围栏封育对农牧交错区沙化草地植物群落影响--以宁夏盐池为例

Influence of Fencing on Vegetative in Crop-grazing Crisscross Area of China——Taking Yanchi County,Ningxia as an Example

封育措施是一种主要的草场恢复和重建的措施。通过对半干旱沙地老封育、新封育和对照区的比较分析,量化了不同封育措施下植被变化。对三种封育措施群落组成和生物多样性的分析结果表明:封育改变了群落的组成成分并增加了生物多样性;同时对群落植物的生活型、饲用价值分析及样方相似性指数计算结果则显示,老封育(>10a)的群落植物逐渐向多年生发展,各植物种分布的空间异质性显著提高,放牧价值开始降低,而对照区则明显处于一种非平衡的稳定状态。从3种措施植被的盖度、高度、生物量和饲用价值来看,老封育区均低于新封育区和对照区,表明长期封育不利于促进并提高草场的放牧利用价值。

Fencing has been applied as a main measure for revegetation all over the world. By comparing the results of old, new fenced areas and control the vegetation variations under three different exclusion measures were quantified in this recearch. The analysis results for community species component and plant diversity showed that fencbecoming perennity and unpalatability, and showed highly spatial heterogeneity of plant species distribution, whereas community for comparative exclusion was under stable non - equilibrium condition. In the view of vege- tation coverage, mean height, biomass, palatability of plant composition, community for old exclusion had lower than new and comparative exclusion which proved partly that long- term exclusion can not increase grazing values for semi -arid rangeland.