黄土丘陵沟壑区退耕还林工程对植被恢复影响的研究--以陕西吴旗县为例

在对吴旗县乔木林、灌木林和草原群落野外调查的基础上，对其植被恢复及植被恢复与水土流失的关系进行了定量分析，结果表明，在吴旗县这样的自然地理条件下，通过退耕还林、封山禁牧，植被完全可以得到恢复，完全可以控制水土流失的发生。在自然恢复初期，植物群落将以草原地带性植被为主，并可以恢复到稳定阶段。三种植被群落在植物多样性方面差异并不大，草原群落的物种多样性和群落均匀度要略小于乔木林和灌木林群落。

Study on the Effects of the Project of Returning Cropland to Forest on Re-vegetation in Loess Hilly Region--Take Wuqi County in Shaanxi as an Example

On the basis of field investigation about the arbor, shrub and steppe communities in Wuqi county, the authors quantitatively analyzed the vegetation recovery and the relationship between vegetation recovery and soil erosion. The results showed that on the natural geographical conditions of Wuqi county, vegetation can be recovered by returning cropland to forest and grazing prohibition in mountains to control soil erosion, On the initial stage of natural recovery, plant vegetation is mainly grassland zonal vegetation which can be recovered to stable stage. Differences of the plant diversity of these three vegetation communities are little, and the species diversity and evenness of steppe community are less than those of arbor and shrub communities.