人为干扰对典型草原土壤侵蚀影响的价值评价

Evaluation of the Impacts of Human Disturbances on Soil Erosion in the Typical Grassland

基于不同干扰条件下典型草原风洞试验的研究结果,计算了风蚀所造成的各种损失(养分、有机碳的损失及废弃地的形成等等),在此基础上,定量评价了人为干扰对土壤侵蚀过程的影响。研究结果表明,禁牧可以明显减小由风蚀所导致的草原生态系统的价值损失,而开垦和放牧则会增加其价值损失(包括速效养分、有机碳和废弃地形成)。总的来看,不同风速下不同生态系统的价值损失速率由大到小的排列顺序为:新开垦农田>农田>自由放牧草原>2003年禁牧草原>1987年禁牧草原;同时,风速越大不同干扰类型之间的价值损失差值越大。

Based on the results of wind channel experiments on the typical grassland under different human disturbances, the loss of nutrients, organic carbon and abandoned land were calculated, and on the basis of it, the impacts of human disturbances on soil erosion were evaluated quantificationally. The results showed that non--grazing reduced the value loss of typical grasslandsecosystem led by soil erosion remarkably, and farming and grazing could enhance it （including valid nutrients, organic carbon and abandoned land）. In sum, according to the value losses, the different human disturbances were ranked in a descending order as follows： farmland newly cultivated 〉 farmland〉 grazing grassland〉. non--grazing grassland since 2003〉non--grazing grassland since1987. Moreover, the differences among the different human disturbances increased as the wind speed increased.