唐家河自然保护区小哺乳动物空间生态位初步研究

1989年4～11月，采用去除取样法，对四川省唐家河自然保护区内小哺乳动物的空间生态位宽度和重叠度进行了研究。共安置ll000铗日，捕获小哺乳动物14种846只。根据香农一威纳多样性指数公式以及Cowell和Futuyma公式分别计算了各小哺乳动物种群的空间生态位宽度和空间生态位重叠指数。在14种小哺乳动物中，社鼠的空间生态位宽度指数最大（1．00），大足鼠、川I西长尾朐、川朐和灰麝朐的最小，均为0。14种小哺乳动物空间生态位重叠指数最大为1，最小为0，其中大足鼠与川西长尾朐及灰麝朐、针毛鼠与川朐的空间生态位彼此完全重叠；藏鼠兔与针毛鼠、大足鼠、洮洲绒鼠、川西长尾朐、川朐以及灰麝朐的空间生态位完全分离。空间生态位完全重叠的种类，是通过选择不同的食物以及不同的微生境来避免过度竞争。回归分析显示，小哺乳动物种群的空间生态位宽度指数与它们利用空间资源的平均值呈显著的正相关（r=0．8285，P〈0．05）。空间生态位宽度指数的季节变化表明，社鼠种群分布没有明显的季节差异，中华姬鼠和安氏白腹鼠每年可能有一个数量高峰期，高山姬鼠一年则可能有两个数量高峰。

Preliminary Study on Spatial Niches of Small Mammals in Tangjiahe Nature Reserve

We collected data on small mammal communities in Tangjiahe Nature Reserve, Sichuan, during April-November, 1989. Indices of niche breadth and niche overlap were calculated using both Shannon-Weiner and Cowell and Futuyma Niche Overlap Index formulae. Niche breadth indices of 14 species varied from 0 to 1. Niviventer niviventer had the highest index of the niche breadth (1.00)while Rattus nitidus, Soriculus hypsibius, Blarinella quadrticauda and Crocidura attenuata had the lowest index of the niche breadth (0.00). Niche overlap indices also varied from 0-1. The spatial niche of R. nitidus completely overlapped that of S.hypsibius and C. attenuata. The spatial niche of Niviventer fulvescens completely overlapped that of Larinella quadrticauda. Ochotona thibetana was completely separated from Niviventer fulvescens, Rattus nitidus, Eothenomys eva, Soriculus hypsibius, Blarinella quadrticauda, and Crocidura attenuata. Small mammals had two different ways to avoid over-competition: food separation and microhabitat specialization. Regression analysis showed that niche breadth index increased significantly with the average amount of space resource utilization (r=(0.828 5), P<0.05). The analysis of seasonal variation of the niche breadth index indicated that there was no significant difference in distribution of N. niviventer in different seasons. During the research period, the pattern of population variation of Apodemus draco and N. Andersoni showed one peak and two peaks for A.chevrieri annually.