1. Project 2: Geospatial and Statistical Basis for Mine Soil Sampling for C Sequestration Accounting. Objectives: To determine the horizontal and vertical distribution and variability of sequestered C in mine soils. To determine the MCD and MDD of SOC on mined land for carbon accreditation analysis. Methods: Determined the horizontal and vertical distributions of SOC (Mg ha -1 ) to estimate the profit-to-cost ratio $(SOC Credits ) / $(SOC Inventory ), based on the market price of C and the costs of C inventorying. Project 3: Carbon Sequestration Empirical Models for Forests and Soils on Mined Land in the Eastern U.S. Coalfields. Objectives: To estimate and compare the Eco_C content sequestered on disturbed and undisturbed forest land. To determine the effects of mine soil quality and stand age on the C sequestration potential of forested mined land. Methods: Analyzed C data from 14 mined and 8 non-mined forests in seven states. Results and Inferences:  The Eco_C in forest stands on mined land was in the decreasing order pine (148 Mg ha -1 ) > hardwood (130 Mg ha -1 ) > mixed (118 Mg ha -1 ), where 75% was in the total tree biomass (stem, roots, branches).  The tree and litter carbon pools were similar on mined and non-mined hardwood stands across the entire range of site quality. However, mined land SOC levels were lower than average natural sites. (Fig. 2) Beyhan Y. Amichev Ph. D. Candidate Department of Forestry (bamichev@vt.edu) Introduction Main objective: To develop a decision support tool for predicting carbon sequestration by forests and soils on coal-mined land in the Appalachians. Hypothesis: New managed forests on mined land sequester carbon at significantly higher rates than mined lands sown to grasses and abandoned. James A. Burger Professor of Forestry and Soil Science Department of Forestry (jaburger@vt.edu) Conclusions and Implications  Reforestation on mined land establishes a long-term sink for atmospheric carbon which is stored in the soil and litter and is locked in tree biomass and wood products.  Site quality has an exponential effect on Eco_C sequestration in both pine and mixed stands and the models showed Eco_C decrease with stand age due to natural pine tree deterioration in older pine stands and in the pine component of mixed stands. Eco_C increased asymptotically with stand age in hardwood stands but was not affected by site quality.  The results indicated that pre-law (pre-1977) surface coal mining procedures used in the Eastern U.S. could degrade forest site quality and could jeopardize the long- term productivity and C sequestration potential of forested mined lands.  The proposed DSS tool will be suitable for use by private landowners, regional planners, and politicians in managing reclaimed mined lands. It will help guide reclamation practices on thousands of hectares of mined land with the goal of increasing forest productivity and carbon sequestration. Four individual projects contributed specific parts needed to test the hypothesis. In Project 1, we developed a new laboratory procedure for soil organic carbon (SOC) measurement that differentiated between plant- sequestered and coal-derived carbon in mine soils. In Project 2, we used SOC data from selected mined study sites to develop a field measurement protocol for SOC estimation on mined land, including the vertical and horizontal accuracy and precision of SOC inventorying, the maximum cost-effective depth (MCD) and the minimum detectable difference (MDD) of SOC measurements between two successive carbon inventories. In Project 3, we developed empirical models for ecosystem carbon sequestration by reclaimed forests as a function of mine soil quality and stand age. In Project 4, we used the results and inferences from Projects 2 and 3 to design and develop a DSS tool to estimate the ecosystem carbon (Eco_C) content sequestered by forests established by a combination of treatments of different intensity for three commonly- used forest species groups, and the carbon stock in wood products from harvested biomass obtained from these forests. Project 1: Soil Organic Carbon Measurement Procedure for Mine Soils. Objectives: To design a new technique for mine soil C measurement that will differentiate between pedogenic (organic matter) and geogenic (coal) C forms present in mine soils. To evaluate and compare the performance of the new C measurement method and the Walkley-Black (WB) procedure, a wet oxidation technique) for soil organic carbon (SOC) analysis on mine soils. Methods: The 16-step procedure: combination of a chemical treatment to remove carbonates, a thermal treatment at 375 o C to remove pedogenic organic matter, and an elemental C analysis at 900 o C. Determined correction factors for the loss of volatile C forms from coal and soil organic matter during the thermal treatment. Tested the 16-step and the WB procedures on mine soil mixtures of homogeneous coal content; percent relative uncertainty from the mean (PRUM, %) was computed as Results and Inferences:  The 16-step method yielded better results than the WB procedure for mine spoil materials that are most commonly used for mined land reclamation in the Eastern U.S. coalfields, i.e., weathered SS and SiS.  Coal fragments in mine soils lead to SOC overestimation when measured by the WB method; 55% of the variation in SOC was due to the oxidation of carbon from coal fragments in the soil.  Developed a regression model (R 2 =55%) for coal correction of SOC measurements obtained by the WB procedure (WB–SOC, wt%): where SOC (wt%) = true soil organic carbon content expressed as percent by sample weight; Order =1 for SS, =2 for SiS, and =3 for 50/50 SS/SiS material. Table 1. Evaluation results for the 16-step and WB methods used in Project 1. Estimated MCD as the soil depth at which the profit-to-cost ratio becomes less than 1, i.e. we lose money. Estimated MDD as SOC(Mg ha -1 ) future – SOC(Mg ha -1 ) present, measured at a future C inventory event, so that the difference is statistically significant at a chosen confidence level, e.g. 95%. Results and Inferences: Figure 1. Field measurement protocol for SOC estimation on mined land. Acknowledgements We thank the U.S. Department of Energy (DE-FG26-02NT41619), the Powell River Project, and Office of Surface Mining / Virginia Department of Mines, Minerals, and Energy for funding this research. Figure 2. Empirical models for Eco_C sequestration on forested mined land. Project 4 (in progress) : DSS Based on Expert Knowledge for Predicting Carbon Sequestration for Forest Establishment Practices on Mined Land. Objective: To build the framework of a decision support tool consisting of the first iteration of a dynamic simulation model to predict carbon sequestration for nine reforestation scenarios on mined land: 3 forest types (white pine, hybrid poplar, and native hardwoods) by forest establishment practices of 3 levels of intensity using weed control, soil tillage, and fertilization. Methods: Modeled the C sequestration in wood products in-use and in-landfills: Used the results and inferences from Projects 2 and 3 to model C sequestration in tree biomass, soils (accounting for the MCD), roots, and litter layer as a function of site quality and stand age:  SOC concentration ranged from 0.14 to 1.02 wt%, and coal C concentration ranged from 0.00 to 2.80 wt% among all soil samples in obtained from Ohio, West Virginia, and Virginia.  The surface SOC content, 0-10cm, was spatially dependant up to 575 m for the mined sites in Ohio, and up to 590 m in West Virginia.  The results indicated that mined sites older than 9-years of age should be selected for C sequestration projects, due to the inherent variation of soil carbon in mine soils.