Biology ETDs

Publication Date

5-1-2012

Abstract

Although the Earths climate system has always been inherently variable, the magnitude and rate of anthropogenic climate change is subjecting ecosystems and the populations that they contain to novel environmental conditions. Because water is the most limiting resource, arid-semiarid ecosystems are likely to be highly responsive to future climate variability. The goal of my dissertation is to understand how precipitation variability affects primary productivity and soil respiration in desert grassland ecosystems. Initially, I reviewed the literature to understand how climate change affects net ecosystem exchange (NEE) across the warm deserts of North America (Chapter 2). Next, I examined the effects of precipitation frequency and intensity on soil moisture (θ), leaf-level photosynthesis (Anet), predawn leaf water potential (ψpd), aboveground net primary productivity (ANPP), and soil respiration (Rs) (Chapter 3). Last, I studied how large (10 mm) and extreme (30 mm) rainfall events with extended dry periods affected the ecophysiological response of two co-occurring dominant perennial C4 grasses, Bouteloua eriopoda and B. gracilis across an arid-semiarid ecotone (Chapter 4).

Project Sponsors

National Science Foundation grant to the University of New Mexico (UNM) for Long-Term Ecological Research (LTER), U.S. Department of Energy's Office of Science (BER) through the Western Regional Center for the National Institute for Climatic Change Research, T&E Inc., Sevilleta LTER Summer Fellowship, UNM Department of Biology Alumni Scholarships, UNM - Graduate Research Allocations Committee, Student Research Allocations Committee, Graduate Research Project and Travel Grant

Language

English

Keywords

Precipitation variability, Chihuahuan Desert grassland, Primary production, Soil respiration, Bouteloua eriopoda, Bouteloua gracilis

Document Type

Dissertation

Degree Name

Biology

Level of Degree

Doctoral

Department Name

UNM Biology Department

First Advisor

Collins, Scott

First Committee Member (Chair)

Pockman, William

Second Committee Member

Sinsabaugh, Robert

Third Committee Member

Nippert, Jesse

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