Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Watershed Sciences


Todd A. Crowl


Over the past 100 years, riparian vegetation communities throughout the Southwest United States have been extensively invaded by Tamara spp. (saltcedar). Saltcedar derives its common name from its physiological adaptation to excrete salts. The

production of Tamarix detritus with associated secondary chemicals may affect the quality

of aquatic invertebrate food and habitat resources. An alteration in food and habitat quality may affect the composition and structure of aquatic invertebrate assemblages.

A series of experiments was conducted contrasting aquatic invertebrate assemblage densities, colonization rates, and growth rates associated with Tamarix versus native vegetation, Populus fremontii (cottonwood) and Salix exigua (willow), to determine if

aquatic invertebrate assemblages have been altered by the invasion of Tamarix. Results of invertebrate growth rates over 13 weeks indicate that Tamarix is minimally different in food quality to cottonwood and willow. I failed to find differences in invertebrate colonization rates or invertebrate assemblage densities associated with Tamarix compared to cottonwood and willow over two 6-week time periods.