Abstract: Chorthippus sp. and Gynaephora sp. are two dominate pests in the eastern alpine meadow of Qinghai Tibetan Plateau. This study is aimed to reveal the relationship between the abundance of the locust and caterpillar,the grassland plant characteristics and topographic factors and to verify their microhabitats characteristics. The density of locust and caterpillar was investigated by non-replaced samples every five days from May to September during 2010 to 2014 in alpine meadow of Xiahe,Gannan,eastern Qinghai Tibetan Plateau. The abundance,coverage and aboveground biomass (dry weight) of vegetation factors and topographic factors were measured,and their correlationship was analyzed. The results showed that there are significant correlations between the abundance of these two species and vegetation,as well as topographic factors. Locusts preferred flat and sunny middle slope,while caterpillar preferred flat only. The vegetation coverage was an important factor predicting the presence of locust. Areas with high biomass in flat area were more likely to be occupied by both species. The population dynamics of locusts is significantly related with plant coverage and biomass. The abundance of three plant species Koeleria glauca,Melissilus ruthenicus,Achnatherum splendens significantly affected habitat selection by locusts. The alpine grassland topographic factors and plant characteristics influences the locust and caterpillar both habitat use and habitat preferences.

Key words: Alpine meadow, Locust, Caterpillar, Distribution, Vegetation characteristics

摘要： 为探明甘南州夏河县高寒草甸草原蝗虫（Chorthippus sp.）和草原毛虫（Gynaephora sp.）的分布与其地形和植被因子的关系，本研究于2010年至2014年连续5年，定点选择30个样区，每年从5月至9月在各样地进行无放回取样调查密度，测量了植被的多度、盖度和地上生物量，并分析它们之间的相关性。结果表明：蝗虫选择分布在平地和半阳坡、坡中位的坡地，而毛虫只选择平地；植被盖度和地上生物量是影响草地蝗虫和毛虫分布的关键因子，与其种群密度呈显著的负相关关系；地上生物量较高的平地是蝗虫和毛虫共同分布的主要区域；洽草（Koeleria glauca）、花苜蓿（Melissilus ruthenicus）和芨芨草（Achnatherum splendens）3种植物多度与蝗虫分布显著相关，与毛虫分布不相关。可见，高寒草甸草原蝗虫和草原毛虫的分布与地形和植被因子显著相关，其栖息地利用特征有显著的偏好性。

关键词: 高寒草甸, 蝗虫, 毛虫, 分布, 植被特征