放牧对小叶锦鸡儿种群数量特征的影响

摘要

To understand the effect of grazing on the quantitative characteristics of Caragana microphylla pop-ulation,we investigated the shrub cover,density,height,and total biomass of C.microphylla under non-graz-ing,light-grazing,moderate-grazing,and heavy-grazing treatments.The results showed that with increase in grazing intensity,the density of the C.microphylla shrub increased initially,and then decreased;however, there was no significant difference among the different treatments (P=0.1 1),suggesting,to some extent,that moderate grazing benefitted the reproduction of C.microphylla.Contrastingly,grazing significantly reduced the shrub cover,height,and total biomass of C.microphylla (P<0.05),suggesting that grazing had an obvi-ous negative effect on the shrub.Based on the quantitative characteristics of C.microphylla population under different grazing treatments,we suggested that moderate grazing intensity should be moderate-intensity grazing in desert steppes%本研究通过测定禁牧(CK)、轻度放牧(LG)、中度放牧(MG)和重度放牧(HG)下小叶锦鸡儿(Caragana micro-phylla)种群总盖度、密度、高度和总生物量,旨在掌握放牧对小叶锦鸡儿种群数量特征的影响.结果表明:随着放牧强度的增加,小叶锦鸡儿灌丛密度呈现先增加后减少的趋势,但各处理间无显著差异(P=0.11).这说明中度放牧在一定程度上有利于小叶锦鸡儿的繁殖.灌丛盖度、高度和总生物量随着放牧强度的增加而显著降低(P<0.05),这说明放牧对灌木种群有明显的负作用.综合考虑小叶锦鸡儿种群的数量特征和生产力,在荒漠草原上适宜的载畜率应为中度放牧.