植物群落多样性和生产力对不同载畜率的响应

Response of Plant Community Diversity and Productivity on Different Stocking Rates

为探讨荒漠草原植物群落多样性和生产力在不同载畜率下的变化,试验采用完全随机区组设计,设置了4个不同载畜率,即不放牧对照(CK)、低载畜率(LG)、中载畜率(MG)、高载畜率(HG)。试验结果表明:(1)群落的高度、盖度、密度、生产力都随着载畜率增加显著下降(P<0.05)。(2)低、中载畜率下的丰富度指数、多样性指数显著高于重度放牧(P<0.05),低载畜率下的生产力显著高于高载畜率(P<0.05)却与中载畜率的生产力没有显著差异。(3)对照、低载畜率均匀度指数显著低于中、高载畜率(P<0.05)。(4)香农维纳指数、丰富度指数与生产力存在着极显著的线性相关关系,回归方程分别为Y=9.6076+234.3713X (R2=0.2933,P<0.001),Y=50.67+225.994X (R2=0.2933,P<0.001),均匀度指数与地上生产力没有相关关系。

To exploring the changes of plant community diversity and productivity in different stocking rates in desert steppe,the experiment adopted complete randomized design;treatments were four different stocking rates:no grazing(Contrast),light stocking rate(LG),moderate stocking rate(MG)and heavy stocking rate(HG)respectively.The results showed that:(1)The height,coverage,density and productivity of plant community decreased significantly with increasing stocking rate.(2)The species richness and species diversity of light and moderate stocking rate were higher significantly than that of heavy stocking rate;the productivity of the light stocking rate was significantly higher than that of heavy stocking rate(P<0.05),but there was no significant difference from that of moderate stocking rate.(3)The pielou index of no gazing and light stocking rate were significantly lower than that of moderate and high stocking rate(P<0.05).(4)There was a highly significant linear correlation between productivity and the shannonwiener and richness index,and the regression equation was Y=9.6076+234.3713 X(R2=0.2933,P<0.001),Y=50.67+225.994 X(R2=0.2933,P<0.001),respectively,but there was no correlation between productivity and pielou index.