滇中不同群落结构云南松林的水文作用

研究结果表明,在3类不同群落结构的云南松林中,调节和涵养水分、保持水土的能力均以复层林最好,禾草一云南松林居中,疏林最差;林冠截留率分别为13.4％,9.3％和7.9％;地表枯枝落叶层的最大持水量分别为65.8t/ha,46.6t/ha和6.7t/ha;年平均冲刷量分别为0.015t/ha,0.088t/ha和0.452t/ha,径流深分别为4.32mm,15.59mm和85.57mm;径流系数分别为0.60％,2.16％和11.85％。此外,长期受人为干扰、结构简单的疏林地土壤含水量及表土层中有机质、全N、速效态P、K元素含量都明显地低于其它两类林地。本文最后提出,为了提高森林水文效益,一方面要营造具有多层结构的云南松针阔混交林,另一方面也要注意保护林下地被植物和枯枝落叶。

Preliminary Study on Hydrologic Function ofDifferently Structured Pinus yunnanensis Forestsin Central Yunnan Province

Canopy interception, soil erosion, water and nutrient conditions of soil and the water retaining capacity of litter, under differently structured Pinus yunnanensis forests in central Yunan Province were studied. The results showed significant differences of hydrologic function among three differently structured P, yunnanensis forests. In the multi-storeyed forest, the mean annual percentage of canopy interception was 13.4% of the rainfall and was 9.3% and 7.9% in the grass-P.yunnanensis forest and the open forest; maximum water retention was 65.8t/ha, 46.6t/ha and 6.7t/ha respectively, the mean annual soil losses were 0.015t/ha, 0.088t/ha and 0.452t/ha respectively, the mean annual surface water runoff were 4.32mm, 15.59mm and 85.57mm respectively, and the coefficients of surface runoff were 0.60%, 2.16% and 11.85% respectively. The soil water content and the content of organic matter, total N and available P, K in the surface soil of the open forest were lower than that of the other forests. From these results we can conclude that, to increase the hydrologic function of the forests, mixed forests of P,yunnanensis and of broad-leaved, multi-storeyed trees should be planted. Moreover,attention should be paid to protection of cover plants and litter.