Abstract: From May 1980 through October 1982, two isolated populations of the root vole. M icrotus oeconmus, were investigatod with Catch-Mark-Release (CMR) method at the Haibei Alpine Ecosystem Research Station,Academ ia Sinica,and the first objective of this research was to study population dynamics of this species.
The major features of the population fluctuations are as follows: 1)This species showed relatively less year-to-year density fluctuation, especially the size of spring population . The peak density fluctuated with a range not more than 50%. 2)Population fluctuation was of typical annual(seasonl)with the lowest density(about 10/ha.) in spring orearly summer, and peak density(about 65/ha.) in fall. Also in the present study, by analyzing other demographic traits( timing of breeding, survival, and age struture) and their relationships with population fluctuation, we suggest that climatic factors affect size level of the population, and behavioral regulation play a primary role in maintaining relatively stable popualton.

Key words: Root vole (Microtus oeconomous), population dynamics, surrval rate, age structure, population regulation

摘要： 1980-l982年在青海省海北高寒盘露梅(potentillafruticosa)灌丛地区，用标志重捕法(CMR)对自然栖息地中的根田鼠(Microtus oeconomus)进行了野外调查。本文主要分析了根田鼠种群量变动特点和繁殖，存活及年龄结构与种群动态的关系，并试图探讨根田鼠种群的稳定机制。

关键词: 根田鼠, 种群动态, 存活率, 年龄结构, 种群调节