Tropical forest responses to Global change: Evidence from the Luquillo Experimental Forest

Background/Question/Methods

The Luquillo Experimental Forest (LEF) is located in the Luquillo Mountains in northeastern Puerto Rico.  The spatial and temporal variability in the climate of the Lu­quillo Mountains is influenced by large-scale movements of air masses, extreme events, and regional and global climate change.   Understand­ing the way in which species and ecosystems respond to gradients of climate and land use intensity is vital to the sustainability of populations, water resources, and ecosys­tem services. In the Luquillo Mountains these patterns are expressed in the context of the rich biodiversity of the trop­ics and the complex interplay of land use, hurricanes, and plant and animal responses to resources and competition.  This presentation will focus on how long-term data and manipulative experiments conducted at LEF provide deeper mechanistic understanding of the controls on the structure and functioning of these tropical forests in the context of climate change.  The presentation will also focus on the socio-ecological context in which the LEF is situated thus, relating socioeconomic implications to climate change projections.

Results/Conclusions

Climatic variability at LEF manifests as gradients that are correlated with elevation, slope, aspect, or land use history.  Efforts to understand the spatial variability in the forest ecosystems at LEF often recognize the existences of these gradients. The biota responds to abiotic gradients in the LEF and interacts with them to produce observable ecological patterns.  As the landscape surrounding LEF is increasingly urbanized, there is disruption of hydrological systems, introduction of nonnative species, and interruption of nutrient cycles, which collectively result in changes in the services that forests provide.  The impacts of urbanization are further compounded in the context of global change as intensive land development, high coastal population density, and large tourism-based industry effects intensify the vulnerability of Puerto Rico to climatic variability, given its limited human and capital infrastructure to address such problems.  In addition, changes in extreme weather patterns, including an increase in hurricane intensity and more frequent drought events are projected to alter the distribution of biota in this tropical forest.