Dr. Hamburg's research is directed towards understanding the role of human disturbance on the structure and function of terrestrial ecosystems. Over the past several decades we have come to realize that there are very few places unaffected by human disturbance, and therefore ecological research needs to consider the potential role that past and present human influence has had on the patterns and processes that we study. The disturbances that he is interested in are not just the obvious ones, e.g. cutting trees or plowing soil, but also the more subtle influences, e.g. air pollution or changes in harvesting technologies. He studies these human influences by looking at their impacts on nutrient cycles, plant community composition and ecosystem productivity. Such ecosystem level research is best accomplished in the frame work of broad long-term interdisciplinary research sites. As a result of his strong interest in such sites Dr. Hamburg has been actively involved in helping to establish an international long-term ecological research network.