热带森林演替过程中土壤养分异质性对幼苗多样性和更新的驱动作用

热带森林是处于循环动态演替过程中的生态系统。其幼苗群落建立、更新和发展是驱动森林演替和多样性维持的重要机制和必然过程。虽然已知热带雨林中的小尺度土壤养分异质性是影响幼苗群落结构的重要因素，但演替进程中，因地上植物变化导致土壤养分异质性与植物群落耦合关系的时空格局差异，及其对幼苗生长和群落发展的驱动作用仍缺乏深入的量化分析。本研究以植物-土壤-幼苗为研究体系，通过对不同演替阶段热带森林土壤养分异质性测定，并结合原位及移栽幼苗的时空动态监测，在群落水平上阐明热带森林土壤养分异质性斑块的大小和空间自相关性，量化不同演替阶段植物生物量空间格局对土壤养分异质性形成的贡献，并深入解析小尺度土壤养分异质性对幼苗群落多样性、空间分布和不同生态策略树种幼苗更新的影响及其关键途径。结果对构建土壤养分异质性空间结构与植物多样性的相互作用关系，丰富热带森林植物与土壤互反馈作机制的内涵提供新的理论、技术和数据支持。

Tropical forest is an ecosystem in the process of cyclic dynamic succession. The establishment, regeneration and development of its seedling community are important mechanisms and inevitable processes that drive forest succession and maintain diversity. Although it is known that fine-scale soil nutrient heterogeneity in tropical rain forest is an important factor affecting the structure of seedling community, there is still a lack of in-depth quantitative analysis on the spatial and temporal pattern differences in the interaction relationship between soil nutrient heterogeneity and plant community caused by above-ground plant changes in succession process, and its driving effect on seedling growth and community development. In this study, plant-soil-seedlings were taken as the research object, through the determination of soil nutrient heterogeneity in tropical forests at different succession stages, combined with the spatio-temporal dynamic monitoring of in situ and transplanted seedlings, we aim to clarify the soil nutrient patch size and spatial autocorrelation in tropical forests, quantify the contribution of plant biomass spatial patterns to the formation of soil nutrient heterogeneity at different succession stages, and in-depth analysis of fine-scale soil nutrient heterogeneity on seedling community diversity and spatial distribution, and the key ways of regeneration of tree species with different ecological strategies. The results provide new theories, techniques and data support for constructing the interaction relationship between the spatial structure of soil nutrient heterogeneity and plant diversity, and enriching the connotation of plants-soil feedback mechanism in tropical forest.