Ways to reduce forest fragmentation.

• Position: Shale Development

Forest fragmentation from natural gas development in Pennsylvania is caused by gathering lines, the smaller pipelines that carry extracted natural gas to the main distribution pipes, it has been found by a team of researchers in Carnegie Mellon University's College of Engineering, Pittsburgh, Pa. The scientists report that redirecting the lines so they follow the routes of existing roadways greatly would reduce fragmentation.

Forest fragmentation occurs when the key infrastructure related to Marcellus shale natural gas extraction--specifically the well pads themselves, as well as gathering lines and access roads--cuts through the forest, dividing it into smaller sections. While it may seem at first glance that the well pads, which can require anywhere from three to nine acres of cleared forest land, are the biggest culprit of fragmentation, the team discovered the main cause to be the gathering lines. While gathering lines are buried underground, the surfaces above them, called right of ways, are cleared of all trees, causing almost 19 acres of loss per well pad.

"If something cuts a cleared path through the forest, it could be dividing a species' habitat in half," explains coauthor Leslie Abrahams, a doctoral student in engineering and public policy and civil and environmental engineering. "With flying squirrels, for example, the natural gas infrastructure can create openings in the forest that are too wide for them to glide across...