基于点格局过程的扩散限制和生态位分化作用的分离与量化

This study starts from spatial distribution of tree species and their generating mechanisms to discover the key spatial signatures for decoding mechanisms of species coexistence and biodiversity maintaining. This study was carried out in a 20ha subtropical forest plot in Dinghushan Mountain, Guangdong province. Based on field survey and sampling analyses, data of individual, terrain, soil properties, seeds and seedling will be used to set up a longtime and integrated s subtropical forest survey system and sharing network data flat. First of all, based on the longtime habitat and seed rain data, this study will deeply analyze reasons that can generate spatial aggregation pattern in subtropical forest. We will continue to find laws that control spatial distribution patterns to change with scales and time, also to discover biologic and abiotic factors that work on distribution patterns. Secondly, this study will model point patterns of tree distribution, for the purpose of identifying processes that may generate spatial patterns of tree communities. We used four primary point pattern processes to simulate spatial processes of habitat association and seed dispersal, allowing us to evaluate the potential contribution of habitat heterogeneity and dispersal limitation to the formation of spatial patterns of tree species. Moreover, we also use species attributes, including species abundance and dispersal mode to predict the best ?t models of point pattern processes, for the purpose of understanding the impact of species attributes on distribution pattern generation. Understanding processes underlying spatial distribution of tree species is fundamental to studying species coexistence and diversity.The separation of habitat heterogeneity and dispersal limitation may potentially contribute to reconciling the niche versus neutral debate, thus increasing our ability to understand the mechanisms of species coexistence. Finally, we can explain what are the main mechanisms of species coexistences and biodiversity maintain in subtropical forestry. And then, we can put forward effective and integrated strategies for biodiversity protection.

从研究物种分布格局和产生机制入手，首先结合生境和种子扩散数据深入挖掘聚集格局形成的原因，探讨物种分布格局的时空变化规律和影响分布的生物和非生物因素；其次选择代表空间点格局产生过程的随机、生境相关作用、扩散限制作用和扩散限制与生境相关联合作用过程的模型；对模型性能进行评价，分离和量化生态位分化和扩散限制作用对格局形成的贡献；并把物种特性与模型结合，探讨物种特性对格局产生机制作用的影响。理解物种空间分布格局的形成过程是物种共存和生物多样性研究的基础和突破点。分离这两种机制的作用有利于消除生境分化和中性理论之间的争论，进而加深我们对物种共存机制的理解。研究以鼎湖山20ha样地为研究平台，通过野外调查和采样分析，获取植物物种、地形、土壤、种子及幼苗数据，建立起长期完善的南亚热带森林监测体系和网络数据共享平台。最终明确影响整个南亚热带森林物种共存和多样性维持机制，提出生物多样性有效的综合性保护方案。

研究物种的分布格局和形成原因，对揭示森林群落物种共存和多样性维持机制具有关键作用。国内外对此类问题的研究也很重视。借助本项目的资助，我们从不同层面进行探索南亚热带森林群落物种的时空分布，对群落维持机制进行了深入研究。首先，通过近三年对鼎湖山南亚热带森林群落的持续监测，进一步完善鼎湖山森林生物多样性监测网络平台，完善了南亚热带森林生物多样性长期监测的指标体系和监测规范。其次，通过探索亲缘种在群落中的分布和成因，群落中建群种死亡动态分析，群落个体最佳多度分布模型拟合，群落中个体更新策略探索等方面的研究工作，从不同多样性水平和尺度上比较揭示南亚热带森林物种分布格局成因，对群落构建中多样性维持机制进行了探讨。研究结果提示在南亚热带异质性森林群落中，生态位分化和扩散限制联合作用能很好的解释多样性分布和种面积关系，生态位分化作用在物种格局形成的各个生态过程中都起到主要作用。最后，针对野外调查速度和精准度难以保证的问题，我们还开展了树高和定位一体化便携仪器的研制，获取了针对山地树高测量的新算法，并首次探索把物种精准定位和树高测定集成用以研制适于野外监测的便携仪器。到目前为止，研究成果共发表中英文论文7篇，其中三篇SCI论文，出版专著一部，申报专利2项,已授权1项。