落多样性与环境因子关系较为复杂 ,因为放牧干扰 ,环境波动直接影响群落结构和物种消长动态。

Studies on Dynamic Relationship Between Plant Diversity and Environmental Factors in the Mountain-desert Grassland

At different sections of time and topography, the dynamic relationship between plant diversity and its environmental factors was analyzed by the grey association analysis. Xiangshan Mountain area in Ningxia is the core habitat of a special goat-Zhongwei goat,where the species diversity and its dynamic characteristics are affected strongly by several factors, such as topography, water contents, organic matters, and salinity of the soil. The micro-topography is the most main factor for in the mountains for it determines the water, hot and nutrients reassignment in the area. The relation pattern of the diversity and its environmental factors is accords with the characteristics of droughty climate. In the long-term grazing grassland, especially in mountains, plants diversity change slower than the environmental factors. It is indicated that the annual plants' adaptability affects the dynamic of the plant diversity strongly. The restoration of the ecosystem is determined by the increasing of biodiversity for there are positive effects between diversity and ecosystem functions (maintaining water and soil, soil nutrient accumulated, productivity etc.) in that region. The main factor, which affects the dynamic of the plants diversity, is the soil water content that affects the growing of the annual plant and its seed evidently. In the serial of time, the relation between diversity and environmental factors is more complex, the reason includes grazing interference, environmental fluctuating, and all that disturb the community structure and species change.