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

在世界各地，人们对恢复森林越来越感兴趣，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。但指导森林恢复的长期研究很少，特别是在热带地区。这个项目建立在一个现有的长期实验的基础上，该实验比较了不同的恢复热带森林的方法。这项研究将衡量在许多地点经过近20年不同处理后森林的恢复情况。这项研究还将回答有关附近的森林斑块对恢复恢复的地点有多重要的问题。成果将为土地管理人员和政策制定者提供关键指导，指导他们如何以及在哪里投资有限的资源，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探究式学习计划。15多年前，在哥斯达黎加南部100平方公里的区域内建立了12个试验点。这些地点被森林覆盖率从低到高的一系列地区包围。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--在整个地块种树。新的研究活动将包括对恢复和参考林地中的所有树木新兵进行密集调查，以彻底量化稀有的、后来继任的新兵。将制作一份详细的森林复盖率地图和地点周围个别重点树种的地图，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的传播，并进行种子额外的实验。总体而言，该项目将使用实地数据和遥感技术来解决热带群落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确定次生森林群落组成方面的相对重要性；初始立地条件的操纵对物种组成随时间的变化的影响程度；以及景观规模过程对长期森林恢复的重要性。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

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.