PROGRAM TITLE:	Assessing Biogeochemical Fluxes from Agriculture 
and Rangelands
ACTIVITY STREAM:	Understanding
SCIENCE ELEMENTS:	Biogeochemical Dynamics and Ecological Systems 
and Dynamics

Agricultural Research Service

SCIENTIFIC MERIT:  Research emphasizes the assessment of biogeochemical 
cycling and partitioning of carbon, nitrogen, and other nutrients between 
agricultural and rangeland systems and the atmosphere.  Research is focus on:  
(1) sequestering and release of carbon in terrestrial pools and its interaction 
with the atmosphere, (2) carbon, nitrogen, and other nutrient cycles as they 
are influenced by anthropogenic activities, and (3) exchange of carbon dioxide, 
methane, and NÐcontaining gases between terrestrial ecosystems and the 
atmosphere including observation of interannual variation of these 
exchanges.  Results provide inputs to process models being concurrently 
developed from experimentally measured gas flux and nutrient cycling data.  
These models contribute toward the goal of providing global fluxes of gases 
from terrestrial systems integrated over scales consistent with Global 
processes as required by GCMs.
The program, being conducted cooperatively with university and federal 
scientists at more than a dozen locations, is structured around three major 
activities:  understanding basic processes, establishing site networks, and 
incorporating geographic information system technologies.  Research within 
each activity is organized around the three major focus areas identified in the 
preceding paragraph.
This research program is vital to understanding and predicting not only the 
fluxes of radiatively active gases from terrestrial ecosystems, but also the 
response of these systems to impending Global change phenomenon.
This program takes advantage of a long history of research on nutrient cycling 
by agricultural scientists to support agricultural production.  As the largest 
single agricultural research organization, the Agricultural Research Service is 
closely linked to the National and International scientific networks of these 
and other scientists.  Agricultural Research Service scientists have historically 
pioneered research in areas of nutrient dynamics and biogeochemical cycles.  
Consequently, close linkages are established to ARS scientists by many other 
Government agencies.
STAKEHOLDERS:  The research benefits all of society through application of 
research results to insure food and fiber production for the Nation on a 
sustainable basis.
POLICY RELEVANCE:  This research is linked with USDA agencies (FS, 
CSRS, and SCS) and with other CEES agencies as opportunities present 
themselves.  Benefits will primarily be scientific information on which to 
develop policies and aid decision making at local, regional, and national 
scales involving the impact of climate and global change on the sustainability 
of food and fiber supplies and the health of the natural resource base.
PROGRAM CONTACT:  R. Dennis Child    Phone (301)  504Ð5618     FAX   
(301) 504Ð6231