In this chapter, the authors discuss the role of browsing by mammals upon recruitment of trees and shrubs during plant succession in boreal forests. Radiation, soil temperature, and nutrient availability decline sharply through succession in Alaska, and they are probably the primary factors responsible for successional change. However, these changes in environment influence: (1) patterns of selective feeding by browsing mammals through allocation of carbon-to-plant secondary metabolites: and (2) the capacity of woody plants to replace tissue eaten by browsing mammals through compensatory growth. The interplay of these two factors determines the role of browsing upon plants during boreal forest succession.