西江中下游生态公益林对降水的截留分配效应研究

为了评估生态公益林涵养水源服务功能，选择德庆县三叉顶自然保护区生态公益林，定位观测2006年6月～2007年6月100次大气降水事件的截留分配效应。结果表明，观测期内降水总量为1317．60mm，林冠截留量、树干茎流量和穿透水量分别是318．37，87．85和911．38mm，林冠截留率、茎流率和穿透率分别为24．16％，6．67％和69．17％。林外降水量大于1．31mm时才能观测到穿透雨，林外降水量达到3．0mm时才开始有树干茎流出现。林冠截留量、树干茎流量和穿透量与降水量均呈正相关，相关系数序分别为0．7888，0．9577和0．9659；林冠截留率与林外降水量呈负相关，而树干茎流率和穿透率呈正相关，相关系数尺。分别为0．8356，0．8034和0．8742。

Redistribution Effects of Tree Canopy of Ecological Public Welfare Forest at Middle-lower Reaches of Xijiang River

The experiment was conducted in the ecological public welfare forest at middle-lower reaches of Xijiang River in order to evaluate its service function in water preserving capability. Total 100 precipitation cases from June 2006 to June 2007 were monitored, also the redistribution and interception effect of the tree canopy on precipitation was analyzed. The results indicated that total precipitation were 1 317.60 ram, canopy interception, step-flow, throughfall of the forest were 318.37, 87.85, 911.38 mm, which account for 24. 16%, 6.67%, 69.17% of the total precipitation, respectively. Only when precipitation was over 1.3 mm and over 3.0 mm through fall and Stem-flow could be recorded respectively. Canopy interception, step-flow, throughfall was positively correlated with precipitation amount, and correlation coefficients were 0. 788 8, 0. 957 7, and 0. 965 9 respectively. Through canopy interception rate was negatively related with precipitation amount, stern flow rate and through fall rate of the forest were positively correlated with precipitation amount, and correlation coefficient are 0. 835 6, 0.803 4, 0. 874 2 respectively.