No Mow May lawns have higher pollinator richness and abundances: An engaged community provides floral resources for pollinators

Abstract

No Mow May is a community science initiative popularized in recent years that encourages property owners to limit their lawn mowing practices during the month of May. The goal of No Mow May is to provide early season foraging resources for pollinators that emerge in the spring, especially in urban landscapes when few floral resources are available. We worked with the city council of Appleton, Wisconsin, USA. to allow No Mow May to take place in May 2020. Four hundred and thirty-five property owners registered for No Mow May in Appleton. We measured floral and bee richness and abundance in the yards of a subset of homes (N = 20) located near regularly mowed urban parks (N = 15) at the end of the month. We found that homes that participated in No Mow May had more diverse and abundant flora than regularly mowed green spaces throughout the city. No Mow May homes had three times higher bee richness and five times higher bee abundances than frequently mowed greenspaces. Using generalized linear models, we found that the best predictor of bee richness was the size of the designated unmowed area, and the best predictors of bee abundances were the size of the unmowed area as well as floral richness. While our findings cannot conclusively attribute increases in bee abundances and richness to the No Mow May efforts, our data does show that bee pollinators make use of no mow spaces as key floral resources during early spring in the upper midwestern United States. A post-No Mow May survey revealed that the participants were keen to increase native floral resources in their yards, increase native bee nesting habitat, reduce mowing intensities, and limit herbicide, pesticide, and fertilizer applications to their lawns. The No Mow May initiative educated an engaged community on best practices to improve the conservation of urban pollinators in future years.

B.Y.O. Bees: Managing wild bee biodiversity in urban greenspaces

“…This is consistent with a meta-analysis by Winfree et al [ 20 ] who found that habitat fragmentation significantly negatively influenced bee populations, when in systems with little natural habitat remaining. Urban spaces managed for pollinator conservation can alleviate this negative influence, by providing a variety of habitat and floral resources for bees, which is supported by this study and other recent work on urban bee populations [ 57 , 58 ].…”

No‐mow amenity grassland case study: Phenology of floral abundance and nectar resource

“…Similar to prior studies, no‐mow was found to yield greater nectar sugar resource and gamma richness of open flower species compared to standard mowing (cf. Del Toro & Ribbons, 2020; Lerman et al., 2018).…”

“…The decline in pollinator abundance has been attributed, in part, to reduced pollen and nectar resource (Powney et al., 2019). No‐mow has been proven to very effectively increase early season floral abundance and richness in domestic lawns, which in turn support a greater abundance and/or richness of bees (Del Toro & Ribbons, 2020; Lerman et al., 2018; Wastian et al., 2016). Floral abundance has been used as a proxy measure for pollinator resource, but the availability of U.K. wildflower nectar values has since enabled more precise quantification (e.g.…”

Dwarf White Clover Supports Pollinators, Augments Nitrogen in Clover–Turfgrass Lawns, and Suppresses Root-Feeding Grubs in Monoculture but Not in Mixed Swards

“…Urban ecologists are increasingly encouraging the conversion of traditional monoculture turfgrass lawns to more diverse habitats (e.g., [2,37]). Millions of citizens engage in ecological gardening and landscaping to support pollinators [38,39], and there is a growing public acceptance of flowering lawns in community parks [40] and residential yards [41][42][43].…”