Tuesday, August 4, 2009
Exhibit Hall NE & SE, Albuquerque Convention Center
Matthew K. Chew, Center for Biology + Society, Arizona State University, Tempe, AZ, Juliet C. Stromberg, School of Life Sciences, Arizona State University, Tempe, AZ, Edward P. Glenn, Environmental Research Laboratory, University of Arizona, Tucson, AZ and Pamela L. Nagler, Southwest Biological Science Center, U.S. Geological Survey, Tucson, AZ
Background/Question/Methods Scientific research papers and review articles are an important avenue for conveying information to resource managers regarding ways in which introduced species modify ecosystems. The biases of the authors can shape the message that is conveyed. Our objective was to assess ways in which scientists have contributed to perceptions of Tamarix, an introduced plant species that is now abundant in western USA. Originally introduced to western USA to provide ecosystem services such as erosion control, Tamarix by the mid 1900s had became vilified as a profligate waster of water. This large shrub continues to be indicted for various presumed environmental and economic costs, and millions of dollars are expended on its eradication. To accomplish our objective, we conducted a qualitative review of published research on Tamarix, focusing on review articles Results/Conclusions
Our review indicates that scientists have played a key role in driving changes in perceptions of Tamarix from valuable import to vilified invader, and (in some instances) back to a productive member of riparian plant communities. Over the years many scientists have sustained a negative perception of Tamarix by, among other things, 1) citing outdated or anecdotal sources or otherwise citing sources inappropriately, 2) inferring causation from correlative studies, 3) applying conclusions beyond the domain of the original studies, and 4) emphasizing findings that present the species as an extreme or unnatural agent of change. As a result of these actions, a mythology has propagated indicating that Tamarix evapotranspires more water than other woody riparian species, routinely salinizes habitats, consistently provides inferior habitat for migratory songbirds including the endangered southwestern willow flycatcher, and sustains little to no biodiversity. Recent research is challenging the prevailing dogma regarding Tamarix's role in ecosystem function and habitat degradation, and many scientists now recommend management shifts from “pest plant” eradication to systemic, process-based restoration.
