Unconventional gas development facilitates plant invasions

Area of Science:

• Ecology
• Environmental Science
• Botany

Background:

• Natural resource development, including unconventional oil and gas extraction, causes habitat disturbance.
• This disturbance, coupled with the introduction of invasive plant propagules, heightens the risk of plant invasions.
• The ecological impacts of unconventional oil and gas development on plant communities and invasive species spread are not well understood.

Purpose of the Study:

• To assess the spread of invasive plants into edge habitats created by unconventional gas development in Pennsylvania.
• To identify factors influencing the establishment of invasive plants on well pads.
• To inform management strategies for mitigating invasive species in development areas.

Main Methods:

• A structural equation model was employed to analyze direct and indirect factors affecting invasive plant establishment.
• Data collected included propagule pressure on access roads, pre-development road network extent, number of wells per pad, and well pad age.
• 127 well pads in Pennsylvania forests overlaying the Marcellus and Utica shale formations were surveyed.

Main Results:

• Invasive plants were found on 61% of the surveyed well pads.
• Invasive plant presence strongly correlated with local propagule pressure on access roads.
• Indirect factors positively associated with invasive plants included pre-development road density, number of wells per pad, and pad age.

Conclusions:

• Unconventional oil and gas development facilitates invasive plant spread into forest ecosystems.
• Management efforts should prioritize monitoring and control in areas with existing infrastructure and multi-well pads.
• Continued development necessitates robust monitoring of surface ecological impacts, particularly invasive species.