Program Goal
Research provides scientific knowledge of terrestrial components of the global
carbon cycle – for the purposes of accurate predictions of atmospheric
CO
2 change, evaluating terrestrial sources and sinks for CO
2,
and assessing effectiveness of ecosystem processes for controlling and squestering
CO
2 –
thereby slowing the rate of atmospheric CO
2 increase.
Program Objectives
(1) To advance the scientific understanding of terrestrial processes
that regulate carbon balance of ecosystems, including mechanistic controls
on exchanges of CO2 with the atmosphere;
(2) To understand fundamental carbon cycling mechanisms of the atmoshere
and biosphere as a basis for enhancing carbon sequestration by terrestrial
ecosystems;
(3) To measure changes of carbon quantities of ecosystems in relation
to the rising concentration of atmospheric CO2, and altered
temperature and precipitation regimes;
(4) To model terrestrial carbon processes, and use terrestrial ecosystem
models coupled with atmosphere-ocean carbon models to estimate rate and
timing of atmospheric CO2 change.
Program Description and Components
Terrestrial Carbon Processes (TCP) research provides the scientific underpinnings
for predicting future concentrations of CO
2 in the atmosphere.
In particular, TCP research focuses on (i) understanding the processes
controlling exchange rate of CO
2 between atmosphere and terrestrial
biosphere; (ii) developing process-based models of atmosphere-terrestrial
carbon exchange; (iii) evaluating source-sink mechanisms for atmospheric
CO
2; and (iv) improving reliability of global carbon models
for predicting future atmospheric concentrations of CO
2. The
research focuses on natural systems that regulate the abundance of CO
2 in
the atmosphere, including the role of terrestrial ecosystems in determining
exchanges of CO
2 with the atmosphere. Focus of the research
is on the processes and mechanisms that influence quantities fixed by terrestrial
ecosystems, and the potential for long-term carbon sequestration is evaluated.
This research is distinct from, yet complimentary to continental scale
carbon cycle observations of the National Oceanic and Atmospheric Administration
(NOAA) and other laboratories.
BER's TCP research responds to the U.S. Carbon Cycle Science Plan, and
significantly contributes to the
Interagency
Carbon Cycle Implementation Plan. The research supports AmeriFlux
measurements and modeling, and experiments on the effects of CO
2 and
changing climate variables on plants and ecosystems. Research also investigates
plant physiological controls that affect exchange of CO
2 between
the atmosphere and terrestrial biota, changes of carbon content of plants
and soil, and mechanisms of carbon transformation in soil.
A major uncertainty of the greenhouse gas and potential climate change
issue is what happens to the excess CO
2 generated from the burning
of fossil fuels. Rate and magnitude by which excess carbon is assimilated
into sinks affects the balance that remains in the atmosphere. Terrestrial
ecosystems play an important role in this process and fundamental TCP research
provides the scientific foundation for estimating the capacity of ecosystems
to sequester and store the considerable quantities of CO
2 anticipated
from fossil sources in the future.
At the larger scale, the research focuses on ecosystem productivity and
structural and functional properties of ecosystems, including roles of
plant-animal-microbial communities that process carbon. Fundamental plant
processes (e.g., photosynthesis, carbon metabolism and water balance) and
ecosystem processes (e.g., productivity and nutrient turnover) are examined
as they might be affected directly by CO
2 and indirectly by
changing climate conditions. Components of field and modeling activities
include:
- Carbon (CO2) flux and biometric measurements in terrestrial
ecosystems for evaluating changes of carbon quantities.
- AmeriFlux,
the network of CO2 flux, for directly estimating net ecosystem
production (NEP), and carbon sequestration by terrestrial ecosystems.
- Experiments for determining effects of CO2, climate and
other environmental variables on carbon uptake, sequestration by ecosystems
(focus is on different environments and biogeochemical and climate-related
feedbacks); FACE represents multi-disciplinary experiments
to evaluate the responses of terrestrial plants and ecosystems to increased
concentrations of atmospheric CO2 and changing climate variables.
- Mechanistic terrestrial carbon models for evaluating the role of
the biosphere in atmospheric CO2 changes, and the influence
of climate and other feedbacks on the biogeochemical cycle of carbon.
Program Announcements
None at this time.
Program Linkages
The TCP research is central to DOE's policy concerns about excess CO
2,
which is the anticipated major human cause of climate change. Experiments
and measurements of TCP provide critical data for tracking atmospheric
CO
2 changes, and for quantifying the terrestrial term of the
excess CO
2 budget. TCP data contribute to integrated Programs
of the
U. S. Global Change Research Program, particularly
the "Carbon Cycle" interdisciplinary research element. The experiments
contribute measurably to IGBP research on Global Change and Terrestrial
Ecosystems (GCTE), and the AmeriFlux Network represents the North American
component of the international FLUXNET Program. Carbon Cycle research contributes
fundamental scientific information that underpins carbon sequestration
and management programs in the Office of Science and the Office of Fossil
Energy. TCP research contributes to the Administration's National Climate
Change Technology Initiative (NCCTI) to quantify carbon affects due to
carbon sequestration by terrestrial ecosystems. The TCP Program, especially
AmeriFlux, contributes to the planned North American Carbon Program.
Program Manager
Dr. Roger C. Dahlman
Climate and Environmental Sciences Division, SC-23.1
Department of Energy, GTN Bldg.
1000 Independence Ave, SW
Washington, DC 20585-1290
(301) 903-4951
Fax: (301) 903-8519
Internet: roger.dahlman@science.doe.gov