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Now available in PDF format: Abstract Book [7.4 Mb] (posted 10 November 2005)

Abstracts for Posters

Carbon (P-CA)

Sub-Theme 1: Sequestration in Ecosystems

P-CA1.1

Using Ecosystem Models to Inventory and Mitigate Environmental Impacts of Agriculture

Stephen Del Grosso, USDA/ARS, NREL/CSU, delgro@nrel.colostate.edu

Steve Ogle, NREL/CSU

William Paron, NREL/CSU

Keith Paustian, NREL/CSU

Ronald Follett, USDA/ARS

As a provider of climate change information, the presenter will discuss how ecosystem models can be used to asses and mitigate some environmental impacts of agriculture. Agriculture is the source of ~20% of global radiative forcing from the most important long-lived greenhouse gases (GHG's): carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O). Agriculture is a relatively small source of CO₂, but is responsible for ~50% and ~70%, respectively, of the anthropogenic emissions of CH₄ and N₂O. Agriculture is also the primary contributor of eutrophication of aquatic systems from nutrients that are runoff or leached from cropped fields into water ways. Thus, there exist potential to mitigate the impacts of agriculture on GHG emissions and water quality. The authors have developed inventories to estimate national emissions under present conditions which can also be used to identify areas that have large mitigation potential. For example, carbon (C) sequestration in agricultural soils has been suggested as a way to reduce national GHG emissions but inventories generated by the authors show that CO₂ emissions from histosol (organic soil) cropping nullifies >50% of the C sequestered in non-histosol cropped soils even though histosols occupy <1% of total US cropped land. Because it is not feasible to measure emissions at regional and larger scales, national inventories employ models. The authors are using the CENTURY and DAYCENT ecosystem models to estimate emissions from major cropping systems for the US national inventory. Models used to establish emissions under current management practices can also be used to compare alternative management scenarios intended to reduce emissions. For example, projected crop yield, soil C, and GHG outputs from CENTURY and DAYCENT have been linked with economic models to evaluate the costs/benefits of competing management strategies at the global scale. Although the use of ecosystem models in GHG inventories has increased confidence in emission estimates, there remains considerable uncertainty regarding both the estimates of GHG emissions under typical management practices and the extent to which these can be reduced under alternative management scenarios. Inventories can be improved and uncertainties reduced by increasing resources to collect field data for model/data comparisons and to acquire more refined activity data needed for model inputs.

[Poster PDF]

P-CA1.2

Renewable Energy as an Emission Control Alternative: Agricultural and Forestry Sector Roles

B.A. McCarl, Department of Agricultural Economics, Texas A&M University, mccarl@tamu.edu

J.C. Cornforth, Department of Agricultural Economics, Texas A&M University

R. Ismailova, Department of Agricultural Economics, Texas A&M University

W. You, Department of Agricultural Economics, Texas A&M University

M. El Halwagi, Department of Chemical Engineering, Texas A&M University

T. Mohan, Department of Chemical Engineering, Texas A&M University

X. Qin, Department of Chemical Engineering, Texas A&M University

One potential way of reducing net greenhouse gas emissions is through the use of renewable energy sources. Agriculture and forestry are important potential producers of renewable energy. Plant based materials from agriculture and forestry can be used directly as input to electricity generation or may be transformed into liquid fuels. Use of such feedstocks constitutes an opportunity to reduce net carbon emissions as plant growth removes carbon from the atmosphere via photosynthesis and then combustion releases that carbon. As a consequence, agriculture and forestry based feedstocks provide greenhouse gas recycling with the potential for reduced emissions relative to use of conventional fossil fuels. The net greenhouse gas balance when employing such strategies depends upon the amount of fossil energy and associated greenhouse gas related emissions that are incurred in growing, transporting and transforming the plant based feedstocks into energy.

This presentation reports on the prospects for agriculture and forestry playing a major role in energy generation. Pathways are considered for the development of electrical energy, gasoline replacements, and diesel replacements. Feedstocks can arise from crop and logging residues, energy crops, conventional crops, and agricultural oils. Results will be presented from a comprehensive consistent appraisal across all of these feedstock/energy replacement possibilities. Appraisal results will be presented on greenhouse gas efficiency, environmental impacts including air quality and economic conditions under which the renewable possibility makes sense in terms of energy prices and greenhouse gas offset prices.

[Poster PDF]

P-CA1.3

Estimating U.S. Forest-Agriculture Climate Change Mitigation Opportunities at the National and Regional Scales using Economic, Policy, and Co-Benefits Criteria

Brian Murray, RTI International, bcm@rti.org

Bruce McCarl, Texas A&M University

Kenneth Andrasko, U.S. Environmental Protection Agency

Benjamin DeAngelo, U.S. Environmental Protection Agency

Brent Sohngen, Ohio State University

U.S. forest and agricultural lands comprise a net carbon sink of 830 Tg CO₂ equivalent per year (for 2003), 90 percent of which is in forests, and offer significant potential for further greenhouse gas (GHG) mitigation. Decision makers require data and enhanced tools to evaluate mitigation options in terms of their magnitude, location, activity mix, timing, costs, and other (non-GHG) co-benefits. This information is needed at various scales: project, regional, and national.

Biophysical mitigation potential from forestry and agriculture is large, but only some fraction may be achieved by landowners under certain policy assumptions (e.g., eligibility restrictions), and economic incentives (e.g., carbon prices). The price-endogenous Forest and Agricultural Sector Optimization Model (FASOMGHG) is used to assess mitigation potential through the lens of economic, climate policy (e.g., baseline, leakage), and co-benefit (e.g., water quality) factors. Results for 2010-2110 (and focus years 2015, 2025, and 2055), are presented for six scenarios covering constant and rising GHG prices; fixed national mitigation levels; selected mitigation activities; and various incentive payment systems.

GHG reduction incentives can generate total national mitigation—relative to the baseline—averaging 630 Tg CO₂/yr (170 Tg C) in the first decade, 655 Tg CO₂/yr by 2025, declining to 85 Tg CO₂/yr by 2055, under a constant $15 t/CO₂ Eq scenario. The optimal portfolio and timing of mitigation is affected by GHG prices. At low GHG prices (≤$5/t CO₂ Eq.) and in early years, carbon sequestration in agricultural soils and in forest management dominate; afforestation dominates at middle to higher prices (≥$15/t CO₂ Eq.) to 2050; but the GHG benefits of these options get reversed by 2055. Biofuels dominate the portfolio at the highest prices ($30 and $50/t CO₂ Eq.) and in years beyond 2050. Mitigation potential is not regionally uniform. The South-Central, Corn Belt, and Southeast regions possess the largest GHG competitive potential; the Rockies, Southwest, and Pacific Coast the least. Incentive structures are important. If a national GHG mitigation quantity in a given year is an objective, but economic incentives do not continue after that date, then carbon sequestered in previous decades may be completely reversed. Leakage of GHG benefits to other regions may be significant if only selected activities (e.g., afforestation) are eligible for mitigation, and may vary by activity, region, and over time. GHG mitigation can have substantial non-GHG environmental co-effects. Even a low GHG price (e.g., $5/tonne) can induce changes in tillage practices and soil carbon sequestration, and reduce erosion and nutrient run-off.

[Poster PDF]

P-CA1.4

A Modeling Framework to Relate Agricultural Practice, Land-Use Change, Energy Use, and
Greenhouse Gas Emissions on Agricultural Lands in the USA:
Integrating Carbon Accounting with Survey Data, Remote Sensing, and Economic Modeling

Tristram West, Oak Ridge National Laboratory, westto@ornl.gov
Gregg Marland, Oak Ridge National Laboratory
Craig Brandt, Oak Ridge National Laboratory
Daniel De La Torre Ugarte, University of Tennessee
James Larson, University of Tennessee
Budhendra Bhaduri, Oak Ridge National Laboratory
Sally Mueller, Oak Ridge National Laboratory

Aarthy Sabesan, Oak Ridge National Laboratory
Chad Hellwinkle and Brad Wilson, University of Tennessee

A spatially-explicit modeling framework is currently being developed to monitor and model changes in greenhouse gas emissions from U.S. agricultural lands, including carbon sources and sinks, at the county scale. National survey data are being combined with greenhouse gas coefficients to estimate
lateral transport of carbon in agricultural products and the net C-equivalent flux of greenhouse gas emissions to the atmosphere. The primary data used for these estimates are being linked within a larger framework to facilitate revision on a regular basis. Agricultural input data and greenhouse gas coefficients are being combined with an agricultural economic model to model changes in land use, energy use, and greenhouse gas emissions that might occur on agricultural lands following changes in energy, agricultural, or climate change policies; or incentives that might be provided for carbon sequestration. With respect to carbon uptake, transport, and respiration, preliminary estimates for 2000 indicate that 495 Tg C were taken up from the atmosphere by agricultural crops, of which 209 Tg C were harvested and transported laterally throughout the country and then respired by livestock (77 Tg C) and humans (31 Tg C). Annual changes in soil carbon and the energy and emissions associated with agricultural inputs are also being monitored, and preliminary results will be presented. The estimates provided here are delineated spatially at the county level. Methods for delineating carbon transport and
greenhouse gas emissions at higher resolutions using remote sensing are being developed. This framework will provide information on changes in land use and associated changes in carbon sources and sinks, greenhouse gas emissions, and energy use that would accompany proposed changes in policy.

P-CA1.5

Determining the Long-Term Impact of Bioenergy Crops on the Global Warming Potential of Energy Use

Paul R. Adler, Pasture Systems and Watershed Management Research Unit, USDA-ARS, University Park, PA, paul.adler@ars.usda.gov

Steven J. Del Grosso, Soil Plant Nutrient Research Unit, USDA-ARS; Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO

William J. Parton, Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO

William E. Easterling, Institutes of the Environment, Pennsylvania State University, University Park, PA

As a provider of climate change information, the presenter will describe a framework to assess the impact of different bioenergy cropping systems (corn, soybeans, alfalfa, switchgrass, reed canarygrass, and hybrid poplar) on the global warming potential (GWP) of energy use and examine how the long-term impact of those predictions vary with climate change. Reducing the net GWP of energy use is a major factor driving interest in biofuels. Bioenergy cropping systems vary in contribution to the GWP due to the following: crop yield and resulting quantity of fossil fuels displaced by the biofuels produced, change in soil organic carbon and belowground biomass carbon, fossil fuels used in feedstock transport to the biorefinery, conversion to biofuel and subsequent distribution, N₂O and CH₄ emissions, CO₂ emission from N fertilizer manufacture, and fuel used by agricultural machinery for tillage, planting, fertilizer/pesticide application, harvesting, and drying corn grain. To conduct a life cycle analysis of the GWP of bioenergy
cropping systems, DAYCENT is used to model the dynamic sources and sinks of greenhouse gases (GHGs). Cropping system practices, such as tillage, plant life cycle, and N fertilizer use have a significant impact on GHG emissions. DAYCENT can integrate climate, soil properties, and land use and can dynamically evaluate the impact of cropping systems on crop production, soil C, and trace gas fluxes, factors critical to conducting a full C cycle analysis of bioenergy cropping systems. This approach to determining the GWP of bioenergy cropping systems can be used to extend evaluations from local to regional scales across the United States. By determining the optimal portfolio of bioenergy crops grown regionally, reduction in GWP can be maximized. This analysis can be expanded to include the impact of climate change on crop production and GWP. Weather data driving climate change scenarios are taken from VEMAP for the baseline scenario with no climate change and from the Canadian Centre for Climate Modeling and Analysis (CGCM1model) and Hadley Centre for Climate Prediction and Research, UK, (HADCM2 model) for the climate change simulations where CO₂ was assumed to double from 2004 - 2100. This modeling approach permits determination of the GWP of bioenergy cropping systems across the United States, including the effect of climate change.

[Poster PDF]

P-CA1.6

COLE: Carbon OnLine Estimation Web Tool for Continental U.S. Forest Ecosystems

Linda S. Heath, USDA Forest Service, Northeastern Research Station, P.O. Box 640, Durham, NH 03824Lheath@fs.fed.us

Paul C. Van Deusen, National Council of Air and Stream Improvement

Michael P. Spinney, National Council of Air and Stream Improvement

Jeffrey H. Gove, USDA Forest Service, Northeastern Research Station

James E. Smith, USDA Forest Service, Northeastern Research Station

The Carbon OnLine Estimator (COLE; http://ncasi.uml.edu/COLE/) Web tool enables a user to choose a part of or all the forested area of the continental United States, designate subcategories of interest such as owner, forest type, and productivity class, and the tool returns requested reports, estimates, and maps of forest carbon sequestration for that area. Estimates are calculated using traditional forest inventory data collected by the USDA Forest Service, Forest Inventory & Analysis Program, augmented by other ecological data. COLE allows users unfamiliar with these data to produce customized analysis in a short amount of time. The carbon estimates have been used in a number of formats of interest to decision makers, including: greenhouse gas emissions and sinks carbon inventories at the national- and state-level, Montreal Process criteria and indicators for sustainability for maintenance of forest carbon, and as forest carbon growth and yield default tables for the U.S. Department of Energy's Voluntary Reporting of Greenhouse Gases 1605(b) Program. Scientists also use these data to balance the carbon cycles, to validate models or other estimates, or to initiate models. Available forest carbon pools include above- and belowground live tree, dead wood, forest floor, and soil. The JAVA-based user interface is powerful and easy-to-use, and statistical analysis is based on R. A simplified version of COLE is also provided on the website that does not rely on JAVA for those users who have problems running a JAVA-based system on their computer.

[Poster PDF]

P-CA1.7

Spatial Biological and Industrial Carbon Budgets for Northern Wisconsin

Ahl, D. E., Department of Forest Ecology and Management, University of Wisconsin-Madison, deahl@wisc.edu

White, M. K., Department of Forest Ecology and Management, University of Wisconsin-Madison

Gower, S. T., Department of Forest Ecology and Management, University of Wisconsin-Madison

Bond-Lamberty, B., Department of Forest Ecology and Management, University of Wisconsin-Madison

Helmers, D., Department of Forest Ecology and Management, University of Wisconsin-Madison

Peckham, S., Department of Forest Ecology and Management, University of Wisconsin-Madison

We used satellite remote sensing data as inputs to a forest ecosystem process model that simulates carbon budgets and major carbon fluxes for a national forest, state forest, and non-industrial private forest in Wisconsin. Forest management practices were incorporated into the model to assess carbon cycling and sequestration at the landscape scale for future climate change scenarios. Output from the forest ecosystem process model was
compared to timber harvest data and input into a life cycle analysis of forest product chains to quantify sources of greenhouse gas emissions. Using
output from the ecosystem model and life cycle analysis, we discuss opportunities in forest management and forest product–related industrial sectors that can be modified to (i) increase carbon sequestration or (ii) mitigate greenhouse gas emissions.

[Poster PDF]

P-CA1.8

Carbon Sequestration Potential in New Mexico Rangelands

Jay Angerer, Texas A&M University, Dept. of Rangeland Ecology and Management, 2126 TAMU, College Station, TX, 77843-2126, jangerer@cnrit.tamu.edu

Joel Brown, USDA Natural Resources Conservation Service, Jornada Experimental Range, MSC, 3JER, PO Box 30003
New Mexico State University, Las Cruces, NM, 88003-0003, joelbrow@nmsu.edu

Robert Blaisdell, Texas A&M University, Dept. of Rangeland Ecology and Management, 2126 TAMU, College Station, TX, 77843-2126, blaisdel@cnrit.tamu.edu

Jerry Stuth, Texas A&M University, Dept. of Rangeland Ecology and Management, 2126 TAMU, College Station, TX, 77843-2126, jwstuth@cnrit.tamu.edu

The movement of carbon from the atmosphere and storage in the soil and vegetation (sequestration) is a contribution that agriculture and forestry can make to mitigate the greenhouse effect. Although the process of sequestration is relatively well understood by scientists and land managers, a systematic approach to prioritizing carbon sequestration activities is lacking, especially in the arid and semi-arid west. A regional characterization of carbon sequestration potential is needed so that government incentive programs can be targeted where impacts would be greatest. As part of the Southwest Regional Partnership on Carbon Sequestration, we identified target areas in New Mexico based on spatially explicit climate, soils and land tenure information organized in a GIS format. Once target areas were identified, we assessed baseline carbon for individual soils using COMET-VR, a CENTURY model-based interface to estimate change in soil carbon in response to management practices. COMET-VR was parameterized to predict carbon change under practices consistent with existing federal conservation programs used in New Mexico. Results indicated significant potential to increase carbon storage through changes in land use and management. Achieving that potential, however, is constrained by low rainfall and soil fertility. Broad, landscape scale analysis indicated much of the region would accumulate soil carbon at <0.1 t/ha/y unless changes in land use occur, primarily converting cropland to perennial cover. Land use conversion can result in accumulation rates of up to 1.0 t/ha/y in a limited portion of the state. Increasing soil carbon in the New Mexico will require policy and program decisions that motivate land managers to implement conservation practices on a broad scale.

[Poster PDF]

P-CA1.9

Summer and Winter Precipitation: Effects on Carbon Sequestration and Timber Production
under Current and Future Atmospheric CO 2

Ram Oren, Duke University, ramoren@duke.edu

Heather McCarthy, Duke University

Sari Palmroth, Duke University

Kurt Johnsen, USFS Southern Research Station

When properly and timely supplied by precipitation, water available to forests reduce the proportion of carbon cycling back to the atmosphere, locking higher proportion in a pool of carbon storage that is both relatively long lasting and profitable: the stems of trees. Improperly or untimely supplied, water limitation in summer or ice storms in winter reduce timber production and enhance carbon cycling. At the Duke Forest free-air CO₂ enrichment (FACE) site both drought and nutrient limitation force a larger proportion of carbon assimilated in photosynthesis to cycle back to the atmosphere within a year. Greater water availability and nutrients increased the production of wood and reduced the amount of carbon returning to the atmosphere by an equal quantity. Furthermore, more concentrated atmospheric CO₂ generated extra sugar, some used in wood production and some returned to the atmosphere through microbial respiration. Again, timely precipitation of appropriate quantity, and improved nutrition increased wood production at the expense of carbon cycling back to the atmosphere. Thus, conditions that promote timber production enhance carbon storage in both current and future atmospheric CO₂. Like hurricanes, ice storms are events that can quickly generate large amounts of biomass available for decomposition and cycling back to the atmosphere. In a single ice storm in southeastern U.S., generated in part by anomalously warm Atlantic sea surface temperatures, the loss of carbon was equivalent to 10% of the estimated annual sequestration in conterminous U.S. forests, amounting to about half a billion U.S. dollars in timber. Significantly, the loss in the elevated CO₂ plots was only one third that in the surrounding forest. Thus, future carbon sequestration and timber production will greatly depend on the manifestation of climate change in the temporal dynamics and quantities of precipitation, although elevated atmospheric CO₂ may confer some protection against adverse changes in precipitation, somewhat diminishing the projected negative effects of increased atmospheric CO₂ on climate.

We study the effects of climate variability and change on forest resources at scales ranging up to regions. Our results are relevant to makers of policies aimed at managing water, carbon and timber resources, as well as with organizations concerned with biodiversity and vegetation-ecosystem dynamics. The information we provide is relevant to current issues of water availability, carbon sequestration and timber production, but it is unique in that it predicts the response of an important and widely planted timber species (loblolly pine) to future atmospheric CO₂ under naturally varying climate.