browse line

If you see a forest where the vegetation looks as if it has been neatly trimmed to a height of about five feet, this browse line is an almost certain sign that deer numbers have grown too high. With too few predators to control their numbers, and with favorable niches opened by agriculture and suburban development, deer numbers often explode, to the point that the animals first overgraze the herbaceous plants of the forest floor, and then stretch as high as they can reach for twigs and other woody browse. The realization expressed in “Thinking Like a Mountain,” that a mountain therefore “lived in mortal fear of its deer,” was part of what convinced Aldo Leopold to stop shooting wolves and help start the infant science of wildlife management.

Bill McKibben