林(竹)+草植被恢复初期地表径流及其养分流失特征

Characteristics of Surface Runoff and Its Nutrient Loss of Trees(Bamboo) + Grass Rehabilitation at an Early Stage

试验研究了华西雨屏区不同退耕还林植被配置模式的水土保持效能,通过分析降雨、地表径流、径流养分浓度和径流养分流失量得出:竹+草植被恢复模式在退耕3年后能有效地减少地表径流,侵蚀性降雨量及其降雨场次也明显少于农耕地,退耕地地表径流养分流失量和养分流失浓度也有所降低;幼龄桦木+牛鞭草植被系统功能表现不如竹+牛鞭草模式明显,需进一步加强林木培育管理;低径流量中径流的养分浓度大,应注意土壤系统结构培育和优化,尽量减少养分流失。

It tests and studies the efficiency of soil and water conservation in different configuration modes of returning land for farming to forestry in high precipitation region of west China.It educes that the vegetation rehabilitation pattern of bamboo + grass can effectively reduce the surface runoff after not planting crops for three years,erosive rainfall and number of rainfall events are notably less than that of the farmland and the quantity and concentration of surface runoff nutrient loss of returning land for farming are also somewhat reduced;the function of baby Birch + Tall Hemarthria vegetation system is not as obvious as the mode of bamboo + Tall Hemarthria and;the nutrient concentration of runoff in low runoff is higher and it shall pay attention to the structural incubation and optimization of soil system for reducing nutrient loss as less as possible.