高原鼢鼠对高寒草甸群落特征及演替的影响

EFFECT OF PLATEAU ZOKOR ON CHARACTERS AND SUCCESSION OF PLANT COMMUNITIES IN ALPINE MEADOW

研究结果表明, 高原鼢鼠种群密度与植物地上生物量呈极显著的负相关关系, 与双子叶植物在地上生物量中所占百分比的对数值呈极显著的正相关关系。草地次生植被面积随高原鼢鼠种群密度增加而显著增加, 土丘覆盖植物的恢复速率则随高原鼢鼠种群密度增加而显著地降低。植物群落组成的种数与种群密度呈显著的负相关关系。单子叶植物重要值随高原鼢鼠种群密度的增加而显著下降; 双子叶直根类植物与高原鼢鼠种群密度不存在显著的相关性; 双子叶植株内含次生化合物的物种重要值则与种群密度呈极显著的正相关关系。捕杀高原鼢鼠后, 禾草类、莎草类重要值上升, 植物地上生物量增加不显著( P> 0-05) , 但禾草类增加极显著(P< 0-01) 。

Effect of the population densities of plateau zokor ( Myospalax baileyi ) in six density grades selected in alpine meadow of Haibei,Qinghai Province on biomass,structure and succession of plant communities was examined quantitatively with data collected in May and August of 1995 and 1996.Species composition,biomass,recovering rate of plants after be covered by mounds among six grades showed strong changes. The species numbers,total biomass of aboveground and monocotyledon biomass showed significantly negative correlation with population density,respectively.However,there was significantly positive correlation between the population density of plateau zokor and the log value of bicotyledons percentage of total biomass.As the population density of plateau zokor increased,the importance value of monocotyledons decreased significantly.However,some bicotyledons which contain second chemical compounds increased rapidly,the importance value of some plants which have strong roots became the biggest in plant community while zokor density was in the middle grade.The important value and biomass of grasses increased significantly,but the biomass of total plants didn't increase after some of zokor population were removed.