Cordilleran Forest Scaling Dynamics And Disturbance Regimes Quantified By Aerial LiDAR

Persistent Link:
http://hdl.handle.net/10150/311231
Title:
Cordilleran Forest Scaling Dynamics And Disturbance Regimes Quantified By Aerial LiDAR
Author:
Swetnam, Tyson Lee
Issue Date:
2013
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:
Semi-arid forests are in a period of rapid transition as a result of unprecedented landscape scale fires, insect outbreaks, drought, and anthropogenic land use practices. Understanding how historically episodic disturbances led to coherent forest structural and spatial patterns that promoted resilience and resistance is a critical part of addressing change. Here my coauthors and I apply metabolic scaling theory (MST) to examine scaling behavior and structural patterns of semi-arid conifer forests in Arizona and New Mexico. We conceptualize a linkage to mechanistic drivers of forest assembly that incorporates the effects of low-intensity disturbance, and physiologic and resource limitations as an extension of MST. We use both aerial LiDAR data and field observations to quantify changes in forest structure from the sub-meter to landscape scales. We found: (1) semi-arid forest structure exhibits MST-predicted behaviors regardless of disturbance and that MST can help to quantitatively measure the level of disturbance intensity in a forest, (2) the application of a power law to a forest overstory frequency distribution can help predict understory presence/absence, (3) local indicators of spatial association can help to define first order effects (e.g. topographic changes) and map where recent disturbances (e.g. logging and fire) have altered forest structure. Lastly, we produced a comprehensive set of above-ground biomass and carbon models for five distinct forest types and ten common species of the southwestern US that are meant for use in aerial LiDAR forest inventory projects. This dissertation presents both a conceptual framework and applications for investigating local scales (stands of trees) up to entire ecosystems for diagnosis of current carbon balances, levels of departure from historical norms, and ecological stability. These tools and models will become more important as we prepare our ecosystems for a future characterized by increased climatic variability with an associated increase in frequency and severity of ecological disturbances.
Type:
text; Electronic Dissertation
Keywords:
Disturbance; Ecology; Forests; LiDAR; Metabolic Scaling Theory; Natural Resources; Carbon
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Natural Resources and the Environment
Degree Grantor:
University of Arizona
Advisor:
Falk, Donald A.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleCordilleran Forest Scaling Dynamics And Disturbance Regimes Quantified By Aerial LiDARen_US
dc.creatorSwetnam, Tyson Leeen_US
dc.contributor.authorSwetnam, Tyson Leeen_US
dc.date.issued2013-
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.abstractSemi-arid forests are in a period of rapid transition as a result of unprecedented landscape scale fires, insect outbreaks, drought, and anthropogenic land use practices. Understanding how historically episodic disturbances led to coherent forest structural and spatial patterns that promoted resilience and resistance is a critical part of addressing change. Here my coauthors and I apply metabolic scaling theory (MST) to examine scaling behavior and structural patterns of semi-arid conifer forests in Arizona and New Mexico. We conceptualize a linkage to mechanistic drivers of forest assembly that incorporates the effects of low-intensity disturbance, and physiologic and resource limitations as an extension of MST. We use both aerial LiDAR data and field observations to quantify changes in forest structure from the sub-meter to landscape scales. We found: (1) semi-arid forest structure exhibits MST-predicted behaviors regardless of disturbance and that MST can help to quantitatively measure the level of disturbance intensity in a forest, (2) the application of a power law to a forest overstory frequency distribution can help predict understory presence/absence, (3) local indicators of spatial association can help to define first order effects (e.g. topographic changes) and map where recent disturbances (e.g. logging and fire) have altered forest structure. Lastly, we produced a comprehensive set of above-ground biomass and carbon models for five distinct forest types and ten common species of the southwestern US that are meant for use in aerial LiDAR forest inventory projects. This dissertation presents both a conceptual framework and applications for investigating local scales (stands of trees) up to entire ecosystems for diagnosis of current carbon balances, levels of departure from historical norms, and ecological stability. These tools and models will become more important as we prepare our ecosystems for a future characterized by increased climatic variability with an associated increase in frequency and severity of ecological disturbances.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectDisturbanceen_US
dc.subjectEcologyen_US
dc.subjectForestsen_US
dc.subjectLiDARen_US
dc.subjectMetabolic Scaling Theoryen_US
dc.subjectNatural Resourcesen_US
dc.subjectCarbonen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineNatural Resources and the Environmenten_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorFalk, Donald A.en_US
dc.contributor.committeememberFalk, Donald A.en_US
dc.contributor.committeememberLynch, Ann M.en_US
dc.contributor.committeememberEnquist, Brian J.en_US
dc.contributor.committeememberYool, Stephen R.en_US
dc.contributor.committeememberGuertin, D. Phillipen_US
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