放牧对短花针茅荒漠草原建群种与土壤团聚体特征的影响

发布时间：2018-04-12 06:43

本文选题：短花针茅 + 种群年龄　；参考：《生态环境学报》2017年06期

【摘要】：以内蒙古农业大学苏尼特右旗荒漠草原的放牧调控实验为平台,通过分析荒漠草原建群种种群结构及土壤团聚体特征,揭示放牧调控下荒漠草原短花针茅(Stipa breviflora)与沉积土壤的潜在联系。结果显示:(1)短花针茅幼龄与成年植株密度显著大于幼苗、老龄前期、老龄期密度;各年龄短花针茅种群密度、生物量均呈现重度放牧处理最高、适度放牧次之、重度放牧最低的规律;(2)短花针茅荒漠草原土壤团聚体分布受团聚体粒径及其与放牧强度的交互作用影响(P0.05);同一放牧处理中,100~250μm植物沉积团聚体含量最高,50μm与50~100μm团聚体含量次之、500μm团聚体含量最小;而裸地土壤团聚体以50μm团聚体含量最高;(3)50μm裸地土壤团聚体含量与50μm植物沉积土壤团聚体含量呈正相关(P0.05),而50μm植物沉积土壤团聚体含量与各年龄短花针茅种群密度、生物量呈负相关,各100μm植物沉积土壤团聚体含量与各年龄短花针茅种群密度、生物量呈正相关。研究认为,放牧降低了各年龄短花针茅种群密度和生物量,削弱了荒漠草地抵抗风蚀和沉降风沙的能力,降低了短花针茅改善基部土壤结构的生态功能,这可能是放牧草地退化过程的重要机制之一。
[Abstract]:Based on the experiment of grazing control in the desert steppe of Sunita Youqi of Inner Mongolia Agricultural University, this paper analyzes the structure of various groups and the characteristics of soil aggregates in the desert steppe.The potential relationship between Stipa breviflora (Stipa breviflora) and sedimentary soil under grazing control was revealed.The results showed that the density of young and adult plants was significantly higher than that of seedlings, the density of young and adult plants was significantly higher than that of seedlings, and the population density and biomass of Stipa breviflora at different ages were the highest under heavy grazing, followed by moderate grazing.The distribution of soil aggregates in Stipa breviflora desert steppe was affected by the particle size of aggregates and their interaction with grazing intensity (P0.05), and the highest concentration of plant sediment aggregates was 50 渭 m and 50 ~ 100 渭 m in the same grazing treatment.The content of aggregates was the lowest at 500 渭 m.However, there was a positive correlation between 50 渭 m soil aggregate content and 50 渭 m plant sedimentary soil aggregate content, while the 50 渭 m plant sedimentary soil aggregate content was positively correlated with the population density of Stipa breviflora.Biomass was negatively correlated, and the aggregate content of 100 渭 m plant sediment soil was positively correlated with the population density and biomass of Stipa breviflora.The results showed that grazing decreased the population density and biomass of Stipa breviflora at different ages, weakened the ability of desert grassland to resist wind erosion and sedimentation, and reduced the ecological function of Stipa breviflora to improve the soil structure at base.This may be one of the important mechanisms in the process of grassland degradation.
【作者单位】：内蒙古农业大学草原与资源环境学院;内蒙古农业大学理学院;
【基金】：国家自然科学基金项目(31460126) 国家重点基础研究发展计划项目(2014CB138805)
【分类号】：S812

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