Ram Oren

Research Area(s): global change ecology
biogeochemistry
ecology
forest management and silviculture
terrestrial ecosystems
wetland ecology

With his graduate students, Dr. Oren quantifies the components of water flux in forest ecosystems and the influence of certain biotic and abiotic factors on water flux. 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 patterns and amounts of water used by forest ecosystems, and their spatial distributions. These variations influence the temporal and spatial partitioning of incoming radiation between latent and sensible heat. Changes in water use by forests, resulting from abiotic pressures, trigger biotic feedback responses, which may often cancel or amplify abiotic impacts. Using a local mass balance approach and detailed measurements of water flux and driving variables in the soil, plants, and the atmosphere, in forests from Brazil to Alaska, Dr. Oren evaluates the likely responses of different forest ecosystems to environmental change. Using the Free Air CO2 Enrichment facility, together with several AmeriFlux sites, Dr. Oren also quantify the carbon and water balance in forests under current atmospheric CO2 concentration and concentration projected in future atmosphere, and evaluate the effect of soil fertility on carbon sequestration and water yield in pine forests.

TEACHING (Spring 2010)

ENVIRON 213.01, FOREST ECOSYSTEMS,
ENVIRON 398.01, PROGRAM AREA SYMPOSIUM,
ENVIRON 398.03, PROGRAM AREA SYMPOSIUM,

Recent Publications (More Publications)

1. Domec, Jean-Christophe and Palmroth, Sari and Ward, Eric and Maier, Chris A. and Therezien, M. and Oren, Ram, Acclimation of leaf hydraulic conductance and stomatal conductance of Pinus taeda (loblolly pine) to long-term growth in elevated CO2 (free-air CO2 enrichment) and N-fertilization, PLANT CELL AND ENVIRONMENT, vol. 32 no. 11 (2009), ppt. 1500-1512 [abs]
   
2. Novick, K. A. and Oren, R. and Stoy, P. C. and Siqueira, M. B. S. and Katul, G. G., Nocturnal evapotranspiration in eddy-covariance records from three co-located ecosystems in the Southeastern US: Implications for annual fluxes, AGRICULTURAL AND FOREST METEOROLOGY, vol. 149 no. 9 (2009), ppt. 1491-1504 [abs]
   
3. Katul, Gabriel G. and Palmroth, Sari and Oren, Ram, Leaf stomatal responses to vapour pressure deficit under current and CO2-enriched atmosphere explained by the economics of gas exchange, PLANT CELL AND ENVIRONMENT, vol. 32 no. 8 (2009), ppt. 968-979 [abs]
   
4. Daly, Edoardo and Palmroth, Sari and Stoy, Paul and Siqueira, Mario and Oishi, A. Christopher and Juang, Jehn-Yih and Oren, Ram and Porporato, Amilcare and Katul, Gabriel G., The effects of elevated atmospheric CO2 and nitrogen amendments on subsurface CO2 production and concentration dynamics in a maturing pine forest, BIOGEOCHEMISTRY, vol. 94 no. 3 (2009), ppt. 271-287 [abs]
   
5. Novick, Kimberly and Oren, Ram and Stoy, Paul and Juang, Jehn-Yih and Siqueira, Mario and Katul, Gabriel, The relationship between reference canopy conductance and simplified hydraulic architecture, ADVANCES IN WATER RESOURCES, vol. 32 no. 6 (2009), ppt. 809-819 [abs]