2.9 Corridor Width

Wide corridors, both upland and riparian, provide greater habitat area with reduced edge effects, while generally promoting more opportunities for species movement. Wider riparian corridors can facilitate stream meandering, providing overall higher habitat quality and diversity.

Many studies have examined the issue of corridor width for certain species. However, many of the studies have not tested a significant range of corridor widths to adequately determine optimal corridor widths. In addition, for a given width, corridor effectiveness will vary with corridor length, habitat continuity, habitat quality, and many other factors.

With those limitations in mind, the bar graph on the next page summarizes research on species movement through corridors. The black bar denotes the suggested minimum corridor width while the gray bar indicates the upper end of recommended widths. These ranges should be refined with a biologist.

Based on this research, some general relationships on corridor width can be inferred (see line graphs).

A. The larger the species, the wider the corridor will need to be facilitate movement and to provide potential habitat.

B. As the length of the corridor increases, so should the width. Shorter corridors are more likely to provide increased connectivity than long corridors.

C. A corridor will generally need to be wider in landscapes that provide limited habitat or that are dominated by human use.

D. Corridors that need to function for decades or centuries should be wider. Some functions that require significant time include dispersal for slow-moving organisms, gene flow, and changes to range distribution due to climate change.

DOWNLOAD: 2.9 Guidelines and References (PDF)