Forest soils contribute to a significant portion of the world's carbon flux due to both natural and anthropogenic changes. In terms of human management of carbon pools, forest soil organic matter (SOM) is important because it potentially stores carbon more permanently than living vegetation. Yet, this potential is poorly understood or managed for because of the difficulty in measuring changes in SOM pools over time and space. Modeling combined with intensive field sampling can help overcome these limitations because it extracts from empirically observed relationships to account for the components of SOM formation (topography, time, parent material, organisms and climate [fns2] ). This study utilizes intensive field data, statistical models and process-based ecosystem models to investigate the spatial distribution and dynamics of soil organic carbon dynamics in two contrasting ecosystems--the northern hardwood forest in the Green Mountains, VT and the tabonuco forest in the Luquillo Experimental Forest, PR. In both forests landscape position emerged as the dominate factor in explaining SOM distribution. In Vermont, additional variation was explained by aspect and slope and in Puerto Rico additional variation was explained by landscape factors interrelated to soil drainage. Process-based modeling proved to be a useful management and experimental tool in cases were empirical approaches were impractical for both forests. In Vermont, three ecosystem models demonstrated a substantial reduction of soil organic carbon and harvestable biomass due to the removal of woody carbon by logging after 240 years of rotations. In Puerto Rico, the Century model showed that changes in litter quality and quantity were not likely responsible in explaining landscape level SOM differences. Overall, well drained soils located in colder climates stored the highest SOM whereas poorly drained and highly disturbed soils in steep humid climates stored the lowest SOM. This research demonstrates that although SOM amounts are highly variable over many spatial and temporal scales, intuitive relationships are borne out with modeling tools and by careful investigation of the five soil forming factors. Results also raise questions about how these ecosystems and their SOM pools may change in response to changing climate conditions of the future.

Significant differences were found to exist among various LC/LU's in regards to mean SOC stocks (kg m−2, 0-20cm), with the highest amounts found in Cypress Swamp (9.7), Hardwood Swamp (9.6) and Mixed Wetland Forest (7.8). Additionally, significant SOC stock differences among various soil types exist as well, with the highest mean stocks (kg m−2, 0-20cm) belonging to Saprists (12), Aquolls (9.8) and Aquepts (9.4). Geostatistical (kriging) models developed for the study area show approximately 102 - 108 Tg SOC (kg C m−2) are held within the upper 20cm of soils representing historical conditions (DS1) and 211 - 320 Tg SOC (kg C m−2) are held within the upper 20cm of soils representing current conditions (DS2), which suggests the soils in the study area have been a net sink for C during the last 40 years. Highest SOC stock sequestration rates were observed in Hardwood/Cypress Swamp (51 g C m−2 yr−1) and the lowest observed in Xeric Upland Forest ( -129 g C m−2 yr−1). Additionally, site remaining in Row/field Crop lost SOC ( -2g C m−2 yr−1) on average. Interestingly, three out of four classes switching to Urban resulted in net gains of SOC stocks. Geostatistical models improved the knowledge of the spatial distribution and variability of SOC in the study area with implications for SOC cycling, land management, environmental conservation and policy decisions.

Results showed that five sites had different spatial structure - Hardwood Hammock and Forest and Improved Pasture demonstrated both large variation at both coarse scale (67 and> 200 m) and very fine scale (2 m). Sandhill, Pineland and Dry Prairie were dominated by variation at very fine scales (2 and 7 m). All the five sites showed large variability at very fine scales, indicating the close coupling of SOC variation to structure and composition of vegetation. Lastly, the SOC change coupled with LULC and climatic factors over the past four decades was studied. Significant SOC accumulation was observed between 1965-1996 and 2008-2009 and concomitant LULC and LULC change significantly affected SOC change, less so climatic factors. The study improved the knowledge of the spatial and temporal variation of SOC in the complex soil-landscape continuum of Florida with implications for carbon cycling and sequestration, land resource management, and ecosystem service assessment.

Biofuel Crop Sustainability brings together the basic principles of agricultural sustainability and special stipulations for biofuels, from the economic and ecological opportunities and challenges of sustainable biofuel crop production to the unique characteristics of particular crops which make them ideal for biofuel applications. This book will be a valuable resource for researchers and professionals involved in biofuels development and production as well as agriculture industry personnel. Chapters focus the broad principles of resource management for ecological, environmental and societal welfare, the sustainability issues pertaining to several broad categories of biofuel crops , as well as the economics and profitability of biofuels on both a local and international scale. Coverage includes topics such as utilizing waste water for field crop irrigation and algae production, reliability of feedstock supply, marginal lands, and identifying crops with traits of significance for survival and growth on low fertility soils. The development of production practices with low external inputs of fertilizer, irrigation, and pesticides is also covered. Biofuel Crop Sustainability will be a valuable, up-to-date reference for all those involved in the rapidly expanding biofuels industry and sustainable agriculture research fields.

The Soil Organic Carbon Mapping cookbook provides a step-by-step guidance for developing 1 km grids for soil carbon stocks. It includes the preparation of local soil data, the compilation and pre-processing of ancillary spatial data sets, upscaling methodologies, and uncertainty assessments. Guidance is mainly specific to soil carbon data, but also contains many generic sections on soil grid development, as it is relevant for other soil properties. This second edition of the cookbook provides generic methodologies and technical steps to produce SOC maps and has been updated with knowledge and practical experiences gained during the implementation process of GSOCmap V1.0 throughout 2017. Guidance is mainly specific to SOC data, but as this cookbook contains generic sections on soil grid development it can be applicable to map various soil properties.

According to the original proposal the objective was to simulate the spatial distribution of land-use change and carbon exchange for the entire tropics from roughly 1880 to the present. The final product of the entire project was to be both a new, spatially-explicit dataset of carbon release for the entire tropics, and an analysis of the effect of incorporating this dataset into the GISS (Goddard Institute for Space Studies) AGCM (atmospheric general circulation model). Here at SUNY ESF, the assignment was to develop models to simulate the distribution of land use over time. These models would then be combined with carbon balance models which had been used in most of the earlier publications on this subject. Together, these two types of models were to be used to synthesize the spatial and temporal patterns of carbon release by deforestation for the entire tropics. This was an extraordinarily comprehensive, programming-intensive, data-extensive, and indeed daunting project, as both the programming and deriving the basic data for all tropical continents were extremely difficult. This document summarizes the products and conclusions of the research program.