The Consequences of Buffelgrass Pasture Development for Biodiversity in the Southern Sonoran Desert

Persistent Link:
http://hdl.handle.net/10150/195818
Title:
The Consequences of Buffelgrass Pasture Development for Biodiversity in the Southern Sonoran Desert
Author:
Franklin, Kimberly Anne
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:
Decades of overgrazing have left many rangelands in northwestern Mexico in poor condition. This has led to the practice of converting native rangeland plant communities to buffelgrass pastures. Buffelgrass (Pennisetum ciliare) is a perennial bunchgrass native to Africa. Both the extent of buffelgrass pastures within Mexico and the impacts of land conversion on biodiversity and ecosystem functioning. In the present study I address the effects of land conversion on the productivity and diversity of rangelands in the southern Sonoran Desert in the state of Sonora, Mexico. First, using satellite imagery from the Landsat mission, I found that rates of land conversion in the most heavily affected region of Sonora have continued to accelerate over the past three decades and that productivity of buffelgrass pastures is lower than that of native rangeland. Next, I examined the impacts of land conversion on the diversity and structure of plant communities and ant assemblages across a rainfall driven gradient of productivity in central Sonora. The regional extent of this land use change allowed me to explore the interaction between site productivity and land conversion. Within native rangeland I detected strong positive relationships between productivity and the species richness of perennial plant communities, but only weak positive relationships between productivity and species richness of ant assemblages. These results were discussed in the context of species diversity theory. Land conversion reduced the species richness of perennial plant communities by approximately 50% at both local and regional scales, whereas the species richness of ant assemblages was reduced by 17% at the local scale and only 8% at the regional scale. I found no evidence for an interaction between site productivity and land conversion in either plant communities or ant assemblages. The implications of these findings for long-term trajectories of biodiversity in the southern Sonoran Desert are discussed.
Type:
text; Electronic Dissertation
Keywords:
ants; biodiversity; diversity; productivity; rangeland; remote sensing
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Insect Science; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Markow, Therese
Committee Chair:
Markow, Therese

Full metadata record

DC FieldValue Language
dc.language.isoENen_US
dc.titleThe Consequences of Buffelgrass Pasture Development for Biodiversity in the Southern Sonoran Deserten_US
dc.creatorFranklin, Kimberly Anneen_US
dc.contributor.authorFranklin, Kimberly Anneen_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.abstractDecades of overgrazing have left many rangelands in northwestern Mexico in poor condition. This has led to the practice of converting native rangeland plant communities to buffelgrass pastures. Buffelgrass (Pennisetum ciliare) is a perennial bunchgrass native to Africa. Both the extent of buffelgrass pastures within Mexico and the impacts of land conversion on biodiversity and ecosystem functioning. In the present study I address the effects of land conversion on the productivity and diversity of rangelands in the southern Sonoran Desert in the state of Sonora, Mexico. First, using satellite imagery from the Landsat mission, I found that rates of land conversion in the most heavily affected region of Sonora have continued to accelerate over the past three decades and that productivity of buffelgrass pastures is lower than that of native rangeland. Next, I examined the impacts of land conversion on the diversity and structure of plant communities and ant assemblages across a rainfall driven gradient of productivity in central Sonora. The regional extent of this land use change allowed me to explore the interaction between site productivity and land conversion. Within native rangeland I detected strong positive relationships between productivity and the species richness of perennial plant communities, but only weak positive relationships between productivity and species richness of ant assemblages. These results were discussed in the context of species diversity theory. Land conversion reduced the species richness of perennial plant communities by approximately 50% at both local and regional scales, whereas the species richness of ant assemblages was reduced by 17% at the local scale and only 8% at the regional scale. I found no evidence for an interaction between site productivity and land conversion in either plant communities or ant assemblages. The implications of these findings for long-term trajectories of biodiversity in the southern Sonoran Desert are discussed.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectantsen_US
dc.subjectbiodiversityen_US
dc.subjectdiversityen_US
dc.subjectproductivityen_US
dc.subjectrangelanden_US
dc.subjectremote sensingen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineInsect Scienceen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorMarkow, Thereseen_US
dc.contributor.chairMarkow, Thereseen_US
dc.contributor.committeememberMolina-Freaner, Franciscoen_US
dc.contributor.committeememberCarriere, Yvesen_US
dc.contributor.committeememberMarsh, Stuarten_US
dc.contributor.committeememberWheeler, Dianaen_US
dc.identifier.proquest10416en_US
dc.identifier.oclc659752153en_US
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