In 2010 David retired as the founding Director of the Aldo Leopold Wilderness Research Institute, a position he held since 1994. Located in Missoula, Montana, the Leopold Institute is an interagency program that provides leadership in the development and application of knowledge related to the diverse ecological and human values of wilderness and similarly protected areas. Prior to moving to the Leopold Institute David spent 21 years as a research scientist for the National Park Service at Sequoia and Kings Canyon National Parks in California. In that position, he developed and coordinated research programs in the broad areas of visitor impacts, fire ecology and the effects of air pollution and climate change. He is a plant ecologist by training, having received a BA from the University of California at Davis and a PhD from Stanford University. He is widely recognized for his efforts to apply his ecological expertise to the application of science to management and policy issues in support of parks, wilderness and other protected areas. He is widely published with over 130 published peer reviewed journal articles, book chapters, and book reviews.
David currently holds appointments as an Emeritus Scientist for both the U.S. Forest Service and the National Park Service where he has worked with Sequoia and Kings Canyon National Parks to solidify the scientific background for their wilderness stewardship plan.