The Human Component of Restoring Tamarix Invaded Land
Lisa Clark1, Anna Sher2, Eduardo González3,4, Annie Henry5, Rebecca Lave6, and Nathan Sayre7
1 University of Denver, Dept. of Biological Sciences, Denver, CO; lisa.clark@du.edu
2 University of Denver, Dept. of Biological Sciences, Denver, CO; anna.sher@du.edu
3 Colorado State University, Department of Biology, Fort Collins, CO, USA
4 University of Denver, Department of Biological Sciences, Denver, CO, USA; edusargas@hotmail.com
5 University of Denver, Dept. of Biological Sciences, Denver, CO; annielh108@gmail.com
6 Indiana University, Dept. of Geography, Bloomington, IN; rlave@indiana.edu
7 University of California, Dept. of Geography, Berkeley, CA; nsayre@berkeley.edu
What aspects of managers and management are important for successful restoration? Here we propose new methodologies for characterizing restoration practitioners/managers in the context of a case study of Tamarix removal projects in the American southwest. We surveyed 45 managers associated with 244 Tamarix removal sites where vegetation had been quantified by species. Quantitative and qualitative data were collected from these managers to determine whether there were identifiable groups based on manager characteristics, project-specific characteristics, general management decisions, project-specific decisions, or by geographic location. To do this, we ran cluster analyses on their answers to standardized questions using Gower distances and the Partitioning Around Medoids (PAM) method. This novel approach allowed us to combine categorical, ordinal and continuous variables, and could still be computed with missing values present. Clusters were then used to explore relationships with other variables including the plant communities themselves. We found that whom the manager worked for (i.e., which agency) and which agencies owned, managed, and did the hiring for a project were primary distinguishing features, appearing to influence project goals, methodologies, and resulting plant community. In contrast to other published works, we did not find that either education or attitude toward science was important for explaining outcomes. Furthermore, our results suggest that managers of Tamarix removal projects are following scientists’ recommendations for this system, utilizing multiple means of monitoring and aligning project goals with site condition. The role of RiversEdge West (previously Tamarisk Coalition) for connecting groups and providing information figured prominently in the interviews. This research thus may represent a success story for the role of science in restoration, while providing a broadly-applicable method to evaluate diverse data from surveys.