Strips of prairie vegetation placed within row crops can sustain native bee communities

Abstract

As landscapes have become increasingly dominated by intensive agricultural production, plant diversity has declined steeply along with communities of pollinating insects including bees. Semi-natural habitats, such as field edge meadows and hedgerows, can be maintained to provide a diversity of flowering plants that can increase floral resources required by bees. An additional habitat enhancement practice is that of sowing strips of native prairie vegetation within row-cropped fields. In this study, conducted in Iowa, USA, we found that increases in both the abundance and diversity of floral resources in strips of native prairie vegetation within agricultural production fields greatly and positively influenced the bee community. The benefits to the bee community were important for both common and uncommon species and the effect may be strongest early in the season. Using networks of co-occurrence between plant and bee species, we were able to identify two native prairie plants, Ratibida pinnata and Zizia aurea , as potentially keystone resources that can be used to support native bees. When we evaluated the effect of reconstructed prairie strips on bees in the context of the surrounding landscape, we found that these conservation practices had positive effects on bees in agriculturally-dominated areas and that these effects were detectable in low to high complexity landscapes with 8–69% natural habitat. In landscapes dominated by crops with few pollen and nectar resources the inclusion of native prairie strips can buffer the decline of bees and effectively increase bee abundance and diversity.

Can Native Plants Mitigate Climate-related Forage Dearth for Honey Bees (Hymenoptera: Apidae)?

“…The instructions for these programs allow for the incorporation of a wide-range of native plants suitable for the location. Despite the small size, these reconstructions increase the abundance and diversity of native pollinators ( Schulte et al 2017 , Kordbacheh et al 2020 ) and can improve honey bee health and productivity ( Zhang 2020 ). To address the anticipated hardships that will come with continued changes to the environment, due to climate change, we suggest a more deliberate incorporation of drought-tolerant plants in these habitats.…”

Altering crop management practices to promote pollinators

“…Companion planting with flowering cover crops in intercropping systems is another approach that can sustain pollinator communities within crop production fields (Kordbacheh et al, 2020;Norris et al, 2018). In some instances, intercropping with flowering species does not only attract beneficial insects strictly for pollination services, but, as is the case with alyssum (Lobularia maritima (L.) Desv.)…”

Native vegetation embedded in landscapes dominated by corn and soybean improves honey bee health and productivity

“…These programs create conservation cover that can counter declining biodiversity and enhance ecosystem service delivery (Dainese et al, 2019;Dale et al, 2010;Garibaldi et al, 2017;Johnson et al, 2016;Whittingham, 2011). Reconstructed, native vegetation in agricultural landscapes increases the abundance, diversity, and health of wild pollinators, which can benefit the pollination of crops and non-crop plants (Campbell et al, 2017;Haaland et al, 2011;Kordbacheh et al, 2020;Otto et al, 2018;Ricigliano et al, 2019;Scheper et al, 2014;Thogmartin et al, 2017;Whittingham, 2011). Although there appears to be a historical connection between farmland converted into grassland via CRP and honey bee productivity (Otto et al, 2018;Ricigliano et al, 2019), it is unclear if a conservation practice that embeds reconstructed native vegetation in working lands will improve the health and productivity of the exotic honey bee.…”