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

生态学家长期以来一直对热带森林中为什么有这么多种类的树木感到困惑；答案并不明显。最近的证据表明，隐藏在土壤中的疾病微生物可能在决定一个给定地区可以生长多少物种方面发挥重要作用。然而，这一假说缺乏严格的测试。该项目采用实验、植物病理学和尖端遗传学方法相结合的方法来测试土壤中树木和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。这项研究在收集了大量关于许多类型的基本上未知的病原体的分布、身份和宿主特异性的详细数据方面是不同寻常的。由于人为干扰和农业实践，土壤病原体物种组成的变化得到了很好的记录。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寻找更有效的保护和重新造林技术提供关键的见解。由于这个项目具有高度的协作性，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州植物园合作，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.