I am a systems ecologist, and all of my life's varied research reflects my interest in understanding and developing computer simulation models of how complex systems of nature and humans and nature operate. My original work was in relatively undisturbed rivers and lakes and then in estuaries. Subsequently, I became increasingly interested in studying systems of humans and nature using ecosystems perspectives, that is, by studying material and energy flows. Most of my work these days is in the tropics. Increasingly, I am interested in synthesizing with my wife GIS and simulation modeling to make what we call geographic modeling. For example, I have recently completed a book synthesizing environmental, agricultural and economic information for the country of Costa Rica on a 1 km by 1 km grid cell basis. Nevertheless, I continue to work on various aspects of natural tropical forest and temperate stream ecosystems. For example, my students (both grad and undergrad) and I have recently undertaken a new project in a Puerto Rican rain forest using professional free climbing equipment and a LiCor CO2 meter to measure photosynthesis and respiration of the forest at 100 meter altitudinal levels from the bottom to the top of the Luquillo Mountains.
E-mail: Charles Hall