PROGRAM TITLE: 	Effects of Global Changes on Agroecosystems 
ACTIVITY STREAMS: 	Processes, Assessments, Model/Predict 
SCIENCE ELEMENT: 	Ecological Systems and Dynamics 
BUDGET LINE ITEMS: 	EPA, ORD, Stratospheric Modification, 
GlobalÊClimate;ÊEPA, ORD, Stratospheric Modification, Stratospheric Ozone


SCIENTIFIC MERIT: Determine: (1) the probable magnitudes and rates of 
human-induced change in ecological systems; (2) how these changes 
can be distinguished from natural fluctuations; and (3) which ecological 
systems and species are changes most likely to affected and what attributes of 
importance to humans will be at risk. The objective of this research is to 
develop risk characterizations of the consequences of global change for the 
world's most important crops. Specific questions addressed include: 1) How 
sensitive are crop productivity and cropping systems to UV-B radiation, 
increased CO2 and temperature, and changing precipitation patterns on a 
regional basis? 2) What is the global flux of methane emissions from rice 
fields? 3) What options can be identified to minimize methane emissions 
without reducing rice yields. The focus will be on key global crops. Initially, 
the irrigated rice cropping system is emphasized. The research is being 
conducted at the International Rice Research Institute (IRRI) in the 
Philippines, with further collaboration with leading rice research groups in 
Japan, Korea, China, Malaysia, India, Philippines, United States and Europe. It 
includes experimental field and laboratory studies and modeling studies, 
primarily based on ORYAZA1, a physiological simulation model, and 
ecosystem models which integrate the responses of rice and components of 
the rice cropping system to integrate and extrapolate the results to the 
regional level. This research will characterize on regional and global scales 
the risks to rice productivity from stratospheric ozone depletion and climate 
STAKEHOLDERS: Partnerships are in place with researchers in 6 Asian 
countries and the International Rice Research Institute. Research is 
coordinated with IGBP/GCTE. Collaboration has also occurred with the 
USDA/ARS, NCAR, and scientists at several major U.S. universities.
POLICY RELEVANCE: Contributes to the 1995 and subsequent IPCC 
Assessments as well as the following major milestones in the U.S. GCRP:
PROCESS STUDIES; Ecological Systems, Species Responses, 1991-1995 
Milestones: Physiological sensitivity to climatic variability established for 
selected economically important species, and Sensitivity of selected rice 
cultivars to UV-B established; 1996-2000 Milestones: Physiological sensitivity 
of economically important species to climatic variability continued, and 
Sensitivity of rice yields to increased UV-B modeled globally;
MODELING; Greenhouse Gases, 1996-2000 Milestone: Dynamic global carbon 
models developed; Economics and Other Human Systems, 1996-2000 
Milestone: Models relating agricultural activity to environmental conditions 
refined and expanded;
ASSESSMENT; 1996-2000 Milestone: Integrated international assessments 
of global change continued. 
PROGRAM CONTACT: Peter Beedlow, U.S. EPA, 200 SW 35th St, Corvallis, 
OR 97333   (503) 754-4634