中文摘要：

利用土壤溅蚀杯方法测定了西双版纳地区单层、两层和多层人工橡胶林林冠下的土壤溅蚀率以及林外空旷地的土壤溅蚀率。实验结果表明,单层、多层和两层人工橡胶林的土壤溅蚀率分别为林外空旷地的1.55、1.30和1.05倍,表明3种不同橡胶林林冠的穿透水侵蚀力均大于林外空旷地的降水侵蚀力,尤其是单层橡胶林。分析认为,林下土壤溅蚀率和穿透水侵蚀力与林冠结构有着极其密切的关系,尤其是冠层高度、覆盖度。高度较小、覆盖度较大的冠层对控制林地土壤溅蚀和穿透水侵蚀力方面具有明显的正面效应。因此在营造人工橡胶林的水土保持系统时,应在林下种植覆盖高、植冠低的经济作物,从而形成有效减弱穿透水侵蚀力的林冠结构,同时应有效保护、管理林地的地表枯落物层,以减少雨滴对地表的侵蚀。

英文摘要：

Landscape in Xishuangbanna,SW China changed dramatically during the past three decades when massive tropical rainforest lands were converted to rubber plantation lands,with potentially critical ecological and environmental consequence.To study the impacts of different canopy of rubber plantation on soil particle detachment by rainfall,splash erosion rate（SER） was investigated in a single layer canopy rubber plantation（SRP）,a two layers canopy rubber plantation（TRP） and a multiple layers canopy rubber plantation（MRP） by conducting field experiments with Ellison-type splash cups.The results of the measurements under forest canopy showed that the SER in the SRP,MRP and TRP were separately 1.55,1.30 and 1.05 times higher than that in the open conditions,indicating that the erosivity of throughfall under the three canopy structural types of rubber plantation was higher than that in the open.This meant that protecting the soil from raindrop impact was not valid for the TRP,MRP and particularly the SRP.Based on this result,we proposed that only the litter layer played an important role in controlling splash erosion,and removal of the litter layer in these rubber forests stands was likely to produce higher erosion rates than open field.Furthermore,results also indicated that the erosivity of throughfall was highest in the SRP,followed by the MRP,and the lowest in the TRP,suggesting that the throughfall erosivity was strictly linked to the forest canopy structure,especially height and canopy cover.The implication of the results is that an important consideration in managing the rubber plantation may be the plantation of tea or other economic crops with high coverage and low height under that canopy,forming a canopy structure which is effective in decreasing throughfall erosivity and rainsplash erosion on the forest floor.