Fall 2005

What is Forest Fragmentation?

The 2002 Southern Forest Resource Assessment defined forest fragmentation as the breaking up of large, contiguous (touching one another) forested tracts into smaller or less contiguous tracts. This means that forests become islands and peninsulas—patches of woods disconnected from one another by roads, farms, suburbs, cities, and other human activities.

Why Should We Care About It?

Forest fragmentation has a wide range of effects on ecosystem services, defined simply as the benefits that forests provide to us. In addition to providing wood products, fuel, medicine, and recreation, forests:

• Clean our water and air
• Provide habitat to a huge diversity of life forms
• Take up carbon dioxide and produce oxygen
• Regulate climate by sequestering carbon
• Maintain the health of soil
• Absorb and detoxify pollutants
• Provide the setting for a wide range of recreational activities

When forests are divided into smaller and smaller parcels, the biological diversity of native animals and plants is diminished, water cycles are altered, nonnative invasive plants and animals are introduced, and air and water quality are affected. Forests weakened by fragmentation become more susceptible to damage from insects and diseases, and coming under stress, often degenerate into a condition of chronic ill health.

In the South, the highest concentrations of intact interior forests are on public lands in the Blue Ridge Mountains, the Cumberland Plateau, and the Allegheny Mountains. The lands surrounding these intact forests are, unfortunately, highly susceptible to fragmentation from roads and increasing development. Other areas especially susceptible include the Ozark and Ouachita Mountains in Arkansas, the Piedmont of North Carolina, and areas in the Mississippi River Valley, west Coastal Plain, and Interior Low Plateau.

Back to Sometimes a Great Notion: Visualizing Forest Fragmentation

Adapted from Southern Research Station general technical reports: Human Influences on Forest Ecosystems and The Southern Forest Resource Assessment.