Collaborative Research/LTREB Successional pathways and rates of change in tropical forests of Brazil, Costa Rica, and Mexico

本项目关注农业废弃后次生林的再生过程。目前在亚马逊中部（巴西马瑙斯）、哥斯达黎加东北部和墨西哥恰帕斯进行的独立研究表明，观察到的森林内植被变化往往与基于对遗弃以来不同年龄森林的单次研究的预测相偏离。该项目结合了拉丁美洲潮湿热带森林的四个现有项目。将在长期研究地块上进行协调的年度植被普查，以验证一系列因变量（包括茎密度、大小分布、基底面积、生物量、物种丰富度、物种组成和生命形式组成）的特定时序预测。观测到的因变量变化率将与基于最佳拟合统计模型的每个区域内时间序列研究的预测变化率进行比较。通过了解林分动态如何符合或偏离这些区域内的总体时序模式，研究人员将确定影响演替途径的关键生态因子、过程和机制。收集的长期数据将为指导新热带地区的森林恢复、碳封存和生物多样性保护提供重要信息。最终，这项研究的结果将有助于在当今复杂的热带景观中开发更具预测性和更广泛应用的植被演替动态模型。

This project focuses on the process of secondary forest regeneration following agricultural abandonment. Current independent studies conducted in Central Amazonia (Manaus, Brazil), northeastern Costa Rica, and Chiapas, Mexico reveal that observed vegetation changes within forests often deviate from predictions based on single-time studies of forests of different age since abandonment. This project unites four existing projects in wet tropical forests of Latin America. Coordinated annual vegetation censuses in long-term study plots will be conducted to test specific chronosequence predictions for a range of dependent variables including stem density, size distributions, basal area, biomass, species richness, species composition, and life-form composition. Observed rates of change in dependent variables will be compared with predicted rates from chronosequence studies within each region, based on the best-fit statistical models. By understanding how stand-level dynamics conform to or deviate from overall chronosequence patterns within each of these regions, the researchers will identify key ecological factors, processes, and mechanisms that influence successional pathways. The long-term data gathered will provide essential information to guide forest restoration, carbon sequestration, and biodiversity conservation in the Neotropics. Ultimately, results from the study will enable development of more predictive and more widely applied models of successional vegetation dynamics in today's complex tropical landscapes.