Quantifying the impacts of toxicants on ecological populations

The closely related field of ecotoxicology and environmental toxicology have traditionally taken a reductionist approach and studied the effects of individual stressors on individual organisms. This approach fails to consider how multiple chemicals will affect populations and ecological systems. As an alternative, my doctoral research has focused on developing a population model and an interspecific competition model to better understand how pesticides and a simple mixture of pesticides affect natural systems. Using this system, I found that pesticides affect populations at levels not necessarily expected using traditional approaches. Specifically, malathion, pendimethalin, and permethrin were used as pesticides for the study system because they are found in the playa wetlands of the Southern High Plains. I also found that the mixture of pesticides was more toxic than the toxicity of individual pesticides, but the increase in toxicity was still difficult to quantify.