PROGRAM TITLE:  	Atmosphere/Biosphere Gas and Energy Exchange 
(ATBIOX)
ACTIVITY STREAMS:  	Process/Observation, Modeling
SCIENCE ELEMENT:  	Biogeochemical Dynamics  
 
 U.S. DEPARTMENT OF AGRICULTURE
Forest Service
 
DESCRIPTION:  Research emphasizes the linkages and interdependency 
between ecosystem cycles including carbon sequestration and other means for 
mitigating or adapting to global change.  This FSGCRP Program Element will 
encompass all major ecosystems and climates that contain important natural 
resources, such as timber, water, rangeland, wildlife, and recreational 
resources.
 
ECOSYSTEMS AND SOILS--Research examines ecosystems and soils through 
the way in which climate and atmospheric chemistry shape and are shaped by 
the biological world.  The research is conducted at scales from the regional to 
local.  It focuses on (1) the carbon cycle and carbon budget with particular 
attention to the flux of carbon between soils, water, the atmosphere, and the 
biosphere; (2) greenhouse gas (CO2, CH4, N2O, H2O) exchanges with 
terrestrial ecosystems; (3) nutrient cycles and energy flows, and (4) regional 
and local climate change scenarios. 
 
A number of methodologies and modeling techniques are applied to 
ATBIOXÊ research.  Measurements of the atmosphere adjacent to plants and 
communities are currently being made to determine biogenic gas fluxes- 
especially carbonÊdioxide and methane- and to monitor ozone and acidic 
deposition at manyÊlocations.  Chamber experiments provide these data and 
UV-B radiation as well as information on increased insect stress.  Soils are 
monitored to determineÊ trends in carbon storage and to develop an 
understanding of the processes that control the flux of carbon between soils, 
aquatic systems, the atmosphere, and the biosphere.  
 
Mechanistic models for individual species, functional groupings, and 
specificÊecosystems are under development to describe processes of carbon 
sequestration and allocation, water balance, and nutrient cycles.  
Biogeochemical soil models that couple climate to nutrient budgets, soil 
organisms, soil structure,Êfunction, and productivity are being developed.  
Climate change scenarios and carbon dioxide levels and distribution are 
applied to predict future vegetation and productivity of forests and 
rangelands in the U.S.  Regional adaptations to global climate scenarios are 
provided through local and mesoscale meteorologyÊ modeling.
 
WOOD -- Wood in use is an important adjunct to living ecosystems in 
mitigatingÊ the adverse impacts of global change phenomena.  Sequestration 
of carbon inÊvirgin and recycled products is a major factor in the carbon cycle.  
If wood in use is maintained in service for as long as the normal growth 
rotation forÊ trees the sequestration of carbon per rotation is extended by a 
factor of 2.5.Ê Use of wood as a replacement for fossil fuel, and re-growing 
wood eliminatesÊ atmospheric accumulation of CO2 from fossil fuel and 
because of its lowÊ energy intensity, wood may be used as a material to 
conserve energy.  RecyclingÊ wood increases carbon sequestration through 
extension of service life andÊ conserves the wood resource with less 
expenditure of energy.
 Ê   
This FSGCRP Program Element is vital to understanding and predicting theÊ 
structure and composition of future ecosystems.  Research which quantifiesÊ 
carbon sequestration in biomass, organic matter, the soils of forests andÊ 
related ecosystems, and wood in use will be accelerated.  Forests are a majorÊ 
repository of carbon taken from the atmosphere.  Understanding the carbon 
cycle  and its interrelationship with nutrient, water, and energy cycles is vital 
toÊ determining the dynamics of the global carbon budget.  This program is 
criticalÊ to understanding and predicting CO2, CH4, and sensible and latent 
heatÊ fluxes in changing land use patterns.  Of special interest is the role andÊ 
interactions of mycrorhizal fungi and other organisms in the rhizosphere 
withÊ host and associated environments.
STAKEHOLDERS:  Cooperators are DOT, EPA, DOE, NSF, NASA, U.S. 
Industries, Canada Department of Energy, Mines, and Resources
 
Primary beneficiaries are consumers, industry and other researchers.
 
SHORT-TERM POLICY PAYOFFS:  Information to hold 1990 levels of carbon 
emissions through the year 2000.