IN PAST DECADES, THE SCIENTIFIC COMMUNITY HAS UNDERGONE A tremendous expansion and knowledge has increased proportionately. However, too often the accumulation of information is mistaken for knowledge that provides understanding and control. We can’t afford to make such an assumption, because it fosters the terrible illusion that we can “manage” wilderness and it has resulted in destructive consequences.
Globally, old-growth forests are being cleared with alarming speed. In the past decades, geneticists have made a surprising finding that foresters should heed. When seemingly homogeneous populations of organisms were analyzed using molecular techniques, they were unexpectedly found to be highly diverse. When looked at from individual to individual, the products of a single gene are found to vary considerably. Geneticists call such variability genetic polymorphism, and we now know that a characteristic of wild populations of any species is a high degree of genetic polymorphism. Apparently, maximum genetic diversity optimizes the chances that a species can withstand changes in the environment.
When individuals of the same species are compared, their patterns of genetic polymorphism differ from region to region. Thus, whether a tree, fish, or bird, different geographic subgroups exhibit different spectra of variation. So Ronald Reagan was dead wrong—if you see one redwood tree, you haven’t seen them all. Stanford ecologist Paul Ehrlich says, “The loss of genetically distinct populations within species is, at the moment, at least as important a problem as the loss of entire species.”
The biological value of diversity can also be applied to a collection of species. A forest is more than an assemblage of trees; it is a community of plants, animals, and soil microorganisms that have evolved together. This aggregate of species creates a highly resilient forest with a great capacity to recover from fire, flooding, landslides, disease, selective logging, or storm blowdowns. That’s because the diverse species remaining in the surrounding areas can replenish the damaged parts. Clearly, we should try to maximize forest diversity by protecting as many old-growth forests as possible. That’s the best way to ensure the maintenance of a broad genetic base on which the future of the forestry industry will depend.
There is a way to illustrate the power of diversity by looking at our bodies. Just as a forest is made up of vast numbers of individuals of different species, we are an aggregate of some 100 trillion cells that vary in size, shape, and function. These different cells are organized at many levels into tissues and organs that all come together in a single integrated whole—a functioning body.
The collective entity that is each of us thus is a mosaic of an immense array of different cell, tissue, and organ types that have enormous resilience and recuperative powers. If we suffer a cut, bruise, or infection, the body has built-in mechanisms to overcome the assault. We even have the ability to regenerate skin, liver, blood, and other body parts and compensate for damage to the brain and circulatory systems. We can function pretty well with the loss of some body parts, such as a digit, tonsils, or teeth. In short, our bodies can absorb considerable trauma and recover well, a tribute to cellular diversity in form and function.
If we amputate large parts of the body, we can still function and survive. Thus, we can live with the loss of limbs, eyes, ears, and other parts, but each loss confers greater dependence on other people and on human technological ingenuity to compensate for lost abilities. With the power of modern science and high technology, we can make artificial substitutes for teeth, bones, skin, and blood, and we have even devised machines to take over for the heart, lungs, and kidney. In principle, it should be possible for an individual to survive the combined loss of organs that are not absolutely necessary for life and those that can be mimicked by machines. Thus, a blind, deaf, quadruple amputee who is hooked to a heart-lung and kidney machine could live and would still be a person, but one with capabilities and resilience radically restricted in comparison with a whole individual. Essentially, such a patient would be a different kind of human being, created by and dependent upon human expertise and technology.
In the same way, a forest bereft of its vast biodiversity and replaced by a limited number of selected species is nothing like the original community. It is an artifact created by human beings who foster a grotesque concept of what a forest is. We know very little about the basic biology of a forest community, yet road building, clear-cut logging, slash burning, pesticide and herbicide spraying, even artificial fertilization have become parts of silviculture practice. The integrity of the diverse community of species is totally altered by such practices with unexpected consequences—loss of topsoil, death from acidification, weed overgrowth, disease outbreak, insect infestation, and so on. But now, caught up in the mistaken notion that we have enough knowledge about forests to “manage” them in perpetuity, we end up ricocheting from one contrived Band-Aid solution to another. Medical doctors today are struggling to readjust their perspective to treat a patient as a whole individual rather than as an aggregate of autonomous organ systems and ecopsychology recognizes the relevance of our surroundings on our psychological health. A similar perspective has to be gained on forests. The key to development of sustainable forests must reside in the maintenance of maximum genetic diversity both within a species and between the species within an ecosystem. If we begin from this basic assumption, then the current outlook and practices in forestry and logging have to be radically overhauled.