重庆缙云山4种林地林下枯落物储量及其持水特性研究

通过对重庆缙云山针阔叶混交林、阔叶林、楠竹林和灌木林4种典型植被类型林下枯落物及其持水特性分析研究,结果表明:林下枯落物储量大小为灌木林>阔叶林>针阔混交林>楠竹林,其中半分解层和分解层的总储量大于未分解层储量.缙云山自然保护区4种不同植被类型下枯落物持水特征曲线具有明显不同,持水能力为灌木林>针阔混交林>阔叶林>楠竹林.在浸泡前2h内持水量变化极大,2h以后变化量变小,各层持水量浸泡8h后均基本达到饱和.未分解层枯落物持水量小于半分解层分解层枯落物的持水量,枯落物各层持水量与浸泡时间之间的关系符合Q=alnt+b关系.4种不同植被类型林下枯落物吸水率大小为针阔混交林>灌木林>阔叶林>楠竹林,枯落物各层吸水速率与浸泡时间存在V=ktⁿ关系.在枯落物持水作用较强的前2h内,其吸水速率最快的为灌木林,达到22.208mm/h.

Reserves and Water Capacity Characteristics of Four Kinds of Litters in Jinyun Mountain

To survey and analyze the litter amount and water retention characteristic,the litter is under the 4 typical vegetations(mixed broadleaf-conifer forest,broad-leaved forest,Phyllostachys pubescens forest and shrub forest) in Jinyun Mountain.The results indicate that litter amount is shrub forest broad-leaved forest mixed broadleaf-conifer forest Phyllostachys pubescens forest.The amount of half-decomposed layer and decomposed layer is more than undecomposed layer.To study the process of water retention capacity of litter,the curves of litter water retention characteristic are different among 4 typical vegetations in Jinyun Mountain.The water-holding ability of the litters is shrub forest mixed broadleaf-conifer forest broad-leaved forest Phyllostachys pubescens forest.It greatly changes in 2 hours,and has little change after 2 hours.The water-holding amount of every layer reaches the largest after 8 hours and the water-holding amount of undecomposed layer is less than half-decomposed layer and decomposed layer.Regression analyses show that Q=alnt+b is the relationship of the water-holding amount of every layer and soaking time.The water absorption rate of 4 kinds of vegetations is mixed broadleaf-conifer forest shrub forest broad-leaved forest Phyllostachys pubescens forest.The relationship of the water absorption rate and soaking time is V=ktⁿ.The water absorption rate of shrub forest is the largest in the first 2 hours of water retention capacity of litter,and it can reach 22.208mm/h.