作 者 ：王永健,钟章成*,陶建平
期 刊 ：生态学报 2008年 28卷 7期 页码：3082~3091
关键词：蝴蝶花；克隆植物；格局分析；物种多样性；生态位竞争；
Keywords:Iris japonica Thumb., clonal plant, pattern analysis, species diversity, niche competition,
摘 要 ：运用空间格局、生态位及多样性分析，探讨了重庆缙云山自然保护区林缘旷地(OAFE)、竹林(BF)及常绿阔叶林(EBF)3类生境蝴蝶花(Iris japonica Thumb.)自然种群分株格局特征及对草本多样性的影响机制。结果表明：方差均值比(V/m)和Moristia指数(Iδ)的格局判别分析表明，3类生境中蝴蝶花分株种群从0.5 m×0.5 m至2 m×2 m尺度均为聚集分布；从林缘旷地—竹林—常绿阔叶林，种群分株密度逐渐降低，总体格局规模与格局强度(PI)在各尺度均呈下降趋势。林缘旷地与竹林生境中，蝴蝶花的分布，降低了原优势种的优势度，并显著降低草本层物种多样性(p<0.05)，但在常绿阔叶林生境中对原优势种的优势度及草本物种多样性的影响很小。不同生境中蝴蝶花种群格局对草本多样性的影响机制各不相同：林缘旷地生境，通过强的更新生态位(地上空间与根生态位)与营养生态位(获取水分与养分资源)竞争，降低草本物种丰富度尤其是偶见种丰富度；竹林生境，通过更新生态位(根生态位)与营养生态位(获取光与养分资源)竞争，降低了草本偶见种丰富度；常绿阔叶林生境，物种间生态位重叠较低，表现一定的资源竞争，但对草本多样性影响很小。林冠决定蝴蝶花分株种群格局强度、克隆生长的强弱及林下土壤状况，从而影响蝴蝶花与草本层其它物种之间生态位竞争的强弱是决定蝴蝶花种群对草本层物种多样性影响机制的重要因素。
Abstract:Distribution patterns of ramet population of Iris japonica Thumb. and their effect on species diversity in the herb layer in three micro-habitats (open area of forest edge(OAFE), bamboo forest(BF) and evergreen broadleaved forest(EBF)) on Jinyun Mountain were studied using spatial pattern, niche and diversity analysis in a combination of population and community methods. The results were as follows: judged by V/m and Morisita index(Iδ), ramet population of I. japonica in three micro-habitats all clumped from scale 0.5 m×0.5 m to 2 m×2 m; the pattern scale and pattern intensity both gradually decreased in all scales and density of ramet population of I. japonica decreased with the increase in canopy density and the decrease in RPFD and R/FR from OAFE to EBF. In OAFE and BF, widespread I. japonica had a significantly negative influence on the dominance of original dominant species and on species diversity of the herb layer (p<0.05); however, those influences in EBF were extremely weak. The mechanisms that effect of pattern characteristics of I. japonica ramet population on species diversity of herb layer in three micro-habitats were different. In OAFE, high density and pattern intensity of I. japonica resulting from the open canopy which decreased the species diversity of the herb layer, especially for the richness of rare species, by means of strong regeneration niche (above-ground spatial niche and below-ground root niche) and trophic niche (nutrient) competition; in BF, moderate density and pattern intensity of I. japonica resulting from the bamboo canopy that had negative effect on the occurrence of rare species and on the survival of other herb species by means of strong regeneration niche (below-ground root niche) and trophic niche (above-ground for light and below-ground for nutrient) competition; in EBF, low density and pattern intensity resulting from the closed canopy which had little effect on the survival of herb species, because the random distribution of I. japonica caused by the low light in EBF lead to weak niche competition, just to trophic niche competition for nutrient. The pattern intensity and clonal growth of ramet population of I. japonica and soil status mainly determined by the canopy that have a significant influence on the intensity of regeneration niche (above-ground spatial niche and below-ground root niche) and trophic niche (above-ground for light and below-ground for nutrient) competition between I. japonica and other herb species, which is the determinant to the mechanism that effect of ramet population of I. japonica on species diversity of the herb layer.
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