Abstract: In order to explore the species diversity and biomass allocation of desert grassland communities,this study used a sample method to study the relationship between species diversity of typical desert grassland communities around Urumqi for the above-ground,below-ground and litter biomass. The results showed that:The species composition of typical desert grassland communities around Urumqi was single,and there were significant differences in the average height,coverage and density among the communities(P<0.05). All communities showed that below-ground biomass>above-ground biomass>litter biomass;in the 0~50 cm soil layer,the below-ground biomass was higher in 0~5 cm,and was increased with the depth of the soil layer,the below-ground biomass gradually decreased,but the Haloxylon ammodendron community was just the opposite,as the depth of the soil layer increased,the below-ground biomass showed a trend of first increasing and then decreasing. The result of establishing the optimal curve model showed that the above-ground biomass has an exponential function relationship with the below-ground biomass,and the fitting equation was:y=231.375×e0^{.003 3x} (R²=0.714 8),indicating that the desert grassland community exhibited an allometric growth pattern around Urumqi. There was a linear relationship between litter and below-ground biomass,and the fitting equation was:y=13.818x+259.812(R²=0.616 1). The relationship between the above-biomass and species diversity on the colony showed that they have a significant negative nonlinear correlation,and the correlation form conforms to the single-peaked curve,and the corresponding equation was:y=-5.210 4x²+0.004 5x+0.369 9(R²=0.307 1,P<0.01). There was a very significant linear correlation between the below-biomass and species diversity of the colony,and the corresponding equation was:y=3.735x+0.678 2(R²=0.543 4,P<0.05). The research results will provided a basic data for the restoration of degraded desert grasslands,biodiversity protection,the maintenance and restoration of ecosystem function.

Key words: Desert grassland, Community, Species diversity, Biomass

摘要： 为探讨荒漠草地群落物种多样性及生物量分配，本研究采用样方法对乌鲁木齐市周边典型荒漠草地群落物种多样性与生物量的关系进行研究。结果表明：乌鲁木齐周边典型荒漠草地群落物种组成单一，群落平均高度、盖度、密度、生物量呈现显著性差异(P<0.05)；0～50cm土层中，群落地下生物量除梭梭群落均随着土层深度增加而逐渐减小，梭梭群落则呈先增加后降低的趋势；植物群落呈异速生长模式，拟合方程为：y=231.375×e^{0.003 3x}(R²=0.714 8)；凋落物生物量与地下生物量之间呈线性关系，拟合方程为：y=13.818x+259.812(R²=0.616 1)；地上生物量与物种多样性之间呈单峰变化曲线，对应方程为：y=-5.210 4x²+0.004 5x+0.369 9(R²=0.307 1，P<0.01)，群落地下生物量与物种多样性之间关系表现出极显著的线性相关，对应方程为：y=3.073 5x+0.678 2(R²=0.543 4，P<0.05)。本研究结果可为退化荒漠草地的恢复及生物多样性保护、生态系统功能维持与恢复提供基础数据。

关键词: 荒漠草地, 群落, 物种多样性, 生物量