Collaborative Research: Spatial and temporal patterns of secondary tropical forest succession

在世界各地，人们对恢复森林的兴趣越来越大，因为森林可以改善水质，储存碳，保护生物多样性，并确保人类福祉。但是很少有长期的研究来指导森林恢复，特别是在热带地区。该项目建立在现有的长期实验基础上，该实验比较了恢复热带森林的不同方法。这项研究将衡量在许多地点经过近20年的不同处理后，森林恢复的情况。该研究还将回答有关附近森林斑块对恢复恢复遗址的重要性的问题。研究结果将为土地管理者和决策者提供重要指导，指导他们如何以及在何处投资有限的资源，以改善森林恢复工作。该项目将为大学生开发有关森林管理和恢复的在线课程，并继续为高中生提供基于探究的学习计划。15年多前，在哥斯达黎加南部100平方公里的地区建立了12个实验点。这些地点被一系列从低到高的森林覆盖所包围。每个地点有三个试验处理：（1）低强度-不植树和自然恢复，（2）中等强度-种植三种大小的树岛，（3）高强度-种植整个地块的树木。新的研究活动将包括首次对恢复和参考森林地块中的所有树木新兵进行深入调查，以彻底量化罕见的后期演替新兵。将绘制一张详细的森林覆盖图和这些地点周围的个别重点树种，以评估接近种子来源的重要性。为了更好地了解限制森林恢复的因素，调查人员将测量种子传播并进行种子添加实验。总的来说，该项目将利用实地数据和遥感技术来解决热带社区生态学中关于后期演替树木补充动态的一系列关键辩论。这些争论包括种子传播、幼苗建立和树木生长在决定次生林群落组成中的相对重要性;初始立地条件的操作对物种组成随时间变化的影响程度;以及小规模进程对长期该奖项反映了NSF的法定使命，并通过使用基金会的智力价值进行评估，被认为值得支持和更广泛的影响审查标准。

Around the world, there is growing interest in restoring forests, which improve water quality, store carbon, conserve biodiversity, and ensure human wellbeing. But there are few long-term studies to guide forest restoration, especially in the tropics. This project builds on an existing long-term, experiment that compares different ways of restoring tropical forest. The research will measure how well forests are recovering after nearly two decades of different treatments at many sites. The study will also answer questions about how important nearby forest patches are to the recovery of the restored sites. Results will provide critical guidance to land managers and policymakers on how and where to invest limited resources to improve forest restoration efforts. The project will develop online lessons about forest management and restoration for college-level students and continue an inquiry-based learning program for high school students.More than 15 years ago, 12 experimental sites were established over a 100 square-kilometer area in southern Costa Rica. Sites are surrounded by a range of low to high forest cover. Each site has three experimental treatments: (1) low intensity -- no tree planting and natural recovery, (2) medium intensity -- planting tree islands of three sizes, and (3) high intensity -- planting the entire plot with trees. New research activities will include conducting an intensive survey of all tree recruits in restoration and reference forest plots for the first time to thoroughly quantify rare, later-successional recruits. A detailed map of forest cover and individual focal tree species surrounding the sites will be created to assess the importance of proximity to seed sources. To better understand factors limiting forest recovery, investigators will measure seed dispersal and conduct seed-additional experiments. Overall, the project will use field data and remote sensing techniques to address a host of key debates in tropical community ecology about the dynamics of later-successional tree recruitment. These debates include the relative importance of seed dispersal, seedling establishment, and tree growth in determining secondary forest community composition; the degree to which manipulations of initial site conditions affect changes in species composition over time; and the importance of landscape-scale processes on long-term forest recovery.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.