Reasons to be mindful of native trees and plants.
BY ANNA HANCHETT
Blog posts reflect the view of the author only.
Imagine that you have vacationed in Florida for several months and returned to an altered neighborhood, your house replaced by a shelter, yes, but one which didn’t serve your needs and where you couldn’t raise your children. More importantly, all the food available in your area is inedible, disturbing to your tastes and digestion. You’d think of moving on, wouldn’t you?
This is what happens to returning or hatching insects and migrating birds when we replace their natural habitat with non-native species of plants. Native plants are flora that have evolved naturally in a region, from the most delicate, tiny “weeds” to the most magnificent trees. They are the ecological foundation upon which the whole natural food web is built. And many of them are disappearing. In Massachusetts, 258 species of plants are considered endangered, threatened, or of special concern, and are protected under the state’s Endangered Species Act. These include Purple Milkweed, Upland Wild Aster, Large-Leaved Goldenrod, Swamp Birch, Mountain Alder, and Yellow Oak, to name a few.
We need them. Native plants and native wildlife have evolved together, each adapting specialized characteristics needed by the other. The shape and structure of flowers allows pollination only by specific insects. The chemical content of the leaves appeals to some native insects and birds and not to others. Some native plants bloom early, nourishing specific pollinators migrating north. Wild asters provide food for monarch butterflies on their autumn journey south. All these characteristics have co-evolved.
Enter our national obsession with well manicured lawns surrounded by exotic ornamental plants and foreign species of flowering trees. This taste for non-native plants has reduced a once ecologically continuous landscape by hundreds of millions of acres and left it about as useful to native insects, birds, and animals as AstroTurf, plastic flowers, and artificial Christmas trees. Removing native plants destroys the natural food web and starves the life that depends on it, from bacteria to insects and on to larger animals.
Insects hold up the feeding and reproductive structure of all things above them. In a study of the ecosystems available in ordinary yards, it was discovered that at least 70 percent of the plants must be native to enable common birds like chickadees to raise a normal number of chicks. It takes more than 6,000 caterpillars of a naturally edible type to feed a brood of chickadees to maturity. Trees, like the oaks that are native in New England, can support more than 500 species of native caterpillars. Non-native trees, on the other hand, may host fewer than 10 types of caterpillars, far too few to feed hungry broods of native birds. And these caterpillars may not even be edible. The birds in that area will either die out or move elsewhere.
The natural interaction of the whole local food web, from the smallest to the largest inhabitants, is interrupted. We also lose out as humans. We miss the joy and beauty of the multitude of insects, birds and animals that would thrive around us if the environment included native plants offering their native foods.
Exotic plantings and monocultures such as most lawns and, since the 1970’s, most agriculture, encourage non-native diseases and pests, resulting in large scale plant damage and use of pesticides, further enlarging the circle of destruction. By contrast, most native plants require little maintenance. They are adapted to local conditions and seed themselves into friendly areas. They also need less water, a vital and often scarce resource.
Local nurseries are beginning to offer native species of plants. When purchasing plants, always ask if they are native to our area. Also, make sure they have not been raised with the systemic pesticides that poison the insects, birds, and animals you are trying to encourage. You will come home with a plant, shrub or tree that will take its native and natural place, and fulfill its complex and vital role, in the landscape we share.