PROGRAM TITLE:	Response of Vegetation to CO2 and Climate
ACTIVITY STREAM:	Processes, Modeling
SCIENCE ELEMENT:	Biogeochemical Dynamics, Ecological 


DESCRIPTION:  Goal of this research is to understand and predict combined 
effects of altered climate and the increased concentration of CO2 on 
vegetation.  Specific objectives are to understand how plants respond to these 
variables; the role of vegetation in the global carbon cycle; and feedbacks of 
the terrestrial biosphere on climate.  Products derive from long term field 
experiments designed to evaluate the effects of systematic manipulations of 
atmospheric CO2 and climate on plant and ecosystem processes.  The 
information is used to develop biophysical and ecosystem models for 
evaluating vegetation changes in relation to altered climate conditions, and 
the mechanisms of carbon sequestration by terrestrial ecosystems. 

This Program has pioneered the Free Air CO2 Enrichment Experiment 
(FACE) approach - a leading protocol for evaluating the effects of CO2 and 
climate change on crops and ecosystems in a consortium of worldwide 
experiments.  DOE/FACE research provides engineering/scientific support to 
the consortium, which includes terrestrial "flagship" experiments adopted by 
IGBP/GCTE.  The research is coordinated with USDA, EPRI.  Research Centers 
in five countries are deploying this approach to produce field data on plant 
and ecological processes.  Data on the combined influence of CO2 and climate 
factors on photosynthesis, transpiration, respiration, growth and other 
parameters are produced for native and crop species, and for selected 

STAKEHOLDERS: Results contribute to assessments of benefits or impacts of 
increasing greenhouse gases and climate change on ecosystems.  
Comprehensive assessments (e.g., domestic and IPCC) use scientific 
information produced by this research.   Domestic (e.g., joint NSF, USDA and 
Forest Service research) and International Research programs (e.g., "flagship" 
experiments of the IGBP) have vital interests in both protocols and research 
results from FACE studies.  A growing segment of scientists depends on 
experimental protocols and technical expertise developed and implemented 
by the DOE FACE Program.

SHORT-TERM POLICY PAYOFFS: This Program produces scientific 
information on the "biological effects of global change" needed for short-term 
policy analysis.  (1) Data and models are developed for evaluating ecological 
impacts and/or benefits of CO2 and climate change, including measures of 
ecosystem process and sustainability.  (2) Products are applicable to IPCC 
assessments of ecological impact, and for examining the issue of missing 
carbon in terrestrial environments.   (3) Critical information is provided for 
(a) making accurate estimates of future atmospheric CO2 concentration, (b) 
deriving mitigation offsets for CO2 as part of the U.S. Government Climate 
Change Mitigation Strategy.  The research contributes scientific information 
for analyzing greenhouse gas policy issues of the Climate Change Treaty, and 
the atmospheric CO2 stabilization study of IPCC. 

PROGRAM CONTACT:  Roger C. Dahlman, DOE, ER-74, Washington, DC 
20585, 301-903-4951