Human Impacts in Pine Forests: Past, Present, and Future*

Pines (genus Pinus) form the dominant tree cover over large parts of the Northern Hemisphere. Human activities have affected the distribution, composition, and structure of pine forests for millen- nia. Different human-mediated factors have affected different pine species in different ways in different regions. The most important factors affecting pine forests are altered fire regimes, altered grazing/ browsing regimes, various harvesting/construction activities, land clearance and abandonment, purposeful planting and other manip- ulations of natural ecosystems, alteration of biotas through species reshuffling, and pollution. These changes are occurring against a backdrop of natural and anthropogenically driven climate change. We review past and current influence of humans in pine forests, seeking broad generalizations. These insights are combined with perspectives from paleoecology to suggest probable trajectories in the face of escalating human pressure. The immense scale of impacts and the complex synergies between agents of change calls for urgent and multifaceted action.