Biodiversity: Lars O. Hedin

November 15, 2011 "Individuals, Ecosystems, and the Land Carbon Sink" with Lars O. Hedin, Professor of Ecology and Evolutionary Biology, Director of Program in Environmental Studies, Princeton UniversityIn this talk Professor Hedin will address the issue of scaling ecological and evolutionary properties of individual organisms to the global biosphere. He argues that ecosystem level properties are not sufficient for understanding the future land carbon sink. Instead, some of the most fundamental determinants of land carbon exchange depend on properties and interactions that occur at scales of individual organisms and that are expressed in local environments. Such scaling of organismal properties to global dynamics represent an emerging challenge to our conceptual and numerical models of the land biosphere.

Lars Hedin is particularly interested in understanding how biogeochemical cycles are changing globally in response to large-scale modern human activities, and how such changes influence evolutionary environments of plants and microbes. While it is difficult to find ecosystems that are entirely free of human disturbances, he has for over a decade studied remote forests in southern Chile and Argentina that are historically free from atmospheric pollution, cutting, and other major human influences. These studies offer a "baseline" for how forests function naturally as biogeochemical systems, against which mechanisms and extents of human impacts can be better understood. He is presently expanding these studies to include tropical forests across the Hawaiian archipelago, the Amazon basin, Panama, and locations in Africa.

The Biodiversity, Ecology, and Global Change lecture series is sponsored by the Harvard University Center for the Environment with generous support from Bank of America. The lecture will be followed by a reception.