This Figure Set explores the complexity of forest ecosystems with particular emphasis on the effects of expanding white-tailed deer (Odocoileus virginianus) populations on trees, birds, and people. Once at the brink of extinction throughout their range, deer populations in the eastern and midwestern United States have grown rapidly over the last several decades. This has created unwelcome consequences for farmers, orchardists, homeowners, and motorists, including crop damage and more vehicle accidents. Of concern to conservation biologists is the possibility that high deer densities might have detrimental effects on the abundance and diversity of forest vegetation and wildlife. This issue addresses the questions: 1) How do deer impact the composition of forest vegetation? 2) How do deer influence habitat for other wildlife? and 3) What challenges exist in the management of white-tailed deer populations? The issue draws upon three primary papers, which examine: 1) deer browse and other factors influencing hemlock regeneration, 2) effects of manipulating deer populations on the abundance and diversity of breeding birds, and 3) decision-making processes for resolving deer management controversies.