Title

INFLUENCES OF VEGETATION MANAGEMENT STRATEGIES ON POLLINATOR ASSEMBLAGES ON POWERLINE RIGHTS-OF-WAY

Date of Award

5-3-2018

Semester of Degree

May

Document Type

Open Access Thesis

Major Professor

Melissa Fierke

Steering Committee Member

Christopher Nowak

Steering Committee Member

Scott McArt

Abstract

Pollination carried out by insects is an essential ecosystem function required by 87% of angiosperms and contributing an estimated annual $170 billion in services worldwide. Unfortunately, pollinator populations are declining due to a variety of factors, including introduced pathogens/parasites, pesticide use, and habitat loss/degradation, all of which are caused or facilitated by humans. Powerline rights-of-way (ROWs) have been proposed as conservation/restoration areas as these habitats are able to provide nesting substrates and foraging resources. Field plots were located along powerline ROWs in central New York and in Ohio with explicit goals being to: 1) compare operational vegetation management (IVM) and experimental vegetation management techniques, 2) compare experimental techniques to one another, and 3) compare invasive-exotic plant removal on powerline ROWs by quantifying pollinator parameters (abundance, family richness, diversity, evenness), and describing assemblages to elucidate relationships between pollinators and IE plant prevalence. In New York field plots, management techniques included: tree removal using mechanical means followed by application of herbicide to cut stumps, foliar herbicide application, and brush hog mowing. In Ohio, three management outcomes and their effects on pollinators were evaluated, including tree removal, tree and woody invasive removal, and removal of all woody plants. Throughout the growing season, pollinators were collected with pan traps and sweep netting. Community measures were compared between operational and experimental treatments using paired t-tests and among treatment groups, while relationships among assemblages, treatments, months, and vegetation information were explored using multi-variate analyses. Few treatment effects were observed within community measures, however there were demonstrated differences between pollinator assemblages in operational IVM areas and brush hog mowing areas. Presence of showy honeysuckle, Lonicera bella, and glossy buckthorn, Frangula alnus, was associated with a change in pollinator assemblages and decreased pollinator abundance, richness, and diversity. Curculionidae, Vespidae, Colletidae, and Crabronidae were indicator families in plots where IE species had been removed. Additionally, Halictidae and Hesperidae were associated with disturbance levels associated with treatment methods. In order to further investigate treatment effects, researchers must follow managed areas throughout one full treatment cycle – this would allow determination of treatment half-life and variation in effects throughout the cycle.

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