海南岛吊罗山热带山地雨林两个演替阶段的种间联结性

Species association in tropical montane rain forest at two successional stages in Diaoluo Mountain of Hainan Island

种间联结一直是群落演替理论研究的焦点之一,关于物种间相互作用与群落演替之间的动态关系仍然存在争议。本文中,作者通过出现—不出现数据的方差比例、基于2×2列联表的种间联结分析和x2检验,对海南岛吊罗山热带山地雨林演替前期和演替后期群落的种间联结性进行了研究,以揭示种间联结与群落演替的相互作用。结果表明:(1)在演替前期,群落内所有树种间总体呈正联结,但不显著(x20.95,50=34.764<W<x20.95,50=67.505);发展至演替后期达到显著正联结。群落内所有物种间正、负联结种对数占总种对数的比例随演替进程呈现下降趋势,而无联结种对数的比例则大幅上升;优势种和伴生种间呈现相同的趋势。这表明群落演替正朝着有利于物种稳定共存的方向发展。(2)演替前期建群种和后期侵入种间正联结与无联结种对数的比例(分别为37.8%与41.5%)远大于负联结的比例(20.7%),但正联结均不显著;前期定居树种和后期侵入种通过分割资源而共存,而且也趋于独立存在。(3)后期侵入种间不存在负联结,所有正联结(占总对数的33.3%)均达显著水平,显示它们对生境有相似的适应和相互重叠的生态位。

Species association is one of the basic concepts in community succession. There are different viewpoints on how species interaction changes with progression of succession. In order to assess these relationships, we examined species association in the tropical montane rain forest at early and late successional stages in Diaoluo Mountain of Hainan Island. Based on 2×2 contingency tables of species presence or absence data, statistical methods including analysis of species association and χ^2 test were applied. The results showed that： （1） the positive associations were present among overall woody species of the communities during the two successional stages, and were significant at the late stage. The number of species-pairs with positive and negative association all decreased through the process of succession, while the number with null associations increased drastically. The same trend existed among the dominant species and companion species. The results indicated that the communities were developing towards a stabilized stage in which the woody species coexisted in harmony. （2） As to the early-established species and later invading species, all positive associations among them were not significant. Compared with the positive and null associations, fewer negative associations were found. This implied that these species were inclined to coexist independently through resource partitioning. （3） Among the later invading species, positive associations were significant, and no negative associations were found, which suggested that these species had similar adaptative ability in the habitat and occupied overlapping niches in the community.