羊草个体性状对不同放牧模式响应的研究

Responses of Leymus chinensis Individual Traits to Different Grazing Patterns

为了解放牧系统中优势植物个体性状的响应机制和方式,可为草地持续利用及健康管理提供相应的科学依据。在河北沽源草地生态系统野外站以连续5年放牧的典型草原中优势植物羊草(Leymus chinensis)为研究对象,对不同放牧模式下羊草的株高、地上、地下生物量、根冠比等个体性状进行观测。结果表明:长期过度放牧导致羊草植株变矮,冠丛幅降低;放牧改变了羊草生物量分配,增加了地下生物量所占比例;羊草地上部对放牧干扰响应强烈,地下部对放牧响应较地上滞后,根系含水量有随放牧强度加大而增加的趋势。羊草个体性状对不同放牧模式有着不同的适应策略,对秋季重度放牧方式响应强烈。

To find out the effect of grazing on plant individual traits in typical steppe,a field experiment was conducted in the experimental station of grassland ecosystem in Zhangjiakou.The land grazed for five years consecutively was sampled.Plant height,aboveground biomass,belowground biomass,root water content and the ratio of root to shoot were measured for analyzing the responses of Leymus chinensis individual traits to different grazing patterns.The results showed that grazing induced the changes of individual traits in the typical grassland of Inner Mongolia.Plant height and crown plexus picture were reduced with long-term overgrazing.Grazing changed the biomass allocation and increased the proportion of underground biomass.Aboveground had more fierce and rapid response to different grazing patterns than belowground.Root water content increased with the increase of grazing intensity.Over grazing had bigger destructiveness to the grassland in fall than in summer.