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采用比较样地法研究了不同放牧强度对羊草草甸草原群落多样性和生产力的影响。结果表明:α多样性指数随放牧强度的增加表现为先增加后降低的趋势,其值在轻度放牧区最大,支持了“中度干扰理论”;β多样性指数随放牧强度的增加而变大;不同放牧强度的草地植物种类相似性变差、草地地上净初级生产力与Alatalo均匀度指数具有显著的线性相关性(P<0.05);放牧和气候对草地地上净初级生产力均有较大的影响,但二者的互作效应不显著(P>0.05);不放牧不能持续维持草地的健康状况,但健康的草地状况可以有效地缓冲放牧和气候干扰,并能够维持较高的草地生产力和生物多样性。
The effects of different grazing intensities on the diversity and productivity of the Leymus chinensis steppe community were studied by comparative sample method. The results showed that: α diversity index increased first and then decreased with the increase of grazing intensity, and its value was the largest in mild grazing area, supporting “moderate interference theory”; β diversity index increased with grazing intensity (P <0.05). On the other hand, grazing and climate had more significant effects on the net primary productivity of grassland than on grassland, and the grassland net primary productivity had a significant linear correlation with the Alatalo evenness index (P> 0.05). No grazing could not maintain the grassland health status continuously, but the healthy grassland condition could effectively buffer the grazing and climate disturbance and maintain the high grassland Productivity and biodiversity.