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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Interspecific variation in leaf-level biogenic emissions of the Bambuseae

Melnychenko, Andrea Natalie 28 June 2013 (has links)
Plants emit a diverse range of biogenic volatile organic compounds (BVOCs) into the atmosphere, of which isoprene is the most abundantly emitted. Isoprene significantly affects biological and atmospheric processes, but the range of isoprene and BVOCs present in bamboos has not been well characterized. In this thesis I explore the range of isoprene emission found in bamboos and relate it to plant morphological and physiological characteristics. In addition, I measure and relate the entire suite of BVOCs present in the bamboos to their fundamental isoprene emission rate. Interspecific variation in isoprene emission documented in a comprehensive survey of bamboos. Two groups of bamboo species were measured in the greenhouse and the field. Elevated photosynthetic rate was significantly correlated with isoprene emission. In the field, dark respiration rate was highest in bamboos that made the least amount of isoprene. The total BVOC suite was significantly influenced by whether or not leaf-level isoprene emission was present. I conclude that bamboos vary with regard to physiology, morphology, and total BVOC suite and that isoprene emission is correlated with these changes, and introduce the bamboos as a novel system for studying the impacts of isoprene emission.
2

Agricultural Management Decisions Impact Isoprene Emission and Physiology of Arundo donax, an Emerging Bioenergy Crop

Maxfield, Jason Charles 28 March 2014 (has links)
Arundo donax (Giant Reed) is quickly being developed as a rapidly-growing, robust, and highly productive bioenergy crop, with large scale cultivation of this species planned for the Columbia River basin of the Pacific Northwest (USA). Despite its potential as a next generation biomass crop, relatively few studies have examined the physiological performance of A. donax under agricultural conditions. Unlike traditional crops, A. donax is known to be a high-emitter of the volatile compound isoprene, which may significantly impact regional air quality, but it has not been widely cultivated in North America and little is known about how this species will perform in the Pacific Northwest. Over two field seasons, we measured isoprene fluxes from A. donax plants in both greenhouse conditions and in an agricultural field setting under a variety of conditions and fertilizer treatments. We also measured several other attributes of A. donax productivity and leaf physiology including chlorophyll content, photosynthesis rate, stomatal conductance, specific leaf mass, water use efficiency and gas exchange. We found that A. donax physiologically performs well under cultivation in the Columbia River basin, but that it also emits isoprene at significantly higher rates than previous reports indicate. We also found that both isoprene emission and leaf physiology were highly affected by agricultural management decisions, including nitrogen and irrigation management. Our findings indicate that crop management strategies can be developed that simultaneously seek to minimize isoprene emission while maximizing biomass production in this newly emerging bioenergy crop.

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