鼎湖山不同演替阶段的森林土壤水分动态

运用中子水分仪监测了鼎湖山土壤水分数据，分析了鼎湖山不同演替阶段林地的土壤水分动态及其特征，探讨了温室效应对自然群落演替下土壤水分的影响.研究表明，鼎湖山不同林型林地土壤水分变化具有明显的差异，但它们的总体变化规律基本一致，即季风林、混交林、针叶林同一土层土壤储水量具有相似的变化趋势，从地表往下，土壤各层储水量呈下降趋势.随着森林的演替，林地土壤持水能力增强，且逐渐集中分布在根系比较密集的土壤上层.从各土层间的相关性来看，季风林最强，其次为针叶林，混交林最小.根据各季节土壤储水量变化的特点，鼎湖山土壤水分变化的季节动态大致分为3个阶段：土壤水分亏损期（1-3月）、补偿期（4-9月）和相对稳定期（10-12月）.

Soil Water Storage of Three Forest Types in Different Succession Stage in Dinghushan

Based on soil moisture data measured by hydroprobe moisture (CPN503DR),the dynamics and characteristics of soil water storage of three forest types were analysed in different succession stage in Dinghushan.Soil water storage differed greatly for different forest types,but having similar changing tendencies,i.e,decreasing with the soil depth.The soil water storage in monsoon evergreen broad-leaved forest was much higher than that in coniferous and broad-leaved mixed forest,and the storage in mixed forest was higher than that in coniferous forest.With the forests' succession,the soil water storage capability increased,and distributed randomly in the upper layers,where the root density was more intense.This indicated that the forest ecosystems had their own adaptable mechanisms to the environment.The maximum coefficients between forest soil layers were found in monsoon evergreen forest,and the minimum values in coniferous forest.The seasonal dynamics of soil water storage in Dinghushan can be divided into three stages:soil water consumption stage (from Jan. to Mar.),compensating stage (from Apr. to Sept.) and stable stage (from Oct. to Nov.).