Impacts of Pollution Control, Ecosystem Conservation, and Infrastructure on the Agriculture-Land-Environment Nexus
Creators: name: Wang, Zhan
Publisher: name: Purdue University Graduate School
Year: 2023
Subjects: Agricultural spatial analysis and modelling
Environmental management
Agricultural economics
Environment and resource economics

description: A major challenge of achieving sustainable development is to balance two critical targets with finite resources: to secure food security for a growing population with rising consumption demands, and to prevent further pollution into the environment and losses in ecosystem services. More importantly, the targets of food production and environment protection are not only related to socio-economic and technological development, but also tangled together both ecologically and economically, in particular regarding competition for land – the necessary natural resource for achieving both targets. In view of this, a comprehensive understanding about how to achieve sustainable development requires integrated analyses of the nexus of agricultural production, land use and environmental protection (the “agriculture-land-environment nexus”), interactions between these components, and their responses to socio-economic development and policies. <br> This dissertation consists of three essays focusing on the impacts of environmental protection polices and infrastructure on the agriculture-land-environment nexus. The first essay analyzes how pollution reduction influences ecosystem services, with both a theoretical model and also empirical analysis with city-level data from China. Existing literature from the environmental and ecological fields reports that pollution reduction contributes to ecosystem services, but the ecosystem effects via economic channels remain under-addressed. We find when integrated together with an economic system, the reduction of pollution causes losses in the area of natural land that supports ecosystem services, which is further supported by empirical evidence. This finding emphasizes the importance of taking ecosystem effects into account on the design, implementation and evaluation of pollution control policies. <br> The second essay researches the impact of a large-scale forestry and grassland conservation policy in China, the grain-to-green project (GTGP), on cropland supply and crop production. In this essay, we first develop a theoretical model of the relationships between cropland supply, land value (with market access as proxy) and GTGP, and then empirically test these relationships using gridded data from China. We find GTGP not only directly reduces cropland area, but also restricts the elasticity of cropland supply in response to market access. Furthermore, we apply the GTGP’s impacts on cropland supply elasticity on a grid-solving computable model, in order to both validate the model and elasticity estimates via hindcasting and evaluate the GTGP’s impact on agricultural production via simulation. In the computable model where all grids are connected with crop markets, we find two effects of GTGP on agriculture: the direct effect that restricts cropland use and crop production in regions where it is implemented, and the indirect effect that increases crop production on regions not restricted or less restricted by GTGP. Essay 2 contributes to the literature by not only estimating the pattern of gridded cropland supply in China, but also reveals the indirect effect of GTGP on agriculture, which has seldom been researched. <br> The third essay researches the impact of transportation infrastructure on Brazilian agriculture, land use, and greenhouse gas (GHG) emissions. Combining a geographic information system (GIS) based analysis and computable model simulation, we find the expansion of infrastructure mainly contributes to the transportation cost reduction in inland Brazil and causes local cropland expansion and increased GHG emissions from land conversion. However, the shifting of crop production towards inland Brazil reduces the demand for cropland in southeastern and southern Brazil, which offsets the impact on cropland expansion and GHG emissions at the national level. Findings in Essay 3 indicate the importance of capturing both spatial heterogeneity and spatial spillover effects of infrastructure expansion when evaluating agricultural and environmental impacts.