Abstract: Eighty-six eld's deer(Cervus eldi hainanus)werc included in the fence which was established in the Datian National Nature Reserve in 1986 and made an insulated population．Population size increased to 158 within 3 reproductive periods while the vegetation condition in the fencc changed．Density,height，and frequency of plant species which arc preferred by deer decreased and species which are less or not preferred increased．Natality and yearly incrcase rate of the deer population decreased year by year as the population size increased．The effect of crowding and physiological stress and shortage of food resources were the main reasons for the decline 0f population natality and yearly increase rate．Suggestions were given to managers of the Nature Reserve for management of deer and habitat．

Key words: Hainan eld g deer, Population size, Vegetation condition, Fo d reaource

摘要： 1986年海南省大田国家级自然保护区在境内设立面积为95公顷的围栏，将86只海南坡鹿分隔成一个孤立的种群。经过3个繁殖年度，种群发展到158只。随着种群数量的增加，坡鹿采食植物的种类密度、高度和频率均明显减少，而坡鹿不食的植物种类则明显增加。种群出生率和年度增长率随种群数量增加而逐年降低，而种群死亡率却有增加趋势。种群密度过高产生的拥挤效应和食物资源不足是造成种群出生率和年度增长率下降的主要原因。本文还就保护区应采取的管理措施，提出了相应的建议。

关键词: 海南坡鹿, 种群数量, 植被状况, 食物资源