The boreal forest is one of the world's great ecosystems, stretching across North America and Eurasia in an unbroken band and containing about 25% of the world's closed canopy forests. The Kluane Boreal Forest Ecosystem Project was a 10-year study by nine of Canada's leading ecologists to unravel the impact of the snowshoe hare cycle on the plants and the other vertebrate species in the boreal forest. In much of the boreal forest, the snowshoe hare acts as a keystone herbivore, fluctuating in 9-10 year cycles, and dragging along secondary cycles in predators such as lynx and great-horned...