Foresters can guide forests to old growth, but because forests are dynamic, living systems they cannot be preserved forever and someday a new forest will grow in it's place. By the simple fact of numbers, it can be seen that forests are managed for sustainability. Ever since the end of widespread agricultural clearing in the early 1900's, our forests have grown. The volume of standing timber can only increase when we harvest less timber than is available for harvest. This statement thus shows that for the last 50 years America's forests have been managed sustainably.
Wood products come from a resource that grows, matures and is replanted for future generations.
Producing steel materials require 3 times as much energy as wood products and 16 times as much clean water. When wood is done being used, it can be returned to the earth. Thus our forests and our trees are renewable natural resources .