Do Lianas Cause Chronic Disturbance and Alter Successional Trajectories in Tropical Forests?

越来越多的证据表明，藤本植物(木本藤本植物)在数量丰富时，会扰乱树木再生，从而影响碳固存和物种多样性，从而极大地改变热带森林。由于藤本植物的丰度和生物量被认为会随着气候变化而增加，因此对藤本植物的生态及其在热带森林中的作用的研究现在至关重要。这项研究将测试一系列相互关联的假说，以确定藤本植物是否可以启动一个正反馈过程，从而推动热带森林朝着藤本植物永久改变的结构、物种组成和树木密度、多样性和生物量的方向发展。为了验证这些假设，研究人员将在巴拿马巴罗科罗拉多岛的一块50公顷的热带森林中永久标记、绘制位置图、测量直径并识别藤本植物，过去25年来，人们在那里对近25万棵树进行了研究。他们还将进行单独的、受控的藤本植物移除实验，以更机械地了解藤本植物与树木的相互作用。藤本植物对树木动态和森林更新的影响，以及藤本植物能否将热带森林演替从以树木为主的生态系统转向以藤本植物为主的生态系统的问题，对于全球变化对热带森林长期健康和维持物种多样性的潜在影响具有深远的重要性。除了直接测试这些问题，这项研究还将产生更广泛的影响，包括教育和国际能力建设，重点是培训来自美国和巴拿马的热带生物学本科生和研究生。

Growing evidence suggests that lianas (woody vines), when abundant, can substantially alter tropical forests by disrupting tree regeneration and thus impacting carbon sequestration and species diversity. Because liana abundance and biomass are thought to increase with climate change, studies on the ecology of lianas and their role in tropical forests are now critical. This research will test a series of interrelated hypotheses to determine whether lianas can set in motion a positive feedback process whereby tropical forests are driven toward permanently liana-altered structure, species composition, and reduced tree density, diversity, and biomass. To test these hypotheses, the investigators will permanently tag, spatially map the location, measure the diameter, and identify lianas in a 50 ha plot of tropical forest on Barro Colorado Island, Panama, where nearly 250,000 trees have been studied for the past 25 years. They will also conduct a separate, controlled liana removal experiment to gain a more mechanistic understanding of liana-tree interactions. The impact of lianas on tree dynamics and forest regeneration, and the question whether lianas can redirect tropical forest succession from tree-dominated to liana-dominated ecosystems, are of profound importance for the potential impact of global change on long-term tropical forest health and the maintenance of species diversity. In addition to testing these questions directly, this research will also have broader impacts, including educational and international capacity building focusing on training undergraduate and graduate students from both the United States and Panama in tropical biology.