Date of Award:
5-2007
Document Type:
Dissertation
Degree Name:
Doctor of Philosophy (PhD)
Department:
Wildland Resources
Department name when degree awarded
Wildland Resources
Committee Chair(s)
Ronald J. Ryel
Committee
Ronald J. Ryel
Committee
Christopher Neale
Committee
Tom Monaco
Committee
Scott Jones
Committee
Doug Johnson
Committee
Mike White
Abstract
Understanding the carbon cycle of major ecosystems is important in predicting feedback responses of the terrestrial biosphere to climate change. Bromus tectorum dominated ecosystems currently cover 7% of the Great Basin and represents a major land cover type for the region. This study looked at the carbon cycle of a near monoculture field of B. tectorum in southeastern Idaho, USA. A major portion of the study was dedicated to measurement validation because of the disagreement among techniques used to measure net ecosystem exchange (NEE) of CO2 between the atmosphere and terrestrial ecosystems . NEE, net photosynthesis, and canopy and soil respiration were quantified for the B. tectorum stand using multiple methods. This allowed for comparisons among measurement techniques and permitted the calculation of a best estimate of NEE. The study found that the eddy covariance technique underestimated NEE at night for the B. tectorum stand and the magnitude of underestimation increased with increasing leaf area index of the plant canopy. Annual NEE estimated by eddy covariance for the year 2005 was over four times lower than the best estimate of -80 g C m-2 yr-1 determined by a combination of methods. Implications are that many studies currently underestimate NEE and productive systems underestimate NEE more than less productive systems.
Checksum
4ad56f901e04c7c1b368c0a99e92c090
Recommended Citation
Myklebust, May Christin, "The Carbon Cycle of a Semi-Arid Grass System, Bromus tectorum" (2007). All Graduate Theses and Dissertations, Spring 1920 to Summer 2023. 6617.
https://digitalcommons.usu.edu/etd/6617
Included in
Copyright for this work is retained by the student. If you have any questions regarding the inclusion of this work in the Digital Commons, please email us at .