Dissertation/Thesis Abstract

Land use and disturbance interactions in dynamic arid systems: Multiscale remote sensing approaches for monitoring and analyzing riparian vegetation change
by Villarreal, Miguel L., Ph.D., The University of Arizona, 2009, 167; 3366717
Abstract (Summary)

Riparian systems are comprised of interacting aquatic and terrestrial elements that contribute distinctively to the natural capital of arid landscapes. Riparian vegetation is a major component of riparian systems, providing the ecosystem services required to support watershed health. The spatial and temporal distributions of riparian vegetation are influenced by hydrologic and disturbance processes operating at scales from local to regional. I believe both these processes are well suited to monitoring using synoptic and multitemporal approaches.

The research in this dissertation is presented as 3 related studies. The first study focused on historical riparian dynamics related to natural disturbance and land use. Using current and historical riparian vegetation maps, we examined vegetation change within catchments of varying land use intensity. Results suggest that land use activities and wastewater subsidy affect the rate of development and diversity of riparian community types.

The second study used moderate resolution satellite imagery to monitor changes in riparian structure and pattern within a land cover change framework. We classified Landsat Thematic Mapper satellite imagery of the Upper Santa Cruz River watershed using Classification and Regression Tree (CART) models. We tested the ability of our models to capture change at landscape, floodplain, and catchment scales, centering our change detection efforts on a riparian tree die-off episode and found they can be used to describe both general landscape dynamics and disturbance-related riparian change.

The third study examined historical and environmental factors contributing to spatial patterns of vegetation following two riparian tree die-offs. We used high resolution aerial imagery to map locations of individual live and dead trees and collected a suite of environmental variables and historical variables related directly and indirectly to land use and disturbance history. We tested for differences between groups of live and dead trees using Multi-response Permutation Procedures and found strong relationships between historical factors and mortality incidence.

The results from these studies demonstrate the importance of examining historical information and spatial linkages across scales when monitoring riparian vegetation. From a land management perspective, the results identify the need for landscape-level, ecosystem-based management programs to maintain functioning and spatially connected riparian systems.

Indexing (document details)
Advisor: Yool, Stephen R.
Commitee: Hutchinson, Charles F., Marsh, Stuart E., van Leeuwen, Willem J.D.
School: The University of Arizona
Department: Geography
School Location: United States -- Arizona
Source: DAI-B 70/07, Dissertation Abstracts International
Subjects: Ecology, Physical geography, Remote sensing
Keywords: Disturbance, Land cover change, Land use, Landscape ecology, Remote sensing, Riparian vegetation, Spatial analysis
Publication Number: 3366717
ISBN: 9781109284027
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