J. M. Kimble

The potential of U.S. cropland to sequester carbon and mitigate the greenhouse effect

Objectives Basic Processes The Greenhouse Process Global Trends in Greenhouse Gas Emissions The Role of Agriculture in U.S. Emissions of Three GHGs The SOC Pool in U.S. Soils and SOC Loss from Cultivation Processes in Governing Emissions from the Pedosphere Plant Action Soil Processes Soil Quality Strategies for Mitigating Emissions from Cropland U.S. Cropland Sustainable Management Studies Soil Erosion Management Land Conversion and Restoration Conversion of Marginal Land Restoration of Degraded Soils Biofuels for Offsetting Fossil Fuel Intensification of Prime Agricultural Land Conservation Tillage and Residue Management Irrigation Water Management Improved Cropping Systems The Carbon Sequestration Potential of Arable Land U.S. Croplands Overall Potential to Mitigate the Greenhouse Effect Techniques for Sequestration Rates of SOC Sequestration Possible Implementation Obstacles Required Action Conclusions - The Win-Win Strategy Agricultural Profits from Environmental Improvements SOCs Monetary Value SOCs Environmental Value Global Potential Appendix 1: Definitions Appendix 2: Researchable Topics

The potential of U.S. forest soils to sequester carbon and mitigate the greenhouse effect.

THE EXTENT, GENERAL CHARACTERISTICS, AND CARBON DYNAMICS OF U.S. FOREST SOILS Introduction and General Description of US Forests, J.M. Kimble, R.A. Birdsey, R. Lal, and L.S. Heath Current and Historical Trends in use, Management and Disturbance of United States Forest Lands, R.A. Birdsey and G.M. Lewis Carbon Trends in US Forest Lands: A Context for the Role of Soils in Forest Carbon Sequestration, L.S. Heath, J.E. Smith and R.A. Birdsey Quantifying the Organic Carbon Held in Forested Soils of the United States and Puerto Rico, M. Johnson and J. Kern Techniques to Measure and Strategies to Monitor Forest Soil Carbon, C. Palmer SOILS PROCESSES AND CARBON DYNAMICS Carbon Cycling in Forest Ecosystems with an Emphasis on Belowground Processes, K.S. Pregitzer Forest Soil Ecology and Soil Organic Carbon, S.J. Morris and E.A. Paul Global Change and Forest Soils, J. Hom Processes Affecting Carbon Storage in the Forest Floor and in Downed Woody Debris, W.S. Currie, R.D. Yanai, K.B. Piatek, C.E. Prescott, and C.L. Goodale Impacts of Natural Disturbance on Soil Carbon Dynamics in Forest Ecosystems, S.T. Overby, S.C. Hart, and D.G. Neary MANAGEMENT IMPACTS ON US FOREST SOILS Soil Erosion in Forest Ecosystems and Carbon Dynamics, W.J. Elliot Impact of Soil Restoration, Management, and Land Use History on Forest Soil Carbon, W. M. Post Fire and Fire Suppression Impacts on Forest Soil Carbon D. Page-Dumroese, M. Jurgensen and A. Harvey Soil Carbon Sequestration and Forest Management: Challenges and Opportunities, C.M. Hoover Management Impacts on Compaction in Forest Soils, R. Lal SPECIFIC FOREST ECOSYSTEMS Soil Carbon in Permafrost Dominated Boreal Forests, J. Hom Soil Carbon Distribution in High-Elevation Forests of the U.S.A., J.G. Bockheim Soil Carbon in Arid and Semiarid Forest Ecosystems, D.G. Neary, S.T. Overby and S.C. Hart Carbon Cycling in Wetland Forest Soils, C. Trettin and M.F. Jurgensen Carbon Storage in North American Agroforestry Systems, P.K. Nair and V.D. Nair Soil Carbon in Urban Forest Ecosystems, R. Pouyat, J. Russell-Anelli, I. Yesilonis, and P.M. Groffman Soil Organic Carbon in Tropical Forests of the United States of America, W.L. Silver, A.E. Lugo, and D. Farmer SYNTHESIS AND POLICY IMPLICATIONS The Potential of U.S. Forest Soils to Sequester Carbon, L.S. Heath, J.M. Kimble, R.A. Birdsey, and R. Lal Economic Analysis of Soil Carbon in Afforestation and Forest Management Decisions, B. Sohngen, R. Alig, and Suk-won Choi Research and Development Priorities for Carbon Sequestration in Forest Soils, R. Lal

Effects of hydrocarbon spills on the temperature and moisture regimes of Cryosols in the Ross Sea region

Hydrocarbon spills have occurred on Antarctic soils where fuel oils are utilized, moved or stored. We investigated the effects of hydrocarbon spills on soil temperature and moisture regimes by comparing the properties of existing oil contaminated sites with those of nearby, uncontaminated, control sites at Scott Base, the old Marble Point camp, and Bull Pass in the Wright Valley. Hydrocarbon levels were elevated in fuel-contaminated samples. Climate stations were installed at all three locations in both contaminated and control sites. In summer at Scott Base and Marble Point the mean weekly maximum near surface (2 cm and 5 cm depth) soil temperatures were warmer (P<0.05), sometimes by more than 10°C, at the contaminated site than the control sites. At Bull Pass there were no statistically significant differences in near-surface soil temperatures between contaminated and control soils. At the Scott Base and Marble Point sites soil albedo was lower, and hydrophobicity was higher, in the contaminated soils than the controls. The higher temperatures at the Scott Base and Marble Point hydrocarbon contaminated sites are attributed to the decreased surface albedo due to soil surface darkening by hydrocarbons. There were no noteworthy differences in moisture retention between contaminated and control sites.