Understanding Land Use and Land Cover Change: National Forest Dynamics and Regional Willow Crop Environmental Impacts Based on Spatial Modeling and Spatial Life Cycle Assessmen

Land use and land cover change (LULCC) is a critical area of scientific research that contributes to the understanding of fundamental socioeconomic, environmental, and geographical processes and applications. This dissertation focused on three aspects of LULCC, namely i) understanding spatial patterns and process of LULCC related to forest cover changes, ii) socioeconomic and proximate factors related to forest cover losses, and iii) carbon emission and energy balance of LULCC related to bioenergy cropping. More specifically: 1) Spatial patterns of forest cover changes were quantified using a novel spatial metric, forest attrition distance. The metric correlates with spatial patterns of forest cover changes and is effective in identifying forest attrition. It was applied across the conterminous U.S. and showed disproportionately large forest attrition in western U.S., rural areas, and public lands. 2) Gross forest cover losses in U.S. counties in 1990s and 2000s were found to be significantly related to seven predictors variables of underlying and proximate factors. Among these factors, slope and agriculture are more influential than others such as education, urbanization, and population changes. Spatial error model regression was applied to address spatial autocorrelation, and model fit expressed through coefficient of determination R2 reached 0.60 in the 1990s and 0.82 in the 2000s. The increasing magnitude of slope and agriculture coefficients from 1990s to 2000s indicate higher pressure on forest losses from harvesting and lower pressure from croplands. 3) Conversion of grasslands and croplands to shrub willow crops was investigated in spatial life cycle assessment (LCA) and initial land use had an impact on GHG emissions. The life cycle GHG emissions for willow grown on cropland averaged -126.8 kg CO 2eq per Mg biomass and for grassland were 27.7 kg CO2eq per Mg biomass. Results showed substantial potential of reducing carbon emission in the region by shrub willow cultivations as well as large potential of producing energy efficiently.