Native plants are the bee’s knees: local and landscape predictors of bee richness and abundance in backyard gardens

Abstract

Native plants are the bee's knees: local and landscape predictors of bee richness and abundance in backyard gardens Permalink https://escholarship.org/uc/item/3p3309hdAbstract Urban gardens may support bees by providing resources in otherwise resource-poor environments. However, it is unclear whether urban, backyard gardens with native plants will support more bees than gardens without native plants. We examined backyard gardens in northwestern Ohio to ask: 1) Does bee diversity, abundance, and community composition differ in backyard gardens with and without native plants? 2) What characteristics of backyard gardens and land cover in the surrounding landscape correlate with changes in the bee community? 3) Do bees in backyard gardens respond more strongly to local or landscape factors? We sampled bees with pan trapping, netting, and direct observation. We examined vegetation characteristics and land cover in 500 m, 1 km, and 2 km buffers surrounding each garden. Abundance of all bees, native bees, and cavity-nesting bees (but not ground-nesting bees) was greater in native plant gardens but only richness of cavity-nesting bees differed in gardens with and without native plants. Bee community composition differed in gardens with and without native plants. Overall, bee richness and abundance were positively correlated with local characteristics of backyard gardens, such as increased floral abundance, taller vegetation, more cover by woody plants, less cover by grass, and larger vegetable gardens. Differences in the amount of forest, open space, and wetlands surrounding gardens influenced abundance of cavity-and ground-nesting bees, but at different spatial scales. Thus, presence of native plants, and local and landscape characteristics might play important roles in maintaining bee diversity within urban areas.

Plant diversity and composition compensate for negative effects of urbanization on foraging bumble bees

“…Interestingly, most of the plants visited by bumble bees in this study were native plants, such as T. repens , R. fruticosus , or L. corniculatus (Table SII). This finding agrees with recent studies that suggest native plant species to promote bee abundance in urban gardens (Pawelek et al 2009;Pardee and Philpott 2014).…”

Variability of bumblebee communities (Apidae, Bombini) in urban green areas

“…Other researchers point out that floristic richness is a factor influencing the bumblebees abundance and their species diversity (Widmer and Schmid-Hempel 1999; Steffan- Dewenter et al 2002;Diaz-Ferero et al 2012;Parde and Philipott 2014;Salisbury et al 2015;Wood et al 2015). However, on the Wrocław study sites the number of visited flowering plants did not correlate with the size of the site r = 0.0792 (Fig.…”

Landscape and Local Correlates of Bee Abundance and Species Richness in Urban Gardens

“…In other urban bee studies, declines in local resource availability negatively affect bees (Kearns andOliveras 2009, Matteson andLangellotto 2010). For example, increases in nest site availability and increasing floral abundance and flower patch sizes (of either native or nonnative plants) positively correlate with bee abundance and richness (Gathmann and Tscharntke 2002, Frankie et al 2005, Matteson and Langellotto 2010, Wojcik and McBride 2012, Pardee and Philpott 2014. Important to note in our study is that garden size was positively correlated with the amount of bare ground in 100-by 100-m plots, so any effects of increasing garden size may also be due to increases in the amount of bare ground-an important nesting resource for many bee species.…”

“…These studies all differ in terms of duration and numbers of gardens sampled with those at the lower end (e.g., 34 bees), representing a single garden sampled over many years, and those on the high end (e.g., 80 bees) from studies examining several gardens over several years. Other studies have documented between 54 and 66 species in New York City and Ohio urban gardens (Matteson et al 2008, Pardee andPhilpott 2014). Several studies have examined bees along a rural to urban gradient or in suburban (rather than urban) areas and have typically collected more bee species (58 to > 110 bees), likely because of the greater amount of open space or natural habitat in suburban and rural areas (Fetridge et al 2008, Banaszak-Cibicka and Zmihorski 2011, Bates et al 2011.…”

“…Green spaces within urban areas with significant amounts of vegetation can provide a refuge for species of plants, animals, and microbes (Kong et al 2009, Lin et al 2015. Thus, diversity of vertebrates and invertebrates can be conserved through the maintenance of urban green spaces, including, but not limited to, parks, backyard gardens, and small-scale agricultural systems (McKinney 2002, Pardee andPhilpott 2014). Local characteristics, such as garden size, floral diversity, and vegetation complexity, are important predictors of invertebrate species richness in urban areas (McGeoch and Chown 1997, Frankie et al 2005, Matteson and Langellotto 2010, Lin et al 2015).…”