Seven reasons why we need trees

We have all noticed it lately while driving around the Kawartha Lakes. A farm goes up for sale. Once sold, the big machines go in and cut down the trees between the fields, often piling them up into piles for burning. Then the spring rains come. The field, without trees, doesn’t drain well. There are new boggy areas. The new landowner, at considerable expense, has someone come in to lay the long plastic pipes to tile, or drain, the field, in hopes that this will solve the problem. But this is not the only problem that has been created.

Often, trees are cut down with hope that this will increase the farm’s bottom line, without realizing that trees are essential to maintaining healthy fields.

Here are seven reasons why tree lines and hedgerows are essential for healthy fields and a healthy community.

1. Trees prevent erosion. Once tree lines are removed, it is much easier for topsoil to wash off the fields, especially in hard rainstorms. Trees hold the earth together and prevent it from washing away. In addition, when it is dry, trees act as windbreaks, preventing our topsoil from blowing away. In very dry springs, it is possible to drive alongside farms in our community and watch the dry earth blowing across the road. Tree lines prevent this from happening both by reducing the speed of the wind, and by catching dry earth before it blows off the field.
2. Trees absorb water. Rather than storm water rushing down the fields and off into ditches and roads, tree lines disrupt the flow, slowing the water so that it can be absorbed into the earth. Once absorbed, water runs down to the water table following paths made by the roots of the tree. This prevents water pooling in the fields in the spring, and means that the water table is higher so that the land is not bone dry during a drought. Rather than a field that is either extremely wet or extremely dry, trees create conditions that moderate the moisture in fields. In addition, the leaves of trees prevent hard rainstorms from pounding directly on the soil, by catching the raindrops and slowly releasing them from leaf to leaf before they hit the ground. This means that the earth is not caked from the hard impact of water, but able to absorb the smaller amounts that drip off the trees.
3. Trees release water into the atmosphere. The water that is absorbed during rain storms is drawn up by the tree and released into the atmosphere during transpiration. This moisture feeds the clouds that give us rain. Fewer trees mean less rain and more drought.
4. Trees catch fertility. As mentioned above, a tree line not only stops soil that is washing away when it rains, it also catches blowing soil and keeps it in the field. This means that fertility stays in the field rather than escaping into ditches or onto roads. In addition, the birds, animal and insects that live in a tree line add an enormous amount of fertility to the surrounding soil through their excretions. This fertility enriches the insect and bacterial life in the soil around the tree line, which in turn enriches the fields.
5. Tree lines and hedgerows reduce predator problems. Hedgerows provide habitat for many small mammals like rabbits, mice and other rodents. This is the natural food of coyotes and foxes. Removing tree lines means these animals disappear with the result that coyotes and foxes will try to find food in the only places that have accessible food: our farms.
6. Tree lines planted close to our houses help moderate the temperatures in our homes. In the winter trees can help to block freezing winds that push up our fuel costs. In the summer they provide shade, significantly cooling the temperature of our houses.
7. Studies have shown that landscapes of pastoral fields with trees and hedgerows create feelings of well-being in people. This is one of the reasons that tourists flock to our area of beautiful landscapes nestled among the lakes.

Before we assume that cutting down trees will only have beneficial affects in our farm or our yard, consider the many ways that trees enrich our soil, create habitat for animals, help control water, and give us a sense of well-being. Perhaps then we will realize that in cutting them down we lose far more than we gain.