Diversified Floral Resource Plantings Support Bee Communities after Apple Bloom in Commercial Orchards

Abstract

Natural habitats, comprised of various flowering plant species, provide food and nesting resources for pollinator species and other beneficial arthropods. Loss of such habitats in agricultural regions and in other human-modified landscapes could be a factor in recent bee declines. Artificially established floral plantings may offset these losses. A multi-year, season-long field study was conducted to examine how wildflower plantings near commercial apple orchards influenced bee communities. We examined bee abundance, species richness, diversity, and species assemblages in both the floral plantings and adjoining apple orchards. We also examined bee community subsets, such as known tree fruit pollinators, rare pollinator species, and bees collected during apple bloom. During this study, a total of 138 species of bees were collected, which included 100 species in the floral plantings and 116 species in the apple orchards. Abundance of rare bee species was not significantly different between apple orchards and the floral plantings. During apple bloom, the known tree fruit pollinators were more frequently captured in the orchards than the floral plantings. However, after apple bloom, the abundance of known tree fruit pollinating bees increased significantly in the floral plantings, indicating potential for floral plantings to provide additional food and nesting resources when apple flowers are not available.

Mitigating the Effects of Habitat Loss on Solitary Bees in Agricultural Ecosystems

“…Overall, areas with a higher diversity of flowers, such as natural habitats, have been shown to also have a higher diversity of bees [73,74]. Incorporating diverse floral plantings in an agricultural landscape could enhance ecosystem services of pollinators and other beneficial insects [75,76], and could support bee communities after the flowering period of main crops [77]. The drop in diversity of solitary bees, as they move farther away from these natural habitats, like woods and prairies, is cause for particular concern, because a higher diversity of bee species can have a positive impact on pollination and plant yield.…”

The impact of mass-flowering crops on bee pathogen dynamics

“… Cohen et al (2021) found that pathogen prevalence was diluted instead of amplified for MFC sites that were accompanied by a high non-crop floral abundance. After mass-flowering, the bees that foraged on the MFCs now need to forage on the plants in the surrounding landscape ( González-Varo et al, 2017 ; Heller et al, 2019 ). When the floral abundance is lower here ( Mallinger et al, 2019 ), this may lead to higher floral visitation frequencies and bee densities on these flowers ( González-Varo et al, 2017 ; Benadi et al, 2018 ).…”

Addressing pollination deficits in orchard crops through habitat management for wild pollinators

“…Ground‐nesting bee species nest in areas of undisturbed soil, often south facing with low vegetation cover (Antoine & Forrest, 2021 ; Harmon‐Threatt, 2020 ), such potential nesting areas exist in orchards between vegetated alleyways and at the end of trees rows but the extent to which availability of these habitats constrain populations is not known. Floral resources have been introduced into apple orchards as flowering plants in between apple rows (Campbell et al, 2017 ; McKerchar et al, 2020 ) or adjacent to orchards (Carvell et al, 2021 ; Heller et al, 2019 ) to promote pollinators. Such areas are utilized as a pollen and nectar resource by wild pollinators (Carvell et al, 2021 ; Heller et al, 2019 ), but whether these habitats are sufficient to support populations of important taxa with resulting improved crop pollination and how this is affected by existing landscape context is unknown.…”

“…Floral resources have been introduced into apple orchards as flowering plants in between apple rows (Campbell et al, 2017 ; McKerchar et al, 2020 ) or adjacent to orchards (Carvell et al, 2021 ; Heller et al, 2019 ) to promote pollinators. Such areas are utilized as a pollen and nectar resource by wild pollinators (Carvell et al, 2021 ; Heller et al, 2019 ), but whether these habitats are sufficient to support populations of important taxa with resulting improved crop pollination and how this is affected by existing landscape context is unknown.…”