甘肃马鹿夏季牧场草地植物群落特征

Plant community characteristics of grazing grassland in a deer farm in summer

在祁连山北坡中段甘肃马鹿(Cervus elaphus kansuensis)夏季牧场,分析在不同地形和不同放牧强度共同作用下高寒草甸植物和高寒灌丛植物群落物种多样性、功能群多样性、高度、冠幅及其重要值。结果表明,1)谷地、阳坡、阴坡3种坡向,随着放牧强度的增大,总物种数在中度放牧时最高;阴坡,轻度放牧和中度牧牧群落功能多样性显著高于重度放牧(P<0.05)。2)不同地形,α多样性指数几乎在中度放牧下最高,重度放牧下最低。在不同放牧强度下,谷地的物种丰富度最大,而Shannon-Wiener多样性指数最小。3)阴坡,轻度放牧豆科株高、冠幅及重要值最大;谷地和阳坡莎草科重要值随着放牧强度的增加而增多,阴坡与之相反;禾本科植物重要值在中度放牧下最大;可食阔叶草重要值随着放牧强度的增加而增多,且在谷地最大;不喜食植物重要值随着放牧强度的增加而上升,且在阳坡最大。

In the summer pasture in the middle section of the northern slope of Qilian Mountain,the species diversity,functional group diversity,height,crown width and important values of alpine meadow and alpine shrub community under different topographical and different grazing intensities were analyzed.We found that:1)with the increase in grazing intensity,the total species number was the highest under grazing,which is consistent with the“moderate disturbance hypothesis”.Under‘shady slope’conditions,the community functional diversity of light and moderate grazing was significantly higher than that of heavy grazing(P<0.05).2)The alpha diversity index was almost greatest in moderate grazing and the lowest in heavy grazing conditions of different topography.Under different grazing intensities,the valley had the highest species richness but the lowest Shannon-Wiener diversity index.3)The plant height,crown width and important value of legume in light grazing on shady slope were the largest,the important values of Cyperaceae in valley and sunny slope increased with the increase of grazing intensity,the contrary in shady slope;the important value of Gramineae was the highest in middle grazing.The important value of Edible broadleaf increased with the increase of grazing intensity,and reached the maximum in the valley;the important value of Undesirable plant increased with the increase of grazing intensity,and there was the maximum value on the sunny slope.