Roads and Hydrological Impacts in Forested Ecosystems

Roads are widespread throughout forested ecosystems and landscapes across the United States. Recently, people have become more aware of some undesirable changes that roads and vehicles bring to ecosystems. Used for the management of natural resources and recreation, roads are important for economic reasons, but they also result in adverse changes in watershed processes by their presence. One of the greatest impacts of roads is their effect on the hydrology of natural landscapes especially forested ecosystems. Roads can greatly affect the flow of surface and ground water and nutrients. Trails, especially motorized trails, also have the potential to affect hydrology. In this paper, I review the hydrological impacts of roads and trails and develop a rating system to quantitatively rate a particular road or trail.

The linear nature of roads and their tendency to run across topographic gradients have an influence on watershed scale hydrologic processes greater than the land area they occupy. Concentration of runoff from impervious road surfaces and intercepted subsurface flow into ditches effectively increases the drainage density. These hydrologic effects are responsible for changes to geomorphic processes and sediment loads in roaded forest areas (Luce and Wemple 2001).

Wildlands CPR is a non-profit organization that works to protect and restore wildland ecosystems by preventing and removing roads; re-vegetating reclaimed road areas, and limiting motorized recreation (Wildlands CPR). Research on the ecological impacts of roads has been an area of recent study and many aspects of road impacts still need description. Current research provides valuable information to assist in developing a more ecologically sustainable road management system.

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