贡嘎山暗针叶林生态系统林冠截留特征研究

Interception capability of dark coniferous forest ecosystem in Gongga Mountain.

林冠截留能力是反映森林与水关系的一个重要指标 .该研究充分考虑林冠结构特征与降雨特性 ,采用机械布样与林分叶面积指数相结合方法 ,观测了贡嘎山不同演替阶段的暗针叶林群落林内降雨 .结果表明 ,林内降雨量与林外降雨量线性相关 ,其回归系数可用来估计林冠蓄水蒸发系数 ,而截距可以用来估计林冠蓄水容量 ;林冠截留量与林外降雨量呈幂函数关系 .在原有预测季节或生长季林冠截留模型基础上 ,引入单场降雨平均强度 ,用叶面积指数修正林冠透水系数 ,建立新的林冠截留概念模型 。

Interception capability is a key indicator to denote the relationship of forest and hydrology.In this paper,more attentions are paid to the crown structure and precipitation features,thus throughfalls have been observed by the method of fixed square\|plot arrangement in different types of dark coniferous forest communities at four successive stages referenced by LAI.Results show that throughfall is linearly correlated to rainfall outside of stands,and the aggression coefficient can be used to assess evaporation ability of water stored in canopy,and the interception of the formula can be used to assess water storage in canopy.There is typical power function relation between interception and rainfall.Based on the model which can predict the interception of a season or a growing season,other than single rainfall,and revising the throughfall coefficient by LAI,indexes of average individual rainfall intensity have been introduced in a new interception conception model directly,which can effectively predict the interception capability of the dark coniferous forest ecosystem in the upper reaches of the Yangtze River.