黄土高原退耕区不同林龄刺槐林下草本植物的多样性

通过典型样地调查,以空间序列代替时间序列方法,对不同林龄刺槐林下草本层的物种组成、丰富度指数、多样性指数、均匀度指数等进行分析。结果表明,刺槐林下草本植物科、属、种、株数、盖度及物种多样性均存在差异。林下植物种类丰富,群落整体更新情况良好,有草本植物67种,分属21科50属,以禾本科、菊科、豆科为主要科,用二次函数回归方程能较好地反映刺槐林龄与林下草本层多样性各指标间的关系。可见,不同林龄对刺槐林下草本植物多样性影响显著。

Diversity of Understory Herbaceous Species under the Robinia pseudoacacia with Different Ages of the Region of Returning Farmland to Forest in the Loess Plateau

Based on spatial sequence instead of temporal sequence method, indices of species diversity of the herb layers of the Robinia pseudoacacia were analyzed in Ansai County through typical plots investigation. Results showed that the community was in good condition in general, and the species were rich in the Robinia pseudoacacia plantation which included 67 species belonging to 21 families 50 genera. The main families included gramineae, compositae, and leguminosae. Families, genera, species, the number of individual plants, coverage and species diversity were different with the forest age, Regression analysis showed that the relationship between forest age and diversity index can be expressed well with quadratic function equation. It illustrates that forest age is the key factor in influencing the understory plant diversity of the Robinia pseudoacacia.