Natural gas drilling in Pennsylvania’s Marcellus Shale over the next two decades could impact the state’s forests and alter several thousand acres of habitat, The Nature Conservancy said Monday in a study.

A team of scientists spent nearly a year analyzing the Pennsylvania’s energy development and future possible impacts from drilling. According to an analysis of aerial photographs, about 3,500 acres of forest have been cleared and an estimated 8,500 additional acres of habitat degraded because of the energy development in recent years.

“We can no longer protect nature without thinking about energy development,” said Nels Johnson, deputy director of the Conservancy’s Pennsylvania chapter and the study’s lead author.

The study considered the types of energy development most likely to alter Pennsylvania’s landscape: natural gas from the Marcellus Shale formation, wind energy, wood biomass and electric and gas transmission. The report then documented the possible impacts on areas of high conservation value.

In the Marcellus play, “about 1,800 Marcellus natural gas wells have already been drilled in Pennsylvania, and as many as 60,000 more could be developed by 2030 if development trends continue,” the report noted. By the end of this year, 500 wind turbines will be generating energy on the Allegheny Front and Appalachian ridges, and between 750 and 2,900 more could be built by 2030, depending on the state’s renewable energy goals.

Because of the scale of Marcellus Shale development, about 40% of the state’s “largest and most ecologically valuable forest areas” in Pennsylvania could see “serious” impacts from energy development, the authors noted.

For every acre of development in Pennsylvania’s forests, several additional acres of habitat for plants and animals are lost to the noise, light, invasive species and other ecological changes that can accompany remote developments, the report stated. “Forests can be fragmented by roads, gas well pads and turbines, creating more of the forest edges where these impacts occur.”

Audubon Pennsylvania provided data and staff to help The Nature Conservancy produce the report, said Audubon Executive Director Phil Wallis.

Nature Conservancy staff members plan to share their findings with industry leaders, policymakers, community organizations and landowners with the intent of collaborating about the state’s energy future.