不同密度大叶相思人工林林下植物和土壤特性

对3种密度大叶相思人工林的林下植物和土壤特性进行了研究.结果表明,大叶相思人工林林下植物的总覆盖度为:低密度林分(1 667株/hm2)＞中密度林分(4 444株/hm2)＞高密度林分(10 000株/hm2).林下植物总生物量呈现:低密度林分＞中密度林分＞高密度林分,低密度林分的灌木生物量最高,中密度林分的草本生物量最高.低、中、高密度林分的林下灌木层的Simpson多样性指数分别为0.679,0.935和0.708,草本层分别为0.837,0.678和0.789;灌木层的Shannon-Wiener多样性指数分别为1.657,0.535和1.171,草本层分别为0.904,1.228和1.064;灌木层的Pielou均匀度指数分别为0.691,0.333和0.654,草本层的分别为0.504,0.886和0.594.除有效P外,低密度和中密度林分的土壤特性优于高密度林分.

Understory Plants and Soil Characteristics in Acacia Auriculiformis Plantations with Different Densitie

Understory plants and soil characteristics of Acacia auriculiformis plantations with three densities were studied.Results showed that the total coverage degrees of understory plants were in the order of lowdensity stand(1 667trees/hm²)> middle-density stand(4 444trees/hm²)> high-density stand(10 000trees/hm²).The total biomass of understory plants were in the order of low density stand> middle-density stand>high-density stand,and the shrub biomass of low-density stand and the grass biomass of middledensity stand were the greatest among the three stands.In the low,middle and high density stands,Simpson diversity indexes for shrub layer were 0.679,0.935and 0.708,and for grass layer,0.904,1.228and1.064;Shannon-Wiener diversity indexes for shrub layer were 1.657,0.535and 1.171and for grass layer,0.904,1.228and 1.064;and Pielou evenness indexes for shrub layer were 0.691,0.333and 0.654,and for grass layer,0.504,0.886and 0.594,respectively.Except the available P,the soil characteristics of the low and middle density stands were better than those of high-density stand.