放牧对温性荒漠草原植物群落及草地土壤肥力的影响

Effect of Grazing on Plant Community and Soil Factors of Temperate Desert Steppe

对不同放牧强度下温性荒漠草原草地植物群落特征及土壤理化性质进行了测定,并对两者的关系进行了研究。结果表明:放牧强度不同,温性荒漠草原草地植物的优势种不同,优势植物的高度和频度也会发生相应变化;植被总盖度和总密度及地上生物量在重牧区极显著低于其他放牧区(P<0.01);土壤水分、全氮、有机质、速效磷及速效钾等主要土壤因子均为轻牧区极显著高于其他放牧区(P<0.01),而土壤容重则相反;植被总密度与土壤pH和土壤容重成负相关,与土壤含水量、土壤有机质和全氮成正相关;植物群落盖度除与土壤有机质显著相关外,与土壤含水量、容重、全氮和pH之间相关不显著或成负相关(P>0.05);群落地上生物量与土壤pH、容重和全氮成负相关,与含水量和有机质成正相关。

The plant community characteristics and physical and chemical factors of soil in temperate desert steppe under different grazing intensities were analyzed.Results showed that plant dominant species were different between different grazing intensities and the height and frequency of the dominant species changed accordingly too.The total cover and gross density of vegetation were lower in heavy grazing than in other grazing areas significantly（P0.01）.The contents of water,total nitrogen,organic matter,available phosphorus and potassium in soil were higher in light grazing area than in other areas significantly（P0.01）,but soil bulk density lower.Gross density had negative correlation with pH and bulk density of soil,but had positive correlation with the contents of water,organic matter and total nitrogen.Total plant coverage showed no or negative correlation with all soil factors except organic matter.Aboveground biomass had negative correlation with pH,soil bulk density and total nitrogen but had positive correlation with water and organic matter.