川西亚高山针叶林植物群落演替对生物学特性的影响

Influence of Plant Community Succession on Soil Biological Properties During Subalpine Coniferous Plantation Rehabilitation in Western Sichuan

通过对川西亚高山针叶林人工重建过程中土壤微生物数量、酶活性及其与土壤养分性状的关系研究表明,云杉人工成熟林土壤微生物数量、酶活性明显低于云杉人工幼林地,也低于同龄的次生阔叶林地,人工云杉林随着林龄的增加土壤肥力严重退化。土壤微生物数量、酶活性与土壤有机质、全N、全P和碱解N等养分指标呈显著相关关系,土壤生物学指标能较好地反映土壤肥力状况。解决当前人工成熟云杉林土壤退化的主要措施应因地制宜地进行抚育间伐,改善林地的微生态条件,尽量避免营造针叶纯林,建议营造针阔混交林。

Number of soil microorganism and enzyme activity and their relationship with soil nutrients were studied during subalpine coniferous plantation rehabilitation in western Sichuan. The results showed that the number of soil microorganism, enzyme activity of the mature spruce plantation were significantly lower than those of the young spruce plantation and secondary broad-leaved forest. Soil fertility degraded greatly with increasing of spruce plantation age, which was mainly affected by forest micro-environment. There were significant correlation between the amounts of soil microorganisms and soil enzyme activities and soil organic matter, total N, total P, alkali-hydrolyzable N and available K. Therefore soil biological index can be used as evaluation index of soil fertility. Inorder to accelerate the course of plant restoration and rehabilitation, the strategy and measures were put forward, including application of thinning rationally for existing dense plantations and establishment of mixture forest of coniferous and broad-leaved trees for new plantations, which would create good forest micro-environment for plant growth.