Department of Earth and Environmental Science

Arthur H Johnson

Interim Chair; Professor and Graduate Chair
Department of Earth and Environmental Science
University of Pennsylvania
240 S. 33rd Street
Hayden Hall
Philadelphia, PA 19104-6316

B.A. Middlebury College (1970)
M.A. Dartmouth College (1972)
Ph.D. Cornell University (1975)

Research Interests

Our research program addresses nutrient cycling in forests, primarily (1) the proximate and ultimate sources of macronutrients necessary for forest growth, and (2) the role of nutrients in limiting growth. As a new undertaking, we began a study of mummified forests of Eocene age (42 Ma) in the Canadian High Arctic. The exceptional preservation of the wood, litter, seeds, roots, cones and soils of these floodplain forests presents a unique opportunity to view life at a time when the planet was much warmer (and more productive).