Seasonally dry tropical forests differ from rain forests in that they experience lower total rainfall, which is concentrated in one or more wet seasons that alternate with periods of little to no rain. In this talk, I will discuss a decade of observations from a seasonally dry forest in Costa Rica with data from Puerto Rico, Colombia, and Mexico. The overall goal of these studies is to understand how dry forest composition and dynamics change in relation to intra- and interannual variability in rainfall, and along geographic gradients in edaphic properties and successional age. I will conclude with a call for stronger collaboration among researchers and land managers who work in these unique and threatened ecosystems.