Marcellus Shale
3:52 pm
Mon March 25, 2013

Federal Study: Shale Development Fragmenting Allegheny County Forests

Credit The National Map, U.S. Geological Survey

A new study from the U.S. Geological Survey (USGS) delineates how the construction of new roads and pipelines for Marcellus Shale natural gas development and other energy industries can mince up local forests, leading to smaller ecosystems and limiting wildlife.

Using aerial imagery, USGS researchers found that developers laid 140 miles of new roads and eight miles of new pipelines for the sake of 647 Marcellus Shale gas wells drilled in Allegheny County from 2004 to 2010.

Locations of gas well leases for Marcellus Shale and non-Marcellus uses in Pennsylvania.
Credit The National Map, U.S. Geological Survey

In doing so, the developers have subdivided the county's wooded areas, creating 35 new "forest patches" out of larger tracts of woodland. Some species of wildlife cannot or will not live within these smaller patches of "edge forest," preferring instead the wider ranges of so-called "interior forest," according to the study.

"For example, certain birds require interior forest area," said Terry Slonecker, USGS research geographer and lead author of the study. "So when you start to slice and dice the landscape with roads and pipelines, much less interior forest is available for them to exist."

Additionally, the disturbance of land from new developments can cause large amounts of debris and runoff to flow into waterways, damaging water ecosystems and aquatic wildlife.

Though they may be among the largest contributors, Marcellus Shale natural gas companies are not the only developers responsible for this fragmentation. Slonecker said the development of other energy industries like coal, wind and coalbed methane can just as easily subdivide ecosystems.

Most of the forest division caused by energy industry activity took place in the eastern tier of Allegheny County, along the border with Westmoreland County.

The study also examined Susquehanna County in northeastern Pennsylvania, finding similar fragmentation occurring there. The research is the latest in a series by the USGS examining the scope of forest fragmentation due to the rise of Marcellus Shale natural gas extraction and other energy industries.