晋西黄土区林草复合系统草本植物多样性特征

Herbaceous plant diversity of silvopastoral system in the loess region of western Shanxi Province,northern China

以晋西黄土区刺槐-草地复合系统为研究对象,用移动窗口法判定复合系统边界,采用α多样性和β多样性分析复合系统草本植物多样性特征。结果表明:1)移动窗口法分析显示,在最小窗体单位(1m)为8时能够清晰地判定刺槐-草地复合系统边界,其影响域从林内4m到草地4m,总宽度为8m,草本植物样方间相似性的聚类分析结果与此一致;2)α多样性分析表明:草地物种最为丰富,林草边界植物分布最不均匀;3)β多样性分析表明:林地植物种类变化剧烈,说明林地的生境分异程度和物种被替代速率都较高。

The silvopastoral system boundary was studied using moving split-window approach in Robinia pseudoacacia forests and grassland system in the loess region of western Shanxi Province,northern China, and the characteristics of herbaceous plant diversity were analyzed by the method of α diversity and β diversity. The results showed that ： 1 ） the boundary of R. pseudoacacia forests and grassland system could be discriminated clearly when the window width reached 8 ,and the influencing range of the silvopastoral system was 8 m,i. e. ,from 4 m inside forestland to 4 m inside grassland,which was consistent with the result of hierarchical cluster for similarity index （SI） of quadrats ; 2） α diversity analysis showed that the species diversity in grassland was the highest, and there was the largest unevenness in the boundary of silvopastoral system; 3） β diversity analysis showed that the changes for forestland plant species were dramatic, indicating that the differentiation of woodland habitats was bigger and the rates of species being replaced were higher in forestland than in grassland.