Persistent Link:
http://hdl.handle.net/10150/194012
Title:
Riparian Dynamics: The Ebb and Flow of Ecological Function
Author:
McCoy, Amy LaFerne
Issue Date:
2009
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Competition over freshwater resources is increasing at local and global scales. Growing urban and suburban centers utilize surface and groundwater resources to meet municipal, industrial, and agricultural demands, often at the expense of riparian ecosystems. Paradoxically, those same urban centers produce a significant volume of treated effluent that can be reused to restore and sustain riparian systems. Use of effluent as a source of water for the environment raises important questions about the benefits and impacts of effluent on riparian functions and ecosystem services, particularly in the context of climate change and drought conditions. This dissertation addresses knowledge gaps surrounding riparian change and resilience along the effluent-dominated Upper Santa Cruz River in southern Arizona. Appendix A investigates whether the Netleaf hackberry (Celtis laevigata var. reticulata) tree can provide accurate information on historic changes in climatic and hydrological conditions. Results indicate that hackberry trees do record climate-related stress in annual ring-width patterns and can therefore provide a historic frame of reference against which to compare current and future changes in riparian conditions. Appendix B documents spatial and temporal patterns of effluent uptake by Fremont cottonwood trees (Populus fremontii) through development of a new application for dendrochronology, specifically dendrochemistry. Results show that annual tree rings contain temporally variable concentrations of a micropollutant found only in effluent and may have the potential to record spatial and temporal patterns of effluent dispersion in riparian ecosystems. Appendix C investigates the complex interactions of ecohydrological conditions that led to a riparian mortality event along the Upper Santa Cruz River in 2005. Effluent is shown to contribute to riparian vegetation expansion, but also, due to its consistent delivery of nutrients and water, homogenize the system and ultimately diminish its resilience to perturbations and stress. Results highlight the paradoxical nature of effluent as both a contributor to riparian growth and a potential impediment to riparian function. This paradox can be resolved through a well-defined effluent impact monitoring and assessment program that incorporates historic information as well as current trends to detect significant changes in ecosystem functions and services.
Type:
text; Electronic Dissertation
Keywords:
Dendrochronology; Ecological monitoring; Ecosystem Services; Effluent; Gadolinium; Riparian Ecosystems
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Arid Lands Resource Sciences; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Orr, Barron J.
Committee Chair:
Orr, Barron J.

Full metadata record

DC FieldValue Language
dc.language.isoENen_US
dc.titleRiparian Dynamics: The Ebb and Flow of Ecological Functionen_US
dc.creatorMcCoy, Amy LaFerneen_US
dc.contributor.authorMcCoy, Amy LaFerneen_US
dc.date.issued2009en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractCompetition over freshwater resources is increasing at local and global scales. Growing urban and suburban centers utilize surface and groundwater resources to meet municipal, industrial, and agricultural demands, often at the expense of riparian ecosystems. Paradoxically, those same urban centers produce a significant volume of treated effluent that can be reused to restore and sustain riparian systems. Use of effluent as a source of water for the environment raises important questions about the benefits and impacts of effluent on riparian functions and ecosystem services, particularly in the context of climate change and drought conditions. This dissertation addresses knowledge gaps surrounding riparian change and resilience along the effluent-dominated Upper Santa Cruz River in southern Arizona. Appendix A investigates whether the Netleaf hackberry (Celtis laevigata var. reticulata) tree can provide accurate information on historic changes in climatic and hydrological conditions. Results indicate that hackberry trees do record climate-related stress in annual ring-width patterns and can therefore provide a historic frame of reference against which to compare current and future changes in riparian conditions. Appendix B documents spatial and temporal patterns of effluent uptake by Fremont cottonwood trees (Populus fremontii) through development of a new application for dendrochronology, specifically dendrochemistry. Results show that annual tree rings contain temporally variable concentrations of a micropollutant found only in effluent and may have the potential to record spatial and temporal patterns of effluent dispersion in riparian ecosystems. Appendix C investigates the complex interactions of ecohydrological conditions that led to a riparian mortality event along the Upper Santa Cruz River in 2005. Effluent is shown to contribute to riparian vegetation expansion, but also, due to its consistent delivery of nutrients and water, homogenize the system and ultimately diminish its resilience to perturbations and stress. Results highlight the paradoxical nature of effluent as both a contributor to riparian growth and a potential impediment to riparian function. This paradox can be resolved through a well-defined effluent impact monitoring and assessment program that incorporates historic information as well as current trends to detect significant changes in ecosystem functions and services.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectDendrochronologyen_US
dc.subjectEcological monitoringen_US
dc.subjectEcosystem Servicesen_US
dc.subjectEffluenten_US
dc.subjectGadoliniumen_US
dc.subjectRiparian Ecosystemsen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineArid Lands Resource Sciencesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorOrr, Barron J.en_US
dc.contributor.chairOrr, Barron J.en_US
dc.contributor.committeememberMarsh, Stuart E.en_US
dc.contributor.committeememberMeko, David M.en_US
dc.contributor.committeememberSheppard, Paul R.en_US
dc.contributor.committeemembervan Leeuwen, Willem J.D.en_US
dc.identifier.proquest10732en_US
dc.identifier.oclc659753543en_US
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