辽西地区水土保持林主要林分类型及结构特征分析

The major types of soil conservancy plantations in western Liaoning and structural features

对辽西地区现有几种主要的水土保持林林分类型进行了结构特征分析 ,结果表明 ,混交类型的水土保持林 ,其林分层次结构、生长情况均好于油松纯林 ,物种多样性指数高于纯林 ;林分生物量以油松—刺槐形成的乔木混交林最高 ,达 96 .5 5 0t hm2 ,比油松纯林提高 5 7.6 5 8t hm2 ;各类型混交林林地土壤理化性质有了很大的改善 ,混交类型林地土壤容重比纯林减小 0 .0 5～ 0 .2g cm3 、孔隙度提高 0 .76 %～ 3.4 5 %、有机质提高 0 .0 3%～ 0 .73%、全氮含量提高 0 .0 0 4 %～ 0 .0 36 % ,说明油松阔叶混交林在改善土壤理化性质方面起了重要作用 ;林分枯枝落叶量及持水量也明显高于油松纯林。

Analysis of structural features regarding several major types of soil conservancy plantations in western Liaoning was conducted. The results indicated that structures of layers and growth of mixed soil conservancy plantations were better than that of pure Pinus tabulaeformis stands, and biodiversity index was higher than that of pure stands; Biomass was highest(96.550t/hm 2)for mixed P. tabulaeformis and Robinia pseudoacacia stands,and elevated by 57.658t/hm 2 than that of pure P. tabulaeformis stands;Physical and chemical properties of soil in mixed stands were improved greatly, soil bulk density of mixed stands decreased by 0.05 ～0.2g/cm 3,porosity increased by 0.76%～3.45%,organic matter contents elevated by 0.03%～0.73%,total N contents enhanced by 0.004%～0.036% compared with that of pure stands respectively,which showed the important effects of mixed P. tabulaeformis and broadleaved stands on improving physical and chemical properties of soils; Biomass and water holding capacity were significantly higher than that of pure stands. It concluded that the mixed stands consisted of P. tabulaeformis and Robinia pseudoacacia were mixed types with optimal structures in western Liaoning.