退化高寒草甸植被与土壤特征

The vegetation and soil characteristics of degraded alpine meadow

对甘肃省天祝县4个退化梯度高寒草甸的植被特征和土壤养分特征进行了研究。结果表明,随着退化程度的加剧,草地地上生物量、植被高度、盖度、土壤有机碳、全氮、全磷和土壤含水量都显著降低(P<0.05),重度退化草地土壤容重显著升高(P<0.05)。草地植物群落发生明显退化演替,矮生嵩草(Kobresia humilis)、线叶嵩草(K.capillifolia)和垂穗披碱草(Elymus nutans)的优势种地位被珠芽蓼(Polygonum viviparum)所替代,物种数由未退化样地的19种减少到重度退化样地的7种,退化指示类毒杂草生物量比例逐渐增加,由9.77%上升到62.93%。草地的退化程度会影响草地的植被特征和土壤养分特征,应根据不同退化阶段采取不同的恢复治理策略。

The study on characteristics of vegetation and soil nutritional features of alpine meadow under different degradation gradients were conducted in Tianzhu,Gansu Province.Results showed that the aboveground biomass,vegetation height,coverage,the soil organic carbon,total nitrogen,total phosphorus and soil water contents significantly decreased（P〈0.05）along with the degrees of degradation.Soil bulk density in severe degradation significantly increased（P〈0.05）.Grassland community showed degraded succession significantly such as the dominant species of Kobresia humilis,K.capillifolia,and Elymus nutans were replaced by Polygonum viviparum.The species number decreased from 19 to 7and the degraded plants biomass fraction increased from 9.77%to 62.93%.The characteristics of vegetation and soil nutritional features could be affected by degradation degrees,so the relevant strategies for restoration should be provided based on degradation degrees.