Heather Alexander is an assistant professor in forest ecology in Auburn University, United States. She is an expert in the areas of forest, fire and disturbance ecology. She studies the impacts of changing fire regimes of forest succession, dynamics influence of tree traits on forest flammability and the consequences of changing forest composition on forest ecosystem function. With Heather, we talked about the impacts of increasing wildfire severity on forests, how the melting permafrost affect them, the Sergei Zimov experiment and the Pleistocene Park project in Siberia, the benefits and cons of reforestation and offsetting programs, "playing God" with the environment and ecosystems, and scientists and the activism dilemma. Transcript and references of this episode are available on Go Simone's website: http://gosimone.org/episode-20-heather-alexander-forest-ecology/