不同放牧率对草甸植被特征的影响

通过对羊草+苔草草甸进行受控放牧实验,定量研究了草地植被结构对不同放牧率条件下的反应特征。结果表明:所有不同放牧小区的四种牧草牧前高度远远低于对照小区,而且留茬高度差异不大。各种牧草放牧后的高度受草地群落生物量和牧草本身适口性的影响,适口性越高,降低程度越大。在整个生长季内,羊草+苔草草甸群落地上部分生物量一直处于不断增加的状态,其中苔草和芦苇地上生物量于6月份达到峰值;羊草于7月份达到峰值;香茅在整个生长季内不断增加,于8月份达到最大值。各放牧小区群落生物量均明显低于对照小区。随着放牧率的提高,多样性指数先增高后降低,即适度放牧有利于多样性的维持。

The Effect of Different Stocking Rates on Vegetation Characteristics in Meadow

By the controlled grazing experiment on The meadow dominated by Leymus chinensis and Carex,the response of characteristics of grassland vegetation structure to different stocking rates with cows were quantitatively analyzed.The results showed that : all the pastures in different grazing communities were more lower than control,and the difference of the stubble heights was small.The height after grazing was influenced by the biomass of the grassland communities and the palatability of pastures.When the palatability was higher,the extent of descending would be higher.In all the growing season,the biomass of Leymus chinensis and Carex meadow was always increasing.Biomass of Carex and Phragmites communis would reach its peak in June,Leymus chinensis would reach its peak in July,Hierochloe glabra would reach its peak in August.The community biomasses in different grazed plots were apparently less than that of the control.The index of diversity increased at beginning and then decreased with the increase of stocking rate.That means,moderate stocking rate is benefit to maintenance of diversity.