吉林蛟河近熟林树种多样性格局尺度依赖性分析

生境过滤和扩散限制是影响群落多样性格局组建的主要生态学过程,研究了物种多样性格局组建过程中不同生态学过程起作用的空间尺度。利用单物种-面积模型检验了其中40 种木本植物对邻域物种丰富度的影响,并且利用同质性泊松、异质性泊松、同质性托马斯和异质性托马斯过程分析了单物种-面积关系偏离中性状况的显著性。研究结果表明,毛榛、鼠李、早花忍冬、茶条槭和花曲柳在0 ~50 m 空间尺度上为生物多样性促进种;糠椴和千金榆分别在0 ~25 m 和0 ~35 m 尺度上为生物多样性抑制种;其他绝大多数树种表现为中性种。扩散限制对群落多样性格局组建影响较大,而生境过滤作用影响相对较小。异质性托马斯过程同时剔除了生境过滤和扩散限制影响,分析结果显示0 ~20 m 尺度上促进种在群落中占据支配地位;在20 m 尺度上中性种比例随着空间尺度增加而增大,在群落多样性构建过程中占据主导地位;群落中抑制种比例较低,并且随着空间尺度变化幅度不大。因此,生态位分化和中性作用共同决定了群落多样性结构的构建过程,二者的相对重要性与空间尺度密切相关。 

Scale dependence of species diversity pattern in a near-mature forest in Jiaohe of Jilin Province

Both habitat filtering and dispersal limitation are the key ecological processes affecting the structuringof community diversity pattern. The spatial scales at which different ecological processes work weredetermined in the structuring of species diversity pattern. The effect of 40 woody species on the localspecies richness was examined by individual species-area relationship model. The significance ofdeviation of individual species-area relationship from neutral condition was analyzed by homogeneousPoisson process, heterogeneous Poisson process, homogeneous Thomas process and heterogeneous Thomasprocess. The results revealed that Corylus mandshurica, Rhamnus davurica, Lonicera praeflorens, Acerginnala and Fraxinus rhynchophylla were diversity accumulators at 0-50 m spatial scales. Tiliamandshurica at 0-25 m scale and Carpinus cordata at 0-35 m scale were diversity repellers, while most ofother species were neutrals. The dispersal limitation greatly affected the structuring of community diversitypattern; however, the effect of habitat filtering was relative small. Heterogeneous Thomas model couldsimultaneously exclude the effects of habitat filtering and dispersal limitation. The results indicated thatdiversity accumulators were dominant at 0-20 m spatial scales in forest community. The proportion ofdiversity neutrals at scale 20 m increased with the increasing spatial scales, and the diversity neutralsdominated the structuring of the community diversity. Diversity repellers kept in a very low proportion atall scales. Thus, the niche differentiation and neutral processes jointly determined the structuringprocesses of community diversity, and the relative importance of both was closely correlated with thespatial scales.