封禁措施对云南金沙江流域主要林分的生态功能影响

Effects of Closing Measures on Ecosystem Function of Main Forest in Jinshajiang Watershed of Yunnan Province

通过封禁措施对林分的生态功能影响分析,认为:封禁后的云南松林和常绿阔叶林,在胸径或树高上都表现出明显的优势,且乔木上层盖度较大而均匀,优势种优势度明显,各优势种种群的年龄组成亦处于稳定状态,乔木树种多数更新良好,在垂直分布上呈连续分布,使整个群落在结构上处于稳定的状态;实施封禁措施的林分物种丰富度和多样性指数都明显高于未封禁的林分,且封禁时间越长,多样性指数越高。封禁后物种多样性指数总体上表现为常绿阔叶林>针阔混交林>针叶林>灌丛;实施封禁措施,土壤得到改良,通透性能较好,封禁后的腐殖质层厚度、土壤总孔隙度、毛管孔隙度比未封禁的高。在有机质、有效氮、有效磷方面,封禁的比未封禁的高,封禁的阔叶林比封禁的针叶林高。这体现了封禁后群落土壤具有较高的肥力,有利于群落生物生产力的提高,使群落生物生产力始终维持在较高水平,封禁后土壤疏松,持水能力增强,枯落物层多,对封禁前后的群落土壤最大持水量、枯落物最大持水量进行分析,得出封禁后林分的土壤最大持水量、枯落物最大持水量都高于未封禁的林分。

Effects of closing measures on ecosystem function of forest were analyzed. The results showed that the stability of community of Pinus yunnanensis forests and evergreen broad-leaved forest was improved by closing measures, which mainly included increasing of breast diameter and height, improving of conspicuousness and regeneration of most species of tree layer and continuity of its vertical distribution. Comparing with forest that of not being closed, the abundance and biodiversity of that of being closed were higher. With closing measures, the abundance and biodiversity increased rapidly. The order of the biodiversity was evergreen broad-leaved forest〉 mixed coniferbroad-leaved forest 〉 coniferous forest〉shrub. Soil quality was also improved by closing measures. The thickness of soil humus, soil total porosity, soil capillary porosity, soil organic matter, available nitrogen and available phosphorus were higher than that of not being closed, which indicated closing measures were contribute to improving soil fertility, productivity of community. The results also showed that soil maximum water holding capacity, litter maximum water holding capacity were higher than that of not being closed.