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

University Of Wisconsin-Milwaukee, Milwaukee WI

Investigators

Abstract

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.