鼎湖山人为干扰下马尾松林水文生态功能

在鼎湖山马尾松林中，林外降水量年平均为2209．0mm，其中83．8％－84．5％的降水休中在春夏两季，而秋冬两季仅占15．5％－16．2％。林外降水到达冠重新分配，穿透雨占了82．7％，林冠截留17．2％，茎汉0．15％。林外降水进入该生态系统后，34％以径流形式流出，其余的通过蒸散形式返回大气层。林冠截留率随林外降水量的增加而减少，但随着降水的增大，其降幅逐渐减小。茎流率的变化与林冠截留率相似，单株茎流量与胸径和枝下高的大小呈显著的直线关系（P＜0．01），但与林冠大小关系不明显，径流仅发生在每年的4－10月份，年平均径流率为0．34。

Ecohydrological Functions of a Human-disturbed Pinus massoniana Forest in Dinghushan Biosphere Reserve

The study of ecohydrological functions of a Pinm massoniana,forest with anthropogenic disturbance was carried out in Dinghushan Biosphere Reserve, Guangdong Province, during 1997-1999. Mean annual rainfall in this pine forest was 2 209.9 mm, with 83.8%-84.5% of rainfall in spring and summer, and only 15.5%-16.2% of rainfall in autumn and winter. Of the rainfall on forest canopy, throughfall comprised 82.7%, canopy interception 17.2%, and stemflow 0.15%. There was 34% of the rainfall as runoff, and the remainder evapo-transpired. Canopy interception decreased with increase in rainfall, but such decrease was lowered with the increasing rainfall. Similar feature was observed for stemflow. Stemflow of individual tree showed linear relation with diameter breast height and with stem height under branch (p<0.01), but did not relate with the size of forest canopy. Runoff appeared onlyduring April to October, with mean annual runoff rate 0.34.