米亚罗亚高山草甸冬春两季土壤动物群落特征的比较

Comparisons of soil animal community characteristics of subalpine meadow between winter and spring in Miyaluo

土壤动物是陆地生态系统的重要组成部分,不仅对物质循环具有重要的作用,还对土壤质量或健康状况起指示作用。为了掌握川西北亚高山草甸土壤动物群落的特征,于2007年11月和2008年4月对米亚罗地区的亚高山草甸土壤动物群落进行了调查。共捕获大型土壤动物320只,隶属2门4纲15类(目),优势类群为双翅目幼虫、鞘翅目幼虫和鞘翅目成虫;中小型土壤动物6 081只,隶属4门7纲16类(目),优势类群为线虫类。土壤动物的群落结构在冬春两季有较大差异,土壤动物的类群数和个体数在冬春两季节间无显著变化(P>0.05);多样性指数中,仅有中小型土壤动物的丰富度指数在春冬两季出现显著下降(P<0.05);大型和中小型土壤动物在垂直分布上具有明显的表聚性,季节变化不显著(P>0.05)。与我国北方草原的土壤动物群落相比,川西北米亚罗亚高山草甸的土壤动物群落不仅在物种组成上有较大的差异,而且个体密度较高。

Soil animals are an important component part of the terrestrial ecosystem, and they could be used as indicator species to monitor and evaluate soil quality and health with effects on material cycles. The investigations were conducted on soil animal communities of the subalpine meadow in Miyaluo area, located in northwestern Sichuan, in November of 2007 and April of 2008. A total of 320 large-sized soil animals, belonging to 2 phyla, 4 classes and 15 groups or orders, and 6,081 middle-small-sized soil animals, belonging to 4 phyla, 7 classes and 16 groups or orders, were collected. The dominant groups of the large-sized soil animal community were Diptera larvae, Coleoptera larvae and Coleoptera adult while that of the middle-small-sized soil animal community was Nematoda. The community structures of soil animals changed significantly between the winter and spring, but the groups and individual numbers between the two seasons did not change significantly （P〉0.05）. The Margalef index of the middle-small-sized soil animal community significantly declined from winter to spring （P〈0.05） but the other diversity indexes did not change significantly. The number of groups or individual soil animals decreased significantly （P〈0.05） with soil depth but the differences between the seasons of spring and winter were not significant. The species compositions of soil animal communities in subalpine meadow ecosystems in northwestern Sichuan have higher individual densities that are different from those of the grassland ecosystems in the north of China.