宁夏荒漠草原不同群落生物多样性与生物量关系及影响因子分析

摘要

Impact factors and relationships between plant biodiversity and biomass of different communities of desert steppe in an unmodified condition were determined using biodiversity indices,soil physical and chemical factors and assessment of aboveground and underground biomass.The results showed that species richness and diversity varied similarly in different communities.Exponential relationships between aboveground biomass and underground biomass showed that the desert steppe community displayed allometric growth patterns.The re-sponse of community richness to aboveground biomass was unimodal,while that to underground biomass was linear.Underground biomass was positively correlated with surface litter.Soil moisture,soil organic carbon, total nitrogen and available nutrients also contributed to underground biomass while soil moisture and soil or-ganic carbon greatly contributed to aboveground biomass.Soil microbial biomass,soil carbon and nitrogen had a significant influence on community diversity indices.%通过测定生物多样性各指标、地上－地下生物量、枯落物量、土壤理化因子以及土壤微生物量碳氮，研究了自然状态下荒漠草原6种群落生物多样性与生物量的关系及其影响因子。结果表明：荒漠草原不同群落丰富度、均匀度与多样性指数变化趋势一致；地上生物量与地下生物量呈指数关系，表明荒漠草原群落呈异速生长模式；生物多样性与地上生物量呈单峰曲线，与地下生物量呈线性关系，初步表明荒漠草原不同群落地上部分种间作用、资源利用程度基本一致，生物多样性抑制了地上生物量，但并没有抑制其地下生物量；地表枯落物与地下生物量呈极显著的线性相关关系（P ＜0．01），初步表明了地下生物量更加依赖于地表枯落物。相关分析表明，荒漠草原生物多样性指数和生物量影响因子存在明显差异，自然条件下土壤含水量、有机碳、全氮以及有效养分对地下生物量贡献较大，土壤含水量和有机碳对地上生物量贡献较大，土壤微生物量碳和氮对群落多样性指数贡献较大。