黄土高原丘陵沟壑区植被恢复重建后的物种多样性研究

黄土高原丘陵沟壑区是我国物种多样性研究相对较薄弱的地区。目前关于该区植被恢复重建后的物种多样性研究尚未见报道。研究该区植被恢复重建后的物种多样性对退化生态系统的植被恢复重建具有重要的指导意义。本文选取6个物种多样性指数对纸坊沟流域主要的天然及人工群落物种多样性进行了研究，研究发现：天然灌木林物种多样性最高，均匀度最大，人工乔木林和天然草本的物种多样性及均匀度接近，人工灌木林的多样性和均匀度最小。人工林纯林（包括纯乔木林、纯灌木林及单一乔灌混交林）具有很强的抵抗其它乔灌物种入侵和定居的能力，对林下草本也有很强的控制能力。因此，要建造一个具有较高物种多样性的群落，在建造初期就要选择多物种混交，并注意初值密度。

The Research of Species Diversity after the Vegetation Restoration in Loess Hilly Region

The research on species diversity in Loess hilly region is relatively less,and no research on species diversity after vegetation restoration has been reported in this region. But the research on species diversity has guidance to vegetation rebuilding. according to the research on the natural and artificial communities by six indexes of species diversity in Zhifanggou watershed. We found that the natural bush communities have the highest index of the diversity and the evenness, and the artificial arbor communities have no distinct difference with that of the natural herb, and the artificial bush communities have the lowest index of diversity and evenness. The artificial communities can prevent other bush and arbor from invading and resident. It is important to plan a rational density at the beginning of planting for building a community with high species diversity.