Preliminary impacts of reduced mowing in highway ROWs on roadside pollinator abundance and habitat quality Kaitlin Stack Whitney, PhD Introduction • Insect pollinator populations are declining worldwide, primarily due to degradation and loss of habitat. • Roadside ROWs can potentially serve as alternative habitats, but they are also disturbed by road traffic and roadside maintenance. • Reduced mowing may result in more quality habitat through increased floral presence for habitat and foraging. (A) Sites Sites were selected using a multivariate cluster analysis to best represent the surrounding land use, geographic distribution, climactic factors, and road attributes (size, speed limit, traffic) of highways across upstate New York. Each site (n=30) had a block design of 2 miles in a control mowing treatment and 2 miles in a modified mowing treatment. Within each, we had 3 sampling locations per treatment and site. At each sampling location, we visited at least twice per year (generally between May and October). During each visit, we conducted multiple monitoring activities that directly measured pollinator abundance, as well as pollinator habitat quality. (B) Mowing Treatments Control treatment areas received the current mowing schedule. Modified treatment areas received reduced mowing; they were not mowed (except for the safety strip) in 2019 and were mowed in 2020 only after a plant-killing frost. . The experiment will continue into 2021, and modified treatment areas will again (like 2019) not be mowed all season (except for the safety strip). This presentation includes only a portion of the data collected and pollinators observed in the project. Data is preliminary, as another year of data will be collected. Project information is not yet approved by NYSDOT. Study Sites Science, Technology & Society Department, College of Liberal Arts Environmental Science Program, College of Science Rochester institute of Technology Correspondence: kxwsbi@rit.edu Acknowledgments This report was funded in part through grant(s) from the Federal Highway Administration and United States Department of Transportation under the State Planning and Research Program, Section 505 of Title 23, U.S. Code provided by the New York State Department of Transportation. The contents of this report do not necessarily reflect the official views or policy of the United States Department of Transportation, the Federal Highway Administration, or the New York State Department of Transportation. This report does not constitute a standard, specification, regulation, product endorsement, or an endorsement of manufacturers. Thank you to all the NYSDOT staff who supported the planning and safety of this project along NYS highways. Thank you to research assistants who helped sample: Alyssa Schoenfeldt, Virginia Aswad, Debmalya Ray Choudhuri,, Shereef Ghoneim, Jacob Horn, Alyssa Juergens, Matthew Madsen, Thuy Huong Vu, Jay Wickard, and Andrew Yoder. Native Bee and Honey Bee Abundance • Methods: We counted wild bee and honeybee abundance on flower blooms along a 75m linear transect (1). We collected this data twice per year in both 2019 and 2020. While a direct measure of pollinator presence and abundance, it is also a measure of habitat quality for pollinating insects. Invasive/Noxious Plant Species Abundance • Methods: We assessed the proportion of invasive and noxious plant species along a 100m vegetation transect using the line intercept method (2). The species included were: common reed (Phragmites australis), Japanese knotweed (Fallopia japonica), purple loosestrife (Lythrum salicaria), poison ivy (Toxicodendron radicans), wild parsnip (Pastinaca sativa), mile-a-minute (Persicaria perfoliata), oriental bittersweet (Celastrus orbiculatus), Poison sumac (Toxicodendron vernix), and Porcelain berry (Ampelopsis glandulosa). We collected this information twice per year both years. ROW Habitat Working Group Scorecard • Methods: We also used the Rights-of-Way as Habitat Work