Forest Fragmentation

Tue, 11/08/2011 - 08:02 -- cadoughe

Forest fragmentation occurs when agriculture, urbanization, roads, or other human development breaks up large, contiguous blocks of forest into smaller isolated patches. Fragmentation can create negative impacts on contiguous forest ecosystems in Western North Carolina.

Forest fragmentation produces a decrease in the forest interior, thus limiting the habitat for many species, including songbirds. The decrease in interior habitat leaves these animals more susceptible to predators and nest robbers. As land becomes more fragmented and habitat is lost or degraded, wildlife is forced to adapt to survive. They may suffer high levels of mortality or displacement from increased traffic on existing and new road systems. Noise and light from development may also drive them from their habitats.

In addition to a loss of wildlife habitat, there is a loss of plant habitat. Much like animals, plants have a unique habitat that is often threatened by fragmentation. When certain sections of the forest are cut and not reforested, the species that make up that forest often do not survive.

Fragmentation also leaves the forest interior more susceptible to non-native invasive species. Invasive plants compete with and replace native plants, reduce plant diversity, and cause other disruptions of ecosystem function. Disease and insects can also be introduced into wildland by nursery plants used in nearby landscaping.

Population Versus Wild Spaces

Population versus wild spaces

In addition to a loss of wildlife habitat, there is a loss of plant habitat. Much like animals, plants have a unique habitat that is often threatened by fragmentation. When certain sections of the forest are cut and not reforested, the species that make up that forest often do not survive. Fragmentation also leaves the forest interior more susceptible to non-native invasive species. Invasive plants compete with and replace native plants, reduce plant diversity, and cause other disruptions of ecosystem function. Disease and insects can also be introduced into wildland by nursery plants used in nearby landscaping.

Forest fragmentation also can impair water and air quality. Impervious surfaces of roads, parking lots, homes, and businesses replace woodland plants, trees, and soils that previously stored carbon dioxide, produced oxygen, absorbed pollutants, and protected against erosion. Increased runoff and the introduction of nonpoint-source pollutants diminish the function and change the character of forest wetlands.

Finally, forest fragmentation has an economic impact. When forests are broken into small parcels, the economy of scale for forest management is lost. Increased costs coupled with fewer opportunities for long-term management and protection lead to mismanagement and under-utilization of forests. Some of the more populated counties in the region are projected to have no privately owned parcels larger than 10 acres by 2070.

The population of Western North Carolina is expected to increase by 22.7 percent from 2010 to 2030. To mitigate potential problems associated with increased forest fragmentation, adaptive forest management activities are needed in the wildland-urban interface. New strategies for managing forests across multiple ownerships and on much smaller scales are required.