RAPID: Growth, Mortality, and Competition of Tropical Tree and Liana Species During an Extended Drought

生态学的一个主要目标是理解为什么不同类型的植物和动物会出现在它们所处的地方。这个问题对热带森林特别重要，因为它们是世界上大多数物种的家园，对全球碳和养分循环至关重要;它们有助于控制整个地球的大气。从某种意义上说，热带植物是地球的“肺”。科学家们开始认为，干旱在决定热带森林“呼吸”的好坏方面至关重要。 然而，这方面的证据仍不清楚。 在这个项目中，研究人员将测试不同的热带植物物种如何应对巴拿马持续多年的干旱。来自美国的本科生和研究生将参加该项目，并接受如何进行科学研究的培训。在一个大规模的长期竞争实验的背景下，PI将研究多年干旱的作用，以测试两个预测：1）植物-植物竞争的强度随着干旱而增加，并随物种身份而变化。2)利用干旱的植物物种将共享一套植物水力功能特性。通过测试这些预测，PI可以提供不同物种如何应对干旱的功能机制解释，并确定植物-植物竞争是否加剧了干旱的影响。通过研究100多个植物物种的反应，并将这些反应与每个物种的一套功能特征相关联，该项目将确定可能随着未来干旱而增加或减少的物种子集，以及干旱和竞争对树种性能的双重影响。考虑到干旱和竞争对热带森林多样性和功能的重要性，其结果将是我们理解热带森林生态学以及更广泛的生态系统健康的基础。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

A major goal in ecology is to understand why different types of plants and animals occur where they do. This question is particularly important for tropical forests because they are home to most of the world's species and are essential for global carbon and nutrient cycles; they help control the atmosphere of the entire planet. In a sense, tropical plants are the "lungs" of the planet. Scientists are starting to think that drought is critically important in determining how well tropical forests "breathe". However, the evidence for this is still unclear. In this project, researchers will test how different tropical plant species respond to an ongoing, multi-year drought in Panama. Undergraduate and graduate students from the U.S. will participate in the project and receive training in how to conduct scientific research. In the context of a large-scale, long-term competition experiment, the PI will examine the role of a multi-year drought to test two predictions: 1) The strength of plant-plant competition increases with drought and varies with species identity. 2) Plant species that capitalize on drought will share a suite of plant hydraulic functional traits. By testing these predictions, the PI can provide a functional-mechanistic explanation for how different species respond to drought, and determine whether plant-plant competition intensifies the effects of drought. By examining the responses of more than 100 plant species and by relating those responses to a suite of functional characteristics for each species, this project will identify the subset of species that will likely increase or decrease with future droughts, as well as the dual effects of drought and competition on tree species performance. Considering the importance of both drought and competition to tropical forest diversity and function, results will be fundamental to our understanding of tropical forest ecology and, more generally, ecosystem health.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.