Green building without building over the green
By Kevin Caldwell on 03/16/2006
The southern Appalachian region is one of the most biologically rich eco-regions in the Northern Hemisphere. The land draws people nationwide, and the record number of homes popping up means this biodiversity is being scraped into oblivion. Much of the damage is avoidable, and conservation development, or the practice of developing while preserving the natural history and wild space on a given piece of land, is helping reduce many otherwise large impacts.
Western North Carolina’s blossoming green-building industry reduces environmental impacts with “green” construction materials and methods and energy-efficient home designs. Owners of green homes base their plans on ecology to ensure the home is on the greenest site. This is done before construction by land planning and taking inventories of botany, wildlife and physical features. Conservation aims to protect rare species and their habitats, unfragmented forests, wildlife habitats, richness of native species, streams and wetlands, and it aims to ensure natural-resource sustainability and ecological patterns across the landscape.
Today, NC loses 172 square miles (110,000 acres annually / 300 acres daily) to permanent developments, and development is increasing.
Ranging from Pennsylvania to Alabama, this region defines the southern stretch of one of Earth’s oldest mountain chains. These ancient mountains eroded over geological time, and we now see them between about 900 feet and 6,680 feet high. We live within one of two temperate rain forests on Earth, formed some 55 million years ago. Before industrial clear-cutting in the early 1900s, most of eastern North America received more than 80 inches of rainfall a year, and many areas still receive about that much.
The southern Appalachians contain more than half of all flowering plant and fern species known in North America on only 2 percent of its land surface. North Carolina houses more than 7,500 wildlife and plant species, 1,200 of which are state rare-list species. Hundreds of common to rare endemic species (those limited to a region) are home here, alongside remnant tropical plants. Similarly, rare natural communities, including swamp forests, alluvial forests, bogs, rocky summits, and variations of common forest types, hide out in the hills here. Habitat loss, degradation and fragmentation of natural areas for natural-resource extraction and development are the greatest threats to biodiversity worldwide. Most losses are permanent and ongoing, resulting in a homogenization of nature across vast areas.
Though forested on appearance, today’s landscape pales against conditions that existed before industrialization. Gone are the woodland buffalo, coves of ginseng and goldenseal, elk, passenger pigeons, chestnuts, Carolina parakeets, lake sturgeons, cougars, bottomland canebrakes, gray wolves, and valley mosaics of beaver ponds, swamp forests, bogs and pools long since drained for farming. Since 1492, more than 600 plant and animal species have become extinct in North America from direct killing and habitat loss. While these species were driven off, original forests yielded an average of 75,000 to 100,000 board feet of timber an acre and occasional 25,000-board-foot trees. Today’s volume averages some 5,000 board-feet an acre, which is a loss of 90 percent to 95 percent of the original volume that nature produced over thousands of years. “Board feet” is a volume of lumber measurement equal to 1 inch by 12 inches by 12 inches, or 144 square inches.
Today, North Carolina loses 172 square miles (110,000 acres annually, 300 acres daily) to permanent developments, which are increasing. Nearly 84 percent of the region is privately owned, which means most land eventually will be developed. More than 50 percent of the Significant Natural Areas designated by the North Carolina Natural Heritage Program (NCNHP) are unprotected. Daily, we lose untold numbers of wildlife and plant species and their habitats to development without even a baseline record of what’s being lost. Salting the wounds are hoards of invasive-exotic plants easily establishing themselves on freshly excavated soils, where they rapidly reproduce, spread adjacent native ecosystems and begin evicting the natives. Still, this region is a center of biodiversity in North America. We can reduce impacts through biological inventories and thoughtful planning before building.
The following guidelines help minimize unnecessary impacts during and after development. They’re best suited on intact, undeveloped lands rather than on urban and other developed areas although most are applicable on any raw land.
- Invite a land-trust official to look at the land first if you think the tract deserves protection. Do not survey lots (especially inholdings) or plan roads and home sites before assessing the land because this negates the property’s conservation value.
- Explore the land intensely before you build. Over time, this allows ideas to mature that will improve conservation and construction.
- Never build on the areas you love the most. Save them and visit frequently.
- Maintain the largest amount of undeveloped, protected acreage as possible, and protect large core areas when possible.
- Maintain natural-area connectivity with vegetated areas on adjacent lands. For example, leave the undeveloped area of your land against undeveloped areas on adjacent parcels. Talk with your neighbors about creating larger protected zones across properties.
- Protect streams and wetlands with 100-foot-minimum no-touch vegetated zones, and avoid stream crossings.
- Avoid prominent and visible ridgeline home sites.
- Inventory, identify and protect rare natural communities, rare species and their habitats to the extent possible. This process will also reveal other management needs.
- Create clustered home sites in the smallest possible area, if the terrain allows, while maintaining privacy.
- Concentrate home sites and driveways near road entries to avoid daily auto and human activity through the heart of the land.
- Minimize soil impacts by building roads and drives along contours when possible while avoiding switchbacks. Use native erosion-control mixes, and re-vegetate disturbed areas with natives when possible.
- Road-building is best done in the growing season (mid-March to early October), so erosion-control seed mixes can establish quickly.
- Clearing trees and shrubs is best done between leaf-off (i.e. fall, when the leaves fall off) and leaf-on (i.e. spring) to avoid direct disruption of migratory bird-nesting and exposure of trees to air-borne pathogens on damaged bark and branches. Winter tree damage is far less harmful than growing-season damage, when vegetation is actively pumping nutrients.
- Consider potential off-site damage to adjacent properties from erosion, exposure and other things. Your actions might directly affect your neighbors, so talk about what you’re doing.
- Stockpile the native topsoil from construction zones. Even a small amount helps.
- Move native plants from road and home excavation sites. Many herbs and shrubs can be rescued and banked for future home plantings or moved to their habitats on site. Around the home, plant the dominant plants from the impacted natural community before planting regionally native plants not native to your site. Lastly, divide and plant from the native plant stock within their non-impacted areas to help mitigate for your impact.
Appalachian biodiversity and beauty awe natives and newcomers, yet we destroy the very resource we love. The inventory and planning processes increase, not decrease, our conservation and construction options. By not knowing what’s on our property, conservation is random and unplanned, like building a home without a blueprint. When we incorporate the natural heritage of the land into our plans, we add responsibility for the land to our self-given right to do what we want.
[Kevin Caldwell is a biologist with Equinox Environmental in Asheville. He is former owner of Appalachian Ecological Consultants and has worked with the Sweet Water Trust of New England, the Kentucky Natural Heritage Program, Merck Forest and Farmland Center in Vermont and Gaia Herbs in Brevard. He can be reached by e-mailing Kevin@equinoxenvironmental.com.]