College of Agriculture and Natural Resources
Center for Land Use Education and Research

What We're Measuring

Edge Width Explained

Edge width is a concept that attempts to capture the influence of the non-forest feature as it extends into the forest. As you can imagine, this can be fairly complex. A clearing made in the forest for a pasture would have a much different impact on the edge forest than a clearing for a four-lane highway. Research (see references below) has found that the “edge influence” of a clearing will typically extend about 100m (300ft) into the forest. This may increase up to 200m (600ft) for a two lane secondary road, and up to 300m (900ft) for a major highway. Since the Connecticut landscape is composed of numerous types of fragmenting land cover features, we chose to use the more conservative edge width of 100m (300ft).


  • Forman R.T.T. 2000. Estimate of the area affected ecologically by the road system of the United States. Conserv Biol 14: 31–35.
  • Forman R.T.T and R.D. Deblinger. 2000. The ecological road-effect zone of a Massachusetts (USA) suburban highway. Conserv Biol 14: 36–46.
  • Harper, K.A., S.E. MacDonald, P.J. Burton, J. Chen, K.D. Brosofske, S.C. Aunders, E.S. E-uskirchen, D. Roberts, M.S. Jaiteh and P. Esseen. 2000. Edge influence on forest structure and composition in fragmented landscapes. Conserv Biol 14: 36–46.
  • Riitters K.H. and J. D. Wickham. 2003. How far to the nearest road? Front Ecol Environ 1(3):125-129.