Electronic Theses and Dissertations

Identifier

730

Date

2012

Date of Award

11-27-2012

Document Type

Dissertation

Degree Name

Doctor of Philosophy

Major

Earth Sciences

Committee Chair

Hsiang-te Kung

Committee Member

Daniel Larsen

Committee Member

Takuya Nakazato

Committee Member

Angela Antipova

Abstract

Switchgrass (Panicum virgatum L.) is a perennial plant species native to the United States that is capable of adapting to a wide variety of geographic and climate conditions. There are two ecotypes of switchgrass: lowland varieties which favor areas with higher rainfall and longer growing seasons and upland varieties which favor areas with cooler and drier climate conditions with shorter growing seasons. Switchgrass has the capacity to become a significant bioenergy feedstock for lignocellulosic ethanol conversion. The purpose of this dissertation is to determine which regions in China are suitable for switchgrass production, estimate potential biomass yield, and examine the effects of predicted climate change scenarios at the end of the 21st century on potential yields in China. To accomplish these goals, two ecological niche models (Maxent and GARP) are implemented based on known switchgrass presence data throughout the United States to ascertain which regions in China have suitable habitats for its growth. Multiple linear regression analysis was performed on a comprehensive database of 1,190 switchgrass field trials in 39 separate locations across the United States to build a model that estimates potential switchgrass yields across China. Future climate projections (2070 – 2099) from the Hadley Centre Coupled Model, version 3 (HadCM3) global circulation model (GCM) are employed in the multiple linear regression model to make switchgrass yield estimations for the end of the century. The ecological niche modeling results reveal China has large areas of suitable habitat for switchgrass development. The multiple linear regression analysis demonstrates that China has the potential to produce large quantities of switchgrass, even more so than in the United States; however, analysis of the impact of climate change by the end of the 21st Century indicates that warmer temperatures will result in lower yields on average, a substantial reduction in suitable habitat for lowlands, and an expanded habitat range for upland ecotypes. This dissertation concludes that switchgrass should be considered a viable plant species to serve as a bioenergy feedstock for lignocellulosic ethanol production in China, and the results herein offer guidelines regarding optimal regions in the country for switchgrass production.

Comments

Data is provided by the student.

Library Comment

dissertation or thesis originally submitted to the local University of Memphis Electronic Theses & dissertation (ETD) Repository.

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