川西亚高山不同密度缺苞箭竹对土壤生物学特性的影响

在缺苞箭竹-紫果云杉原始林下,研究了缺苞箭竹密度变化过程中土壤微生物、酶活性及其与土壤养分性状的相互关系.结果表明,随密度的增大,土壤微生物数量及酶活性逐渐降低,林地枯枝落叶层分解缓慢,贮量逐渐增加.各密度间全N,K及速效N,K库贮量无显著差异,但全P及速效P库贮量随密度的增大显著降低.微生物数量、酶活性与土壤有机质、全N、全P、碱解N和速效P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.建议适当稀疏高密度缺苞箭竹,防止林地土壤退化,促进川西针叶林群落演替更新和大熊猫食物基地建设.

Influence of Subalpine Fargesia denudate with Different Density on Soil Biological Properties in Western Sichuan

Number of soil microorganism and enzyme activity and their relationship with soil nutrients were investigated with the density change of subalpine Fargesia denudate under the primitive Fargesia denudata-Picea purpurea forest in Western Sichuan.The results showed that with the density increasing,the number of soil microorganism and enzyme activity decreased which led to the decomposed rate of the forest floor decreased and the standing pool increased gradually.The storage of total and available P decreased significantly with the density increasing but there had no notable change for the storage of total and available N and K among different densities.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 P.Therefore soil biological index can be used as evaluation index of soil fertility.In order to avoid soil degeneration and accelerate subalpine coniferous plantation succession and building the food base for panda,keeping suitable Fargesia denudate density would be a good measure for subalpine Fargesia denudata-Picea purpurea forest management.