We examined if trees’ cooling services in Asheville are distributed equitably because previous studies have shown inequitable relationships exist between demographic factors and both tree canopies and the cooling services of trees. The results were too weak for policy recommendations because the natural science study design did not work well with the social science design, so here we focus on improving the natural and social science study designs for equity analyses of trees’ ecosystem services. First, the 1,000-point tree survey did not cover the Census block groups well, so we dropped areas of the city from our analysis. Our results kept changing as we reduced our sample size, so those omissions could be important. Second, using heat maps to measure the cooling effects of trees would require a design to summarize those effects across a block group and its residents. Third, impervious surfaces, daytime versus nighttime, water bodies, and elevation need to be meshed into the social science design. We conclude that only by carefully integrating natural and social science aspects in the study design can equity issues be assessed and good policy recommendations developed.
- David Martin, Ph.D., Professor of Economics and Environmental Studies, Davidson College