Steep gradients in temperature and rainfall and Earth's highest biodiversity make this a perfect laboratory for studying species distributions and climate change. Our current project involves looking at the factors controlling tree community composition and diversity along a transect running from the Amazon lowlands to above tree line in the Andes.
There are as many species of trees in a hectare of tropical rain forest as there are in all of North America.
The Amazon is our lab for asking why. My students and I have studied the role of life history trade offs in maintaining diversity in tropical forests, continental-scale patterns of tree distributions and species diversity, landscape-level patterns of forest communities, including bamboo forests and swamp forest, and also the role of animals in the maintenance of diversity in tropical forests.
Theories of community structure are usually tested using space as a proxy for time. Paleoecology allows us to look at time directly. Our work uses a network of lakes ranging from above tree line in the Andes down to the lowlands to reconstruct species distributions and plant communites for the area going back 43,000 years. We also look at the historical role of humans in tropical ecosystems by analyzing charcoal and crop pollen. The work also ties together climate change, humans, and past species distribution with an eye towards predicting how these ecosystems will change under scenarios of future climate change.