Nowhere is nature more lavish in her gifts to us than in the forest.
Some of these gifts are obvious. Wood from the forest heats and shelters us and gives us material for making hundreds of valuable items. The forest itself protects and nourishes its other inhabitants, and offers us game and berries, birds and mushrooms, maple syrup and wildflowers.
But the greater, more fundamental gifts of the forest can easily be overlooked.
Pure water is one. The forest soil is able to absorb precipitation and meltwater, filter it, store it and slowly release it. This beneficial action is due to the loose structure of a naturally grown and undisturbed forest soil. It represents a magnificent system of pores, major cavities and soil particles, developed over a long period of time from fallen leaves and needles, from expired birds and animals and other forest dwellers, and from the invisible activity of countless soil organisms.
This looseness results in an exceptionally high permeability to water. How high? Experiments made years ago by the Swiss Forestry Research Institute showed that the seepage time for a 4-inch column of water on a waterlogged pasture was 100 minutes, on a drained pasture 38 minutes, in a 20-year-old forest eight minutes, and in a 40-year-old forest a mere three minutes.
Because of this high permeability the water reaching the forest floor, even in the event of heavy rain or very rapid thaw, penetrates almost completely into the soil and there feeds springs and aquifers. Not only does the forest conserve and store water for us all, it also protects against flooding and erosion and filters impurities out of the water.
As if that weren't enough, the forest also regulates and cleans our air supply. The tree canopy acts as a filter that traps the dust and soot particles from passing air. Every rain washes the filter clean again and restores its absorptive capacity.
According to several studies, conifer trees can trap from 12 to 14 tons of dust each year per acre, the broadleaf species up to 70 tons.
In addition, trees (and other green plants) are the main source of our planet's oxygen. Nearly all life forms require oxygen to sustain themselves.
But the massive burning of fossil fuel required to support our modern way of life has clearly upset the global oxygen balance. Quite apart from the enormous quantities of toxic sulphur compounds emitted into the air by these sources (and which for some decades threatened our lakes and forests alike in the form of acid rain), the amount of oxygen consumed is replaced by an increased quantity of carbon dioxide, which contributes directly to climate change.
As a massive vegetation cover, the forest is of inestimable and vital importance to the regeneration of the air we breathe. Every patch of woodland, however small, (indeed, each tree) is a dust trap for air pollution and serves as an ongoing oxygen factory.
Then, too, the forest protects us against wind, against noise, against temperature extremes and against visual pollution. But perhaps its greatest gift is that it allows us to rediscover, in its calm and greenery, a renewed sense of who we really are.
In the forest we unwind, draw a deep breath and realize with relief that our anxieties and fears are not the whole of life. In the healing presence of the woods, we sense continuity and a quiet joy, and dare to resurrect forgotten wonder.
Collections of Craig Nagel’s columns are available at CraigNagelBooks.com.