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In Our Own Backyard - Chapter 3 Extract

For many years, scientists worldwide have studied the effects of global warming and the news is not encouraging. In many areas of the world, species of plants and animals are disappearing at an alarming rate, unable to adapt to warmer temperatures and changes in rainfall. Here in Riverwoods, we sometimes applaud the fact that our winters seem less severe than those we remember as children. But what about the other changes, some so subtle that we don't consciously notice them until someone points them out? What about the monarch butterflies and delightful fireflies that populated the summers of our youth? And the frog sonatas that added such pleasure to our evenings? What about the disappearance of plants with undiscovered medicinal value? ...

At its best, our woodlands are a complex ecosystem of interdependent plant species designed to foster the active growth of oaks and other forest trees, as well as a variety of wildlife. This ecosystem consists of the canopy, the understory, shrubs and the plants of the forest floor. Each element has characteristic species. For example, ground plants include trillium, wild geranium, grasses, sedges and native vines such as Virginia creeper, while the understory includes ironwood, blue beech, hawthorn, and smaller trees and shrubs. The canopy is dominated by American basswood, ash, sugar maple, silver maple, black cherry, hickory, elm, hackberry, eastern cottonwood and oak species, but also includes black locust, northern catalpa, white pine, walnut, and willow trees.

In addition to its unique natural environment, Riverwoods is known for its ambience - the "feel" of the community that arises in large measure from the special connection the residents have to the natural surroundings. Unfortunately, the Riverwoods environment is being degraded and fragmented, creating barriers to wildlife, and reducing the ability of the woodlands to regenerate more desirable species. The causes include the proliferation of non-native, invasive plant species, over-browsing by an increased deer population, insect threats such as the gypsy moth, Asian long-horned beetle and emerald ash borer, and stress caused by changes in the water table.

We residents are perhaps the single greatest cause of woodland deterioration, as we replace natural growth and beneficial leaf and tree litter with buildings, pavement and large, cultivated areas (such as turf grass lawns) that fragment natural habitats, making them insufficient for supporting the full range of native plants and animals.

We all benefit from the fact that much of Riverwoods is a native woodland ecosystem. The woodlands minimize flooding by absorbing rainwater and snowmelt, thereby reducing runoff and erosion much more effectively than do cultivated areas. In addition, woodlands filter pollutants from storm water, cleaning and recharging the underground aquifer (from which many residents derive household water) and providing this area with cleaner recreational waterways. The trees also help clean our air, absorbing a variety of pollutants (especially the greenhouse gases that contribute to global warming) and reducing noise pollution by baffling sound from nearby roads. Finally, our woods provide nesting areas for birds and other wildlife, which in turn help in controlling a variety of insects. In all of these ways, our diverse woodland ecosystem protects and improves our overall quality of life.

A native ecosystem provides economic benefits as well. For example, the declining availability of wooded properties elsewhere results in higher property values for wooded sites. Also, our natural woodlands are relatively cost-effective, utilizing less water and, once established, requiring little care. Hardy native growth, adapted to local conditions over thousands of years, requires no fertilizer or pesticides, little or no irrigation, no weekly mowing, and minimal weeding. And then, there is the reduction in air conditioning costs, for the woodlands cool the surrounding air and provide shade. Clearly, preserving or re-establishing a natural wooded landscape provides significant savings of time and money.

The importance of a healthy and biologically diverse ecosystem cannot be over-stressed. When there is broad diversity of plant and animal life, any individual species is more able to withstand disease and pests, helping to ensure sustainability of the entire system. Finally, native trees, plants, and grasses provide wonderful visual appeal, displaying a huge variety of shapes, textures, heights and colors to delight our senses. ...

[In Our Own Backyard includes recommendations about landscaping in Riverwoods.]