DISSERTATION RESEARCH: The influence of soil fertility on tropical tree species carbon and nutrient storage: A comparison between lowland and montane forests

热带雨林养育着丰富多样的生命，包括50,000多种树种。这种多样性的一个关键似乎是不同的物种生长在不同的土壤上。本项目将探索导致物种以这种方式划分热带雨林栖息地的植物功能特征。研究将检验一个假设，即一个树种将木材碳水化合物和营养物质储存在木材中，然后再将它们移回树木其他部分使用的能力，决定了一个物种在森林中的位置，沿着土壤肥力从低到高的梯度，这一假设尚未在热带森林中得到验证。这两个主要目标是比较1)巴拿马低地和山地热带森林中不同自然群落树木中碳水化合物和营养物质的储量，沿着平行的土壤肥力梯度，巴拿马低地和山地热带森林中的碳水化合物和营养物质的储量，以及2)生长在不同土壤上的相关树种的树苗对实验性落叶反应重新调动养分储量的能力。该项目将培训一名来自美国的女博士生，并扩大与巴拿马当地公立大学的学生和教职员工的国际科学合作。作为这一合作的一部分，这名博士生将指导一名巴拿马本科生的高级论文项目，并担任巴拿马一门本科生实地课程的助教。在美国，这位博士生将在伊利诺伊州厄巴纳中学参加为期六周的植物iView项目，以志愿者的身份分享她的植物生物学知识。除了这种教育培训和公共宣传外，该项目还将通过增加对如何维护生物多样性的理解而造福社会。

Tropical rainforests support a rich diversity of life including over 50,000 tree species. One key to this diversity appears to be that different species grow on different soils. This project will explore the features of plant function that cause species to divide up the rainforest habitat in this way. Research will test the hypothesis that the ability of a tree species to store wood carbohydrates and nutrients in wood and then move them back out again for use in other parts of the tree determines where a species is found in the forest along a gradient from low to high soil fertility, a hypothesis not yet tested in tropical forests. The two main objectives are to compare 1) the stocks of carbohydrates and nutrients in wood in trees in different natural communities along parallel gradients of soil fertility in lowland and montane tropical forests in Panama, and 2) the ability of the saplings of related tree species that grow on different soils to remobilize stocks of nutrients in response to experimental defoliation.This project will train a female Ph.D. student from the U.S. and expand international scientific collaboration with students and faculty from a local public university in Panama. As part of this collaboration, the Ph.D. student will mentor an undergraduate Panamanian student on a senior thesis project and serve as the teaching assistant for an undergraduate field course in Panama. In the U.S., the Ph.D. student will share her knowledge of plant biology as a volunteer in the Plants iView program, a six-week, after school, outreach experience at Urbana Middle School in Illinois. Besides this educational training and public outreach, the project will also benefit society by increasing understanding of how to maintain biodiversity.