Ram Oren

Nicholas Distinguished Professor of Earth Systems Science

With his graduate students, Oren quantifies components of the water cycle in forest ecosystems, and their responses to biotic and abiotic factors. Relying on the strong links between the carbon and water cycles, he also studies the components of the carbon flux and their response to these factors. Climate variability, including variations in air temperature, vapor pressure deficit, incoming radiation and soil moisture, and environmental change, including elevated atmospheric carbon dioxide, affect the intra- and inter-annual dynamics, and amounts of water used by forest ecosystems, and their spatial distribution, as well as carbon uptake and sequestration. In turn, the variation of water flux influence the temporal and spatial partitioning of incoming radiation between latent and sensible heat. The flow of water from soil through plant leaves into the atmosphere, and the exchange of water for CO2 absorbed from the atmospheric, are among the processes theoretically best understood in plant and ecosystem physiology. Using these theories, local mass balance approaches, and detailed measurements of water and carbon flux and driving variables in the soil, plants, and the atmosphere, Oren has been attempting to predict the likely responses of forest ecosystems, from the equator to the arctic circle, to environmental change and management.

Appointments and Affiliations

  • Nicholas Distinguished Professor of Earth Systems Science
  • Professor of Ecology
  • Professor in Division of Earth and Ocean Sciences

Contact Information

  • Office Location: A246A Lev Sci Res Ctr, Durham, NC 27708
  • Office Phone: +1 919 613 8032
  • Email Address: ramoren@duke.edu


  • B.S. Humboldt State University, 1978
  • M.S. Oregon State University, 1980
  • Ph.D. Oregon State University, 1984

Courses Taught

  • ENVIRON 899: Master's Project
  • ENVIRON 898: Program Area Seminar
  • ENVIRON 593: Independent Studies and Projects
  • ENVIRON 503: Forest Ecosystems
  • ENVIRON 497: Communicating Research in Environmental Sciences and Policy
  • ENVIRON 496: Advanced Research in Environmental Sciences and Policy
  • ENVIRON 393: Research Independent Study

In the News

Representative Publications

  • Ward, Eric J., Ram Oren, Hyun Seok Kim, Dohyoung Kim, Pantana Tor-Ngern, Brent E. Ewers, Heather R. McCarthy, et al. “Evapotranspiration and water yield of a pine-broadleaf forest are not altered by long-term atmospheric [CO2 ] enrichment under native or enhanced soil fertility.” Global Change Biology 24, no. 10 (October 2018): 4841–56. https://doi.org/10.1111/gcb.14363.
  • Henriksson, Nils, Lasse Tarvainen, Hyungwoo Lim, Pantana Tor-Ngern, Sari Palmroth, Ram Oren, John Marshall, and Torgny Näsholm. “Stem compression reversibly reduces phloem transport in Pinus sylvestris trees.” Tree Physiology 35, no. 10 (October 2015): 1075–85. https://doi.org/10.1093/treephys/tpv078.