【摘要】 β多样性反映了不同群落间的物种组成差异,是联系局域与区域生物多样性、描述物种空间分布格局的重要指标。本研究以小兴安岭的天然林为研究对象,基于森林群落调查数据,探讨了森林β多样性格局、组分及其影响因素,旨在明确森林β多样性的分布格局及其驱动机制,为该地区的生物多样性保护提供科学依据。通过Podani方法将β多样性进行分解,探讨了物种替换与丰富度差异对β多样性的相对贡献;同时将β多样性划分为不同样方对多样性的贡献(LCBD)和不同物种对多样性的贡献(SCBD),进而识别具有生态特异性的关键区域和物种;最后通过回归分析和变差分解量化不同环境、空间因子以及人为干扰对群落组成差异的影响,揭示驱动森林群落构建和生物多样性格局的生态机制。结果表明:(1)物种替换是影响研究区群落β多样性的主要过程;(2)研究区SCBD的范围为0.002%–21.918%,其中白桦(Betula platyphylla)对β多样性的贡献最大,香杨(Populus koreana)的贡献最小;(3) LCBD的范围为0.537%–2.677%, LCBD较高的样方通常具有较高的物种丰富度,且整体呈现出东南高、西北低的分布格局;(4)气候因子是影响LCBD格局的主要环境因素,其与空间和地形因子以及人为干扰共同作用,通过调控降水和生境异质性,共同塑造了群落物种组成和多样性分布格局。研究结果揭示了小兴安岭森林β多样性的分布格局与影响机制,明确了对维持森林β多样性具有显著意义的区域和物种,可为该地区森林生态系统管理和生物多样性保护提供一定的科学依据。更多还原

【Abstract】 Aims: β diversity reflects the differences in species composition among communities, serving as a key indicator linking local and regional biodiversity while characterizing spatial distribution patterns of species. In this study, using data from a large forest observation network in the Xiaoxing’an Mountains, we disentangled the patterns, components, and influencing factors of forest β diversity, aiming to provide a scientific basis for biodiversity conservation in this region. Methods: Using the Podani partitioning method, we decomposed β diversity to assess the relative contributions of species replacement and richness difference. We further quantified the local contribution to β diversity(LCBD) and the species contribution to β diversity(SCBD) to identify ecologically unique sites and key species. In addition, regression and variance partitioning analyses were applied to evaluate the relative effects of environmental, spatial and human disturbance factors on community composition, thereby uncovering the ecological mechanisms underlying forest community assembly and biodiversity patterns. Results:(1) Species replacement was the dominant process driving community dissimilarity across the study area.(2) The SCBD values ranged from 0.002% to 21.918%, with Betula platyphylla contributing the most and Populus suaveolens the least. Species with higher SCBD values largely overlapped with the dominant tree species in the region.(3) LCBD values ranged from 0.537% to 2.677%. Plots with higher species richness exhibited higher LCBD values, with southeastern sites generally having greater LCBD values than those in the northwestern.(4) Climatic factors were identified as the primary drivers of LCBD variation. The interaction between climate, spatial, topographic, and human disturbance variables influenced water availability and habitat heterogeneity, thereby indirectly shaping species spatial distribution patterns. Conclusion: Our findings reveal the spatial patterns and ecological drivers of forest β diversity in the Xiaoxing’an Mountains, highlight key regions and species essential for maintaining β diversity, and provide scientific evidence for forest ecosystem management and biodiversity conservation in this region.更多还原