桂东典型针阔林分凋落物及土壤持水特征

Comparison of water holding capacity of litter layer and soil layer of different forest types Taking Chinese fir pure forest, eucalyptus pure forest, masson pine pure forest, mixed forest of Chinese fir and Phoebe crenata as the research object, the water holding capacity of soil layer and litter layer of four forest types was compared and analyzed by fixed sample monitoring, ring knife sampling and soaking method. The results showed that the water holding capacity of soil layer and litter layer of the four stand types were different; The mixed forest of Cunninghamia lanceolata and Phoebe fortunei in the litter layer has the highest natural water content and the maximum storage capacity, which are 65.86% and 2.62 t/hm2 respectively; The eucalyptus pure forest and the Chinese fir pure forest have the maximum water capacity and the effective storage capacity, which are 4.77 t/hm2 and 2.01 t/hm2 respectively. In terms of total porosity index, the highest total porosity of pure Chinese fir forest is 35.85%, and the soil water holding capacity is the best. The soil layer storage capacity of all forest types accounts for more than 85%, and the effective storage capacity and comprehensive water capacity of pure Chinese fir forest are the largest, with the comprehensive water capacity of 49.56t/hm2,The results showed that the soil layer of typical coniferous and broad-leaved forest in eastern Guangxi is the main body of water conservation, and the litter layer plays an important auxiliary role in improving the water regulation function of soil.     

桂东典型针阔叶林分凋落物及土壤持水特征

本研究以杉木纯林、桉树纯林、马尾松纯林、杉木与火力楠混交林为研究对象，采用固定样地监测、环刀取样及浸泡法对4种林分类型土壤层和凋落物层的持水能力进行比较分析。结果表明：4种林分类型土壤层和凋落物层的持水能力均存在差异；杉木与火力楠混交林凋落物层自然含水率及最大拦蓄量最高，分别为65.86%及2.62 t/hm²；桉树纯林凋落物层最大持水量最高，杉木纯林凋落物层有效拦蓄量最高，分别为4.77 t/hm²和2.01 t/hm²。从土壤总孔隙度来看，桉树纯林的土壤总孔隙度最高，为37.04%。所有林分类型土壤层拦蓄量占比均超过95%，杉木纯林土壤层有效拦蓄量、综合持水量均为最大，其综合持水量达到47.24 t/hm²。研究表明，桂东地区典型针阔叶林分土壤层是水源涵养的主体，凋落物层对改善土壤的水分调节功能具有重要的辅助作用。