COLLABORATIVE RESEARCH: Pathogen-mediated negative feedbacks determine tropical tree species abundance

长期以来，生态学家一直对热带森林中为什么有如此多的树木种类感到困惑；答案并不明显。最近的证据表明，隐藏在土壤中的致病微生物可能在决定特定地区有多少物种可以生长方面发挥重要作用。不过，目前还缺乏对这一假设的严格检验。该项目采用实验、植物病理学和尖端遗传方法相结合的方法来测试树木与土壤中病原体之间的相互作用是否决定了巴拿马热带森林的树种组成。这项研究收集了大量关于许多类型的未知病原体的分布、特征和宿主特异性的详细数据，这是不寻常的。由于人为干扰和农业实践，土壤病原体的物种组成发生了变化。然而，人们对这种变化对土地恢复的影响知之甚少。这项研究将为科学家们寻找更有效的保护和重新造林技术提供重要的见解。由于这个项目是高度合作的，它还将为美国和拉丁美洲的学生提供植物和微生物生态学方面的广泛培训。最后，首席科学家将与密苏里植物园合作，公开展示土壤微生物对自然和农业植物群落的健康和可持续性的重要性。

Ecologists have long been puzzled about why there are so many species of trees in tropical forests; the answer is not obvious. Recent evidence suggests that disease microbes hidden in the soil may play an important role in determining how many species can grow in a given area. Rigorous tests of this hypothesis are lacking, though. This project employs a combination of experiments, plant pathology, and cutting-edge genetic approaches to test whether interactions between trees and disease agents in the soil determine tree species composition in tropical forests of Panama. The study is unusual in the amount of detailed data collected on distributions, identities, and host specificity of many types of largely unknown pathogens. Changes in species composition of soil pathogens as a result of human-caused disturbances and agricultural practices are well documented. However, the impact of such changes on land restoration is poorly understood. This study will provide critical insights to scientists as they search for more effective conservation and reforestation techniques. Because this project is highly collaborative, it will also provide broad training to U.S. and Latin American students in the ecology of plants and microbes. Finally, the lead scientists will work with the Missouri Botanical Garden to publically demonstrate the importance of soil microbes to the health and sustainability of both natural and agricultural plant communities.