人工林的土壤结构质量研究--以长江上游桤柏人工混交林为例

长江上游生态建设中,典型区营林10–20年的人工混交林有纯林化、衰败退化的演化趋势。本文以长江上游地区川中丘陵的人工林典型土壤为例,并以长江上游未受人为不良干扰的贡嘎山天然林土壤为对照,研究了人工林退化的土壤结构质量问题及其防治措施。结果表明:人工林土壤结构质量远不如天然林土壤。指出长江上游人工林土壤结构质量的退化,是人工林退化的重要影响因素。人工林土壤结构退化的主要原因是人为干扰,缺乏保护和科学管理。主要防治对策是:封禁生态修复和采取恢复枯枝落叶层、施有机肥等措施。

Structural quality of soil in plantation: a case study on the mixed plantation of Alnus cremastogyne and Cupressus funebris in upper reaches of Yangtze River

In process of ecological construction in typical region of upper reaches of Yangtze River, China, the mixed plantations at the ages of 10-20 present a trend to be pure forests and degeneration. Soil samples including stratified soil and total soil were taken from 4 typical profiles in the mixed plantation of Alnus cremastogyne and Cupressus funebris in Yanting County in central Sichuan, China. Soil indices of the plantation were compared with those of natural forest in Gongga Mountain in the same region. The results revealed that structural qual-ity of soil in plantation was significantly lower than that in natural forests. The degradation of structural quality of soil in plantation was one of key factors for plantation degeneration. The degradation causes of structural quality of soil were analyzed. Aanthropogenic disturbance and absence of effective protection and scientific management are the main reason for degradation of structural quality of soil in plantation. The main countermeasures, e.g. forest reservation, ecological rehabilitation, litter horizon rebuilding as well as organic fertilizer application, were proposed to improve the structural quality of soil in plantation.