and abiotic conditions in mid and high elevation montane forests are dramatically
different from those in the lowlands. For example, lower temperature regimes
result in slower decomposition and nutrient mineralization rates.
At mid-elevation there are also important changes in the functional traits of tree species. For example, communities
dominated by species that form arbuscular mycorrhizal associations in the lowlands are replaced by those with
Montane forests are also likely to be strongly impacted by global climate change; recent research
in Central American forests indicates that climate warming is raising the elevation at which clouds form.
These changes are likely responsible for observed species migrations and are likely to have important long-term
effects on tree communities.>
We have established a network of twelve 1-ha forest dynamics plots
in the Fortuna and Palo Seco
montane forest reserves in western Panama. Our sites span gradients of elevation (850-1400 m),
and rainfall (3m - 6+m/yr) as well as a steep gradient in soil nitrogen and phosphorus availability. Plot data are being used to design experiments to
examine mechanisms determining range distributions of trees and to compare
the importance of constraints on recruitment success between high elevation
sites and lowland sites in central Panama.
In 2013-2014 we are working on the second (10 year) recensus of our plots, and on the long task of revising and finalizing
identifications of the 525+ tree species present within them. We are collaborating
on this project with faculty and students from the Universidad Autonoma de Chiriqui (UNACHI).