The Impacts of Right-of-Way Management on Pollinators

Abstract

A study conducted by Bramble and Byrnes in 1952 on the east coast of the United States initiated interest in right-of-way (ROW) corridors and the impacts of their management on local flora and fauna. With over 50 years of extensive research and data provided on eastern ROW’s, Sonoma State University, in conjunction with Pollinator Partnership and Tree Fund, seeks to establish a western electric transmission ROW research network to investigate how ROW corridors can aid in conservation of native flora and fauna in the area.This collaboration, involving Tree Fund, SMUD, PG&E, Pollinator Partnership, and Sonoma State University works to study impacts of Integrated Vegetation Management to develop the best management practices, plant health, risk assessment, and training of the next generation of foresters. In this particular study, we aim to investigate the effects of ROW’s on pollinators. For the past three years, vegetation beneath right-of-ways has been managed through Integrative Vegetation Management (IVM), which can utilize a combination of chemical, biological, mechanical, and other methods. Vegetation management ensures that a low-growing plant community is established beneath the transmission lines in order to reduce the risk of fire and service obstructions. In addition, these rich shrubby and grassy plant communities can serve as habitats for many species, including native pollinators. Now in the fourth year of study at Fairfield Osborn Preserve, we are beginning to compare and contrast specific mechanical and herbicidal methods.For the past three years, vegetation beneath right-of-ways has been managed through Integrative Vegetation Management (IVM), which can utilize a combination of chemical, biological, mechanical, and other methods. Vegetation management ensures that a low-growing plant community is established beneath the transmission lines in order to reduce the risk of fire and service obstructions. In addition, these rich shrubby and grassy plant communities can serve as habitats for many species, including native pollinators. Now in the fourth year of study at Fairfield Osborn Preserve, we are beginning to compare and contrast specific mechanical and herbicidal methods.

Preliminary data from 2015-2017 suggests that native bees prefer unmanaged areas, and honeybees tend to favor managed ROW habitats as opposed to unmanaged, natural areas at Fairfield Osborn Preserve (FOP). However, this pattern has changed over time. In addition, other areas (such as the American River Parkway, not shown) show that native bees may in fact prefer the ROW because of management of invasive plant species. Each set of pollinator observations will need to be placed in a local ecosystem and climate context for further investigation.

Results

Key Terms: rights-of-way, pollinator, power lines, abundance, floral resources, visitation,