中新天津生态城夏季啮齿类的空间生态位

Spatial Niche of Rodents in Summer in Sino - Singapore Tianjin Eco - City

2008年夏季对中新天津生态城的啮齿动物进行调查,采用Shannon-Wiener生态位宽度指数和Pianka生态位重叠指数对啮齿动物空间生态位进行了研究。结果表明,在捕获的5种啮齿动物中,小家鼠和黑线姬鼠的空间生态位宽度指数最高,分别为0.97和0.78;褐家鼠(Bi=0.58)和黑线仓鼠(Bi=0.51)次之;大仓鼠(Bi=0.36)最低。除了黑线姬鼠与其他4种啮齿动物两两之间空间生态位重叠指数均较小(C_P<0.50)外,其他4种啮齿动物两两之间均较高(C_P>0.50)。黑线仓鼠与褐家鼠空间生态位几乎完全重叠(C_P=0.99),在10对啮齿动物中,共有7对之间的空间生态位重叠指数大于0.70。由此可见,生态城啮齿动物之间存在资源竞争,主要原因是生态城是典型的盐碱湿地,可利用资源不丰富,使得动物分布相对集中,增加种间竞争。

In summer 2008, we surveyed rodents at Sino - Singapore Tianjin Eco-City. We quantified the spatial niche of rodents by use of the Shannon - Wiener niche breadth index and the Pianka niche overlap index. We captured five species of rodents. The Shannon - Wiener niche breadth indices for Mus musculus, Apodemus agrarius, Rattus norvegicus, Cricetulus barabensis, and Cricetulus triton were 0. 97, 0. 78, 0. 58, 0. 51 and 0. 36, respectively. Overlap indices between Apodemus agrarius and the other four rodent species were low （ Cp 〈 0. 50） , while the overlap indice between the other four rodent spe-cies were all high （ Cp 〉 0. 50 ） . The Pianka niche overlap index between Cricetulus barabensis and Rattus norvegicusis was the highest （ 0. 99 ） , confirming that their spatial niche overlapped almost completely. The Pianka niche overlap indices for 7 of the 10 possible pairings of rodents were over 0.70. This outcome suggests that some rodent species competed for resources in the Eeo - City. The main reason is that the Eco - City is a typical saline - alkaline wetland with limited resources. As a result, niche overlap of some rodent species was relative high,indicating interspecific competition for resources.