LTREB: Dynamics of Stream Ecosystem Responses Across Gradients of Reforestation and Changing Climate in a Tropical Dry Forest

该项目的科学和教育工作重点是通过长期研究大规模气候现象和森林恢复对当地生态的影响，提高我们对热带河流及其流域的认识。该项目在哥斯达黎加西北部的瓜纳卡斯特保护区（ACG）建立了几条小到中等大小的溪流。ACG包括各种各样的栖息地，这些栖息地在生态上不同，但又相互联系，包括原始干林、云雾林和雨林。干林之所以重要和有趣，是因为它是一种全球受威胁的生物群落，与公众普遍认为的热带环境是湿润的形成鲜明对比。它还包括森林被砍伐的地区，这是目前热带地区最大的森林恢复项目。ACG流流到太平洋和加勒比地区，范围从多年生到间歇，从暖到冷，从大到小。这项研究将深入了解河流对热带干燥森林的恢复和成熟、降雨的短期和长期变化（例如干旱或气候变化）以及供人类使用的短期和长期取水（在整个热带地区已经是一个问题）的反应。在解决研究课题和假设时，长期视角是必不可少的，因为它强调了随时间的变化和有助于确定当前和未来热带环境的极端环境。这个为期五年的项目以斯特劳德水研究中心14年的ACG河流数据库为基础，将大力管理ACG LTREB数据，并通过互联网向公众提供数据摘要。这将加强Stroud研究人员所研究的温带和热带站点之间的联系（包括宾夕法尼亚州的LTREB站点），并允许世界各地的学生和公众观察和研究ACG季节性干燥森林的条件和活动。

The scientific and educational efforts in this project focus on advancing our understanding of tropical streams and their watersheds through the long-term study of the local ecological impacts of large-scale climatic phenomena and forest restoration. This project establishes several small to intermediate size streams of the Guanacaste Conservation Area (ACG) in northwestern Costa Rica. The ACG includes a wide variety of habitats that are ecologically distinct as well as interconnected, including virgin dry forest, cloud forest and rain forest. The dry forest is of importance and interest because it is a globally threatened biome that contrasts markedly from the general public perception that tropical environments are wet. It also includes deforested areas that now represent the largest forest restoration project in the tropics. ACG streams flow to both the Pacific and Caribbean and range from perennial to intermittent, warm to cool, and large to small. The research will provide insight into stream responses to the recovery and maturation of tropical dry forests, short- and long-term variation in rainfall (e.g., droughts or climate change), and short- and long-term water withdrawals for human uses (already an issue throughout the tropics). A long-term perspective is essential in addressing the research topics and hypotheses because it highlights changes over time and the environmental extremes that help define present and future tropical environments. This five-year project builds upon the Stroud Water Research Center 14-year database for ACG streams, and a significant effort will be made in management of ACG LTREB data and making data summaries available to the public via the Internet. This will strengthen the connection between the temperate and tropical sites studied by Stroud researchers (including a LTREB site in Pennsylvania), and allow students and the public around the world to observe and study conditions and activities in the seasonal dry forests of ACG.