关键词: 鼠兔, 丰富度, 食物谱, 食物资源谱, 生态龛, 选择性, 采食高度, 害鼠

Abstract: The food utilization of the plateau pika (Ochotona curzoniae Hodgson) was observed at Haibei Alpinal Meadow Ecosystem Researching Station(Lat. 37°9′-37°5′N, Long.l01°2′-101°3′E). Ten sampling plots of 25 x 25cm² were chosen at random to study the coverage, biomass and number of different plant species, from which the abundance of the species in the meadow were estimated, then the food resources were to be inferred accordingly (Tab.l). The grazing freqencies of the pika to various food were recorded to determine the degrees of utilization and the grazing heights of the pika were measured as well. Then the relative grazing heights were compared (Tab.2). The results of the study were as follows:1. The grazing frequencies of the pika disagree with the abundance of the food resources because the pika utilizes the food resources selectively. The pikas tend to like such food as Elymus nutans, Oxytropis, Poa, but dislike Kobresia. So they play an important role in stablizing the alpine meadow vegetational community.2. With the increase of the experimental density, the food utilization spectrum changed (Fig.l).(1) The food spectrum was generalized. ( 2) The grazing heights were lowered (Tab.2 and Fig.6),both leading to the generalization of the niche,and (3) Changes in the composition of the vegetational community (Fig.5).3. The pika of high density is surely harmful.They destroy the grassland by digging burrows. So the pika of high density should be controlled.

Key words: Pika, Ochotona curzoniae, Abundance, Food spectrum, Food resource spectrum, Niche, Selectivity, Grazing height, Rodent pest