放牧作用下高寒草甸群落物种分布与土壤因子的关系

发布时间：2018-03-17 20:34

  本文选题：高寒草甸　切入点：群落特征　出处：《应用生态学报》2017年12期 　论文类型：期刊论文

【摘要】：以青藏高原东北缘高寒草甸为对象,研究不同放牧强度下植物群落和土壤因子的变化,以及群落物种分布与土壤物理结构和化学养分因子的定量关系.结果表明:放牧导致优势种为垂穗披碱草和大针茅的原植物群落发生分异,高强度放牧样地优势种变为矮生嵩草和阴山扁蓿豆,低强度放牧样地变为垂穗披碱草和冷地早熟禾.随放牧强度增加,物种丰富度、重要值和生物量均显著降低.各放牧强度样地重要值的物种序列均可用对数模型进行拟合;随放牧强度增加,植物重要值累积到占整个群落重要值50%时,需要的物种数降低.土壤速效P、速效K、紧实度、含水量、稳定入渗速率和大团聚体指标随放牧强度显著变化,但变化规律不一致.CCA排序表明,土壤紧实度是放牧作用下影响群落物种分布格局的最关键因子.方差分解表明,土壤因子共解释群落物种分布变异的30.5%,其中土壤物理性状单独解释群落物种分布的22.8%,对群落物种分布的贡献率最高,主要影响放牧干扰下高寒草甸植物群落物种的分布格局.
[Abstract]:The changes of plant community and soil factors under different grazing intensities were studied in alpine meadow in the northeast margin of Qinghai-Tibet Plateau. And the quantitative relationship between species distribution and soil physical structure and chemical nutrient factors. The dominant species of high intensity grazing plots were Kobresia humilis and Alfalfa sinensis, while the low-intensity grazing plots became Elaeagnus hypestris and bluegrass in cold land. With the increase of grazing intensity, species richness was increased. The species sequence of the important values of grazing intensity samples can be fitted by logarithmic model. With the increase of grazing intensity, the plant importance values accumulate to 50% of the whole community important values. Soil available P, available K, compactness, water content, stable infiltration rate and large aggregate index changed significantly with grazing intensity, but the order of change was not consistent. Soil compactness is the most important factor affecting species distribution pattern under grazing. Soil factors accounted for 30.5% of the variation of community species distribution, among which soil physical characters accounted for 22.8% of community species distribution alone, and the contribution rate to community species distribution was the highest, which mainly affected the distribution pattern of alpine meadow plant community under grazing disturbance.
【作者单位】： 甘肃农业大学草业学院/草业生态系统教育部重点实验室/中-美草地畜牧业可持续发展研究中心;毕节市畜牧兽医科学研究所;兰州大学生命科学学院;
【基金】：国家重点研发项目(2016YFC0501902) 国家自然科学基金项目(31460635)资助~~
【分类号】：S812
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本文编号：1626368