A comparative study on water conservation capacity of five main forest types

Based on the data from fixed sample plots of main forest types in Lianxiahe small watershed of Three Gorge Reservoir (Area) of Changjiang River,water conservation capacity had been studied.The results showed that there is a binary linear regression for both throughfall and stemflow to precipitation quantity and precipitation intensity, and a power regression for canopy interception to rainfall.The relative interception ranges from 16.34% to 27.43% on an average of 22.15%. Under the same rainfall,the decrease order of canopy interception in the different forest types is coniferous and broad-leaved mixed forest,masson pine forest,coniferous forest and cypress forest. The biomass of litter layer in different forest ecosystems varies from 10.52 to 21.90 t·hm~(-2) on an average of 17.61 t·hm~(-2),and the decrease order of the biomass is coniferous and broad-leaved mixed forest,masson pine forest,cypress forest,coniferous forest and shrubbery .The maximum water holding capacity of litter formed in the different forest ecosystems varies from 2.66 to 4.19 mm on an average of 3.48 mm, and the decrease order is cypress forest,coniferous forest,coniferous and broad-leaved mixed forest,masson pine forest and shrubbery. The water holding capacity of non-capillary porosity of soil layer in different forest ecosystems varies from 34.68 to 44.16 mm on an average of 40.35 mm,and the decrease order is cypress forest, coniferous and broad-leaved mixed forest,coniferous forest, masson pine forest and shrubbery. The total interception of rainfall in different forest ecosystems varies from 377.6 to 494.6 t·hm~(-2) on an average of 446.56 t·hm~(-2), the decrease order is cypress forest,coniferous and broad-leaved mixed forest, coniferous forest, masson pine forest and shrubbery.