October 2003 Vol. 6, No. 2
Restoring Natural Systems Through Natural Processes by Dr. Melissa Savage, The Four Corners Institute Restoration is a roadmap for repairing natural ecosystems that have been damaged by human activities. In the Southwest, grasslands, bosques, and forests have changed dramatically over the past century by intensive land uses. Natural structures and processes have been altered by historical overgrazing, water diversion, fire suppression, logging, exotic species introductions, predator control, and many other influences, some of which are mainly activities of the past. But history matters in natural ecosystems. Even if damaging activities stop, ecosystems may not be able to return to their historical conditions by themselves, or perhaps not in the foreseeable future. Responsibility A general consensus has emerged that humans bear a responsibility for restoring damaged ecosystems. It is also clearly in our best interests to do so. Southwestern
ponderosa pine forests, for example, now densely packed with trees as a result of decades of “Smokey the Bear”
Editor’s Note This is the second in our series of newsletters on “Nature’s Model.” Here we explore issues surrounding restoration of our forest ecosystems and how that can be accomplished in such a way as to “kickstart” natural processes which have been interrupted by years of overlogging, overgrazing, and fire suppression.
policies, threaten our towns and villages with conflagrations. Historically, these pine forests burned often and with low-intensity fires whose flames usually reached only a few feet in height. These surface fires burned lightly through the forests, thinning young trees but preserving the old, fire-resistant pines. Open groves of trees with grassy understories resulted, and this forest structure supported unthreatening fires. The fires created the forest structure which, in turn, supported these kinds of fires. How, then, can we return ecosystems in the Southwest to more healthy, sustainable conditions? One approach is to alter the current structure of ecosystems to mimic natural structures. Exotic tree species, such as Russian olive and tamarisk, can be cleared from riparian communities. Small trees can be thinned from the pine forests. But if we do so, what will
(con’t on page 20)