不同配置模式毛竹林水土流失特征

选取安吉县毛竹纯林、毛竹—杨桐混交林、毛竹—杨桐—萱草混交林作为研究对象,对大气降雨和3种林分中的地表径流量、土壤流失量、养分流失量(总氮和总磷)进行了研究。结果表明:(1)安吉县6—10月份降雨量呈明显波动趋势,降雨量为6.0~106.0mm。根据降雨强度划分等级安吉县25场降雨划分为小雨、中雨、大雨和暴雨。(2)安吉县暴雨对应的径流系数相对较高,其次为大雨。3种林分中毛竹纯林径流系数最大,毛竹—杨桐—萱草混交林最小。(3)3种林分径流系数、土壤流失量和养分流失量变化趋势基本一致,均呈明显波动趋势。6月和8月径流系数、土壤流失量和养分流失量相对较大。(4)降雨量与地表径流回归方程和地表径流与土壤流失量回归方程均为线性回归方程,说明降雨量与地表径流、地表径流与土壤流失量均呈线性关系。

Characteristics of Soil and Water Loss on Bamboo Forest Lands

Bamboo pure forest,Bamboo Cleyera japonica mixed forest and Bamboo Cleyera japonica-Hemerocallis mixed forest were selected in Anji County.Atmospheric precipitation,surface runoff,soil loss and nutrient loss (total nitrogen and total phosphorus) were studied.The results showed that:(1) rainfall showed a trend of fluctuations from June to October in Anji County,rainfall is 6.0～106.0 mm.According to the rainfall intensity grade,rainfall in Anji County was divided into light rain,moderate rain and heavy rain;(2) runoff coefficient corresponding to the rainstorm was relatively high,followed by heavy rain,runoff coefficient was the largest in three kinds of forest lands,Bamboo-Cleyera japonica-Hemerocallis mixed forest was minimum;(3) the trend of the runoff coefficient,soil loss and nutrient loss of 3 kinds of stands were basically same,all of which showed a trend of fluctuation,in June and August,the runoff coefficient,soil loss and nutrient loss were relatively large;(4) the regression equation of rainfall and surface runoff and the regression equation of surface runoff and soil loss were all linear regression equations,which showed that there was the linear relationship between rainfall and surface runoff,surface runoff and soil loss,respectively.