Bee (Hymenoptera: Apoidea) diversity within apple orchards and old fields in the Annapolis Valley, Nova Scotia, Canada

Abstract

Bees are important within terrestrial ecosystems, providing pollination, which facilitates plant reproduction. Agricultural regions are large landscapes containing varying proportions of cropland, natural, and semi-natural habitats. Most bees are not restricted to any of these and move freely throughout, exploiting food and nesting resources in favourable locations. Many factors affect bee diversity, and knowledge of these is crucial for promoting healthy bee communities. The main objectives of this study were to compare diversity and guild structure of bee communities across a range of land disturbance levels within the Annapolis Valley, Nova Scotia, Canada, in habitats ranging from managed apple orchards to old fields. The two habitat extremes differed significantly; intensely managed orchards had significantly lower species richness (∼50%) than observed/estimated in old fields, but orchards with intermediate levels of adjacent natural/semi-natural habitat showed affinities to either extreme depending on the metrics used for estimating species richness. Species assemblages in orchards had lower proportions of several guilds, particularly cavity-nesters, bumble bees, and cleptoparasites, than other habitats. These guilds accounted for over 30% of bees collected in old fields but only 3–10% in orchards, increasing with habitat complexity. The use of guilds for assessing the health of bee communities is discussed.

Forested Landscapes Promote Richness and Abundance of Native Bees (Hymenoptera: Apoidea: Anthophila) in Wisconsin Apple Orchards

“…Our results are in agreement with earlier surveys in apple orchards of North America, which documented great diversity of bees (Sheffield et al 2003;Sheffield et al 2008;Sheffield et al 2012) and of wasps (Sheffield et al 2008;Mates et al 2012). Abundance and diversity of native bees in agricultural systems are positively correlated with proximity and extent of the surrounding habitat (Steffan-Dewenter 2003; Kremen et al 2004;Taki et al 2007;Sobek et al 2009;Hagen & Kraemer 2010).…”

“…Plants benefit by being pollinated, which assures seed formation and sexual reproduction; and in return, the plant provides the pollinator with nectar, pollen and sweet fruits. Pollination has contributed to the evolution of floral diversity, mainly of angiosperms (Cane 2008;Sheffield et al 2012). Thirty five percent of the world's food production (vegetables, fruits, edible oil crops, stimulants, nuts and spices) depends on crop pollination by honey bees, bumblebees and solitary bees (Kraemer & Favi 2005;Klein et al 2007;Gallai et al 2009;Das et al 2011).…”

Proximity to Woodland and Landscape Structure Drives Pollinator Visitation in Apple Orchard Ecosystem

“…These bee species, especially solitary bees, commonly live within natural, or semi-natural vegetation. Cavity-nesting bees have been shown to respond negatively to intense agriculture, presumably in response to loss of nesting habitat availability (Sheffield et al, 2013). The area bees forage is dependent on their nesting site as central-placed foragers.…”

Characterization of wild bee communities in apple and blueberry orchards

“…In the present study, bee species richness was similar for both crops – apple and blueberry ( n = 53 and 51) – and numbers are comparable to other studies investigating wild bees in apple orchards (Russo et al ., ; Blitzer et al ., ) and low‐bush blueberry fields ( Vaccinium angustifolium ) in Maine (Bushmann & Drummond, ), although it was higher than in cranberry fields ( Vaccinium macrocarpon ) in Massachusetts (MacKenzie & Eickwort, ). Here, species diversity in apple, calculated as Simpson's invert (1/D), was similar to apple orchards in Nova Scotia, Canada (Sheffield et al ., ). We found that the blueberry associated bee fauna was more diverse than the apple associated.…”