“The last word in ignorance is the man who says of an animal or plant: `What good is it?’ If the land mechanism as a whole is good, then every part is good, whether we understand it or not. If the biota, in the course of aeons, had built something we like but do not understand, then who but a fool would discard seemingly useless parts? To keep every cog and wheel is the first precaution of tinkering.”
Aldo Leopold, A Sand County Almanac
A healthy wildlife population has value in its own right – it belongs in the ecosystem and each species plays an important role. Stuart Hill, a McGill University entomologist and organic agriculture advocate, makes the point that 99% of all organisms are benign from a `pest’ point of view. When we encourage monocultures, we inevitably succumb to pesticide dependencies. Pesticides kill many non-target organisms. Each time we kill a non-target organism, we inherit its job in the system. We don’t even recognize what most of these jobs are and even when we do, we don’t perform them very well.
Insects, soil-dwelling organisms, invertebrates, fungi, etc. help break down decaying matter and make nutrients available for plants; birds help control the insects that can harm plants (a study in Washington State estimates that given the amount of spruce budworms eaten by evening grosbeaks, it would cost at least $1,820 per square km (.6 square miles) per year over a 100-year rotation to spray with insecticides to produce the same mortality); squirrels and birds play important roles in spreading seed; animals are very quick composters, turning plants into nutrients that are readily available to growing plants, which produce more food.
The point here is that natural systems are complex and involve vast numbers of interactions. Chris Maser describes a good example of such an interaction in The Redesigned Forest. He looked at just one role that northern flying squirrels play in Oregon’s old growth forests. These squirrels nest in the canopy of large trees and come down to the forest floor at night to feed. In the squirrel’s fecal pellets, Maser found spores of mycorrhizal fungi (the `seeds’ for new fungus), nitrogen-fixing bacteria (that will grow in the new fungi and fix atmospheric nitrogen for the tree) and yeast (a nutrient source that stimulates growth and nitrogen-fixing in the bacteria). These pellets are perfect inoculants to improve tree growth. As the squirrel travels along the forest floor, it litters the area with these pellets. Mycorrhizal fungi infect tree roots and become part of the cellular structure. Infected trees are much healthier than those not infected. We have no idea if this exact relationship exists here but no doubt many similar relationships do. The common chanterelle mushrooms are mycorrhizal and northern flying squirrels live in our forests. This is just one example of how complex the ecosystem is and how little we know about the effects of our intervention.
What do we gain from healthy forest communities? A resilient forest with a wide range of species can translate directly into dollars from forest products, purify ground water, store carbon and provide a natural classroom where ecology can be taught and studied. Exciting, ever-changing areas allow us to observe the native flora and fauna of our Island – a natural landscaped garden that requires little maintenance. Forests also provide opportunities for tourism, recreation and spiritual pursuits.