Powerline easements – heavily maintained with brush-mowing and herbicide spraying to reduce overgrown vegetation – are at odds with nature. Despite (or perhaps because of) their high maintenance, these areas can also act to enable species movement in suburban and urban landscapes and increase biodiversity. Similar to road verges and railway systems, as well as new infrastructure like wind turbine lines intended to mitigate climate change, converting land under electrical power lines into native early-successional habitat has the potential to create useful wildlife corridors.
Garfinkel, M., Hosler, S., Whelan, C. and Minor, E. 2022. Powerline corridors can add ecological value to suburban landscapes when not maintained as lawn. Sustainability 14(12): 7113.
Power line easements encompass large tracts of connected landscape, and when managed for wildlife, could provide habitat in both urban and even suburban areas. Suburban areas serve as a semi-natural transition between highly urban spaces and rural landscapes, where residential yards and gardens serve as the only contributing habitat for wildlife living in a matrix of urban development. Suburban green spaces greatly vary and are often small, fragmented, and managed similarly to electrical power line easements.
To determine the ecological benefit electrical power lines provide within the context of developed landscapes, a recent study investigated the biodiversity within power line easement corridors, in various management conditions, compared to the biodiversity of the surrounding suburban landscape of residential yards. The study included 10 study corridors that were managed as either native prairie habitat, old-field, or annually mowed. Plants, insect pollinators, and birds were surveyed at twenty-eight randomly selected sub-sites across the ten corridors. In addition, nearby residential yards were selected for non-prairie corridor comparisons.
Over all study sites, 114 plant species, 60 genera of insect pollinators, and 50 species of birds were identified and a total of 2,713 individual insect pollinators. A total of 2,202 individual birds were recorded.
The surveys show that species richness of plants, birds and pollinators were significantly higher in old-field corridors and prairie corridors compared to mowed corridors and residential comparison sites. This implies that power line corridors can provide valuable ecological habitat to suburban and urban landscapes when managed for wildlife habitat. Interestingly, pollinator species were significantly higher in power line corridors managed to old fields due to the increased floral resources.
These results provide compelling management implications for electrical easement corridors in the context of suburban landscapes. Transmission power lines are often managed by one or only a few stakeholders, which may reduce the challenge of coordinating multiple groups to change management requirements in these areas. More research is still needed to understand how these areas should be managed based on different ecoregions across the country, and the impact management has on providing optimal conditions for the invasion of non-native species. However, power line easements have shown to support biodiversity in areas that were historically native prairie, and could be incorporated into urban and suburban management plans whenever possible to improve local habitat.
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