I am a limnologist/paleolimnologist with special interests in tropical and subtropical lakes and watersheds. My research and teaching address interactions among climate, environment, and humans.

I’ve done fieldwork in Mexico, Guatemala, Panama, Venezuela, Bolivia, Ecuador and the Galapagos Islands, Haiti, Dominican Republic, China, Cambodia, and Florida.  I serve as Director of the Land Use and Environmental Change InstituteI am Co-Editor-in-Chief of the Journal of Paleolimnology.


Some of the topics I’ve investigated include:

1) recent human-mediated changes in Florida lakes

2) historical ecology of the Maya Lowlands

3) Pleistocene/Holocene paleoclimate of the circum-Caribbean

4) environmental history of the Bolivian Altiplano

5) paleoecology of Yunnan Province, China

5) history of El Niño

6) 210Pb dating

7) biological accumulation of 226Ra.