Abstract: The effects of plateau pika on grassland ecosystems have received much attention,while the effects of multi-year pika eradication on its population size dynamics and plant community structure are less investigated. In this study,we eradicated the plateau pika within nine consecutive years and three times per year in alpine meadows seriously impacted by plateau pika in Henan County,Qinghai Province,to study the effects of multi-year pika eradication on the plateau pika population size and plant community structure. The results showed that plateau pika population density decreased rapidly in the first four years,while did not change obviously in the last five years. Plant community cover,height and above-ground biomass increased significantly with eradication time,and were negatively correlated with the plateau pika population density,which indicated that high density pika population size was detrimental to the maintenance of plant cover and aboveground biomass. The influnce of climatic factors on the above-ground biomass of plants was stronger than pika population size,and its influence on pika population size was also stronger than the time of eradication. Therefore,for alpine meadows with severe rodent infestation,rodent eradication synergizing with climatic factors influenced the size of plateau pika population and the structure and function of plant communities.

Key words: Alpine meadow, Plateau pika, Grassland degradation, Rodent eradication, Rodent eradication time, Community structure

摘要： 高原鼠兔对草地生态系统的影响备受关注,而多年鼠类防控对高原鼠兔种群数量与植物群落结构影响的研究鲜见。本研究通过对青海省河南县鼠类种群密度较高的高寒草甸进行了连续九年、每年三次的鼠类防控和监测,研究多年鼠类防控对高原鼠兔种群数量及植物群落结构的影响。结果表明:前四年连续的鼠类防控显著地降低了高原鼠兔种群密度,而后五年高原鼠兔种群密度下降趋势并不明显;随着鼠类防控年份的增加,植物群落盖度,高度和地上生物量均显著增加,且它们与鼠兔种群密度呈显著的负相关关系,一定程度上说明高密度的鼠兔种群数量不利于植物盖度和地上生物量的维持;气候因子比鼠兔种群大小更能解释植物地上生物量的变化,其对鼠兔种群密度的影响也大于持续鼠类防控的影响。因此,对于鼠害严重的高寒草甸,鼠类防控协同气候因子共同影响着高原鼠兔种群大小和植物群落结构及功能。

关键词: 高寒草甸, 高原鼠兔, 草地退化, 鼠类防控, 灭鼠时间, 群落结构