Abstract:

The plots were selected from sandy land in Inner Mongolia Grassland Ecosystem Research Station (IMGERS). The effects of sandy land micro-topography on plant functional groups, species diversity and species composition were studied by testing biomass, coverage, density and height, and so on. The results showed that micro-topography had effects on species composition, community characteristics and species diversity. The total biomasses of tested plots were ordered as Steep > Bottom of the slope > Sunny slope > Top of the slope; Shannon-Weaver index of the bottom of the slope was significantly lower than steep, sunny slope and the top of the slope (P<0.05); Patrick richness index and Pielou evenness index of steep, sunny slope and the bottom of the slope were significantly higher than the top of the slope (P<0.05). The main functional groups of the bottom of the slope were perennial forb; the main functional groups of steep were shrub, subshrub and perennial grasses; the main functional groups of sunny slope were shrub, subshrub, perennial grasses and annual or biennial herb; the main functional groups of the top of the slope were perennial grasses and annual or biennial herb.

Key words: Biomass, Diversity, Enclosure, Functional groups, Micro-Topography

摘要：

以内蒙古锡林郭勒盟中国科学院生态系统定位站长期围封的沙地样地为研究对象,通过测定植物群落的生物量、盖度、密度和株高等相关指标,探讨群落的物种组成、生物多样性等对沙地微地形变化的响应情况,以阐明沙地微地形对植被的影响机理.结果表明:沙地微地形对生物量、生活型、功能群及生物多样性均有影响.其中,总生物量顺序为:阴坡 > 坡底 > 阳坡 > 坡顶;植物多样性指数坡底显著低于阴坡、阳坡和坡顶(P < 0.05),而阴坡、阳坡和坡顶三者之间无显著差异;丰富度指数和均匀度指数阴坡、阳坡和坡顶显著高于坡底,阴坡、阳坡和坡顶三者之间差异不显著;坡底以多年生杂类草占优,阴坡以灌木、半灌木及多年生禾草为主,阳坡以灌木、半灌木、多年生禾草及一、二年生植物为主,坡顶以多年生禾草和一、二年生草本植物为主.

关键词: 生物量, 多样性, 围封, 功能群, 微地形