青藏高原不同退化程度小嵩草草甸群落结构特征与土壤理化特征分析

Analysis of community structure and soil physics and chemistry characteristics of different degraded Kobresia meadow in Qinghai-Tibetan Plateau

对青藏高原江河源区15个不同退化程度小嵩草草甸群落结构特征与土壤理化特征进行了研究，结果表明，随着小嵩草草甸退化程度的加大，小嵩草的重要值、优良牧草的数量趋于下降，毒草的数量趋于上升，而丰富度和杂类草数量的变化不明显；草地土壤含水量，〉2mm粒重，速效磷、速效钾、全氮、有机质含量在0～20cm土层波动幅度大，在20-40cm土层内波动幅度不明显，在40～60cm和（60-80）cm土层趋于稳定。

The community structure and soil land in Qinghai-Tibetan Plateau were analyzed. phy The sics and chemistry properties of different degradation grassmaea and the biomass of fine grass tended to decrease and the biomass of poison grass tended to increase as the increasing of intensive degradation grassland, but the dominance degree and the quantity of weeds were not obviously changed. Water content in soil,the grainy numbers （〉2 mm）, Quick release P, Quick release K, total nitrogen and the organic content were obviously changed in topsoil 0-20 cm, and little changed in 20-40 cm and 40-60 cm,while in 60-80 cm tending to stable.