Pollination services provided to small and large highbush blueberry fields by wild and managed bees

Abstract

Summary1. Plantings of pollinator-dependent crops vary from large, intensively managed fields to small fields that are managed less intensively, yet there is relatively little information on how pollinator populations and their contribution to crop productivity vary across this gradient. 2. We determined the relative importance of wild bees and managed honey bees Apis mellifera L. for crop pollination in the blueberry Vaccinium corymbosum L. system of Michigan, USA, by comparing bee communities in small, isolated blueberry fields with those in large blueberry fields (stocked with managed honey bee hives) and measuring the difference in yields of open-pollinated and pollinator-excluded clusters of flowers. We combined these assessments to calculate the contribution of bees to crop production in this system. 3. Wild bees were the dominant pollinators in small fields, comprising 58% of flower-visiting bees, whereas 97% of bees in large fields were honey bees. Large fields had four times as many bees visiting flowers than small fields, but only one-tenth as many bumble bees as small fields. 4. Levels of fruit set exceeded 85% in all fields and were similar between field sizes. Berry weight increased with flower exposure to pollinators and was positively correlated with bee abundance.Berry weights from open-pollinated flowers were twice as high in large fields compared with small fields. 5. By combining berry weight increases attributable to honey bees and wild bees in blueberry fields with measurements of the bee community adjusted for pollinator efficiency, we calculated the relative contributions of honey bees and wild bees to pollination of Michigan blueberries. We estimate that wild bees provide 82% of the pollination in small fields but only 12% of the total pollination services across this system, mostly through their secondary role in large fields. 6. Synthesis and applications. Wild bees are the primary pollinators of small blueberry fields, but these insects are at low abundance in large fields, perhaps due to a lack of nesting resources or competition for resources with honey bees. Our findings highlight the dependence of commercial fruit producers on honey bees and suggest that increasing the pollination contribution of other bees, particularly bumble bees, in large fields will require that growers adopt wild bee conservation strategies or stock their fields with managed colonies. Quantifying the contributions of managed and wild pollinating bees across the range of crop production scenarios will help to direct development of integrated crop pollination strategies to minimize the risk of pollination deficits affecting food production.

EFFECT OF POLLINATION MODE ON FRUIT SET IN BLUE HONEYSUCKLE (Lonicera caerulea L.)

“…altaica plants. Similar results were observed in blueberry [Isaacs and Kirk 2010], strawberry [Hortyński et al 1991] and kiwifruit [Sotomayor et al 2010]. The high value of the correlation coefficient between the number of seeds and their weight was observed in strawberry [Kaczmarska et al 2008], between fruit weight and seed weight in white crowberry [Oliveira and Dale 2012] and Sorbus domestica [Miko and Gazo 2004].…”

Fruit Set and Fruit Characteristics of Highbush Blueberries (Vaccinium corymbosum cvs. Bluecrop, Coville, and Northland) in an Open Field and a Rain Shelter

“…Therefore, some cultivars do not set fruit without pollinators (Eck, 1988). Especially, berry weight is reduced without pollinators in all blueberry cultivars (Eck, 1988;Free, 1993;MacKenzie, 1997MacKenzie, , 2009Isaacs and Kirk, 2010). Therefore, pollinating insects play a crucial role in ensuring fruit set and quality of highbush , 1967).…”

Effects of landscape configuration on mapping ecosystem service capacity: a review of evidence and a case study in Scotland

“…Linear elements can greatly reduce runoff (Borin et al 2010) and in the UK the presence of individual trees and shelterbelts increases the infiltration capacity of grazed pastures (Marshall et al 2009). The effect of land cover depends however on the amount of rainfall and diminishes with increasing soil saturation (Lull Pisani et al (2013), Macfadyen and Muller (2013), Veres et al (2013), Bianchi et al (2013), Martin et al (2013), Rusch et al (2013), Mitchell et al (2014), Morandin et al (2014) f Svensson et al (2000), Kells et al (2001), Potts et al (2003), Kremen et al (2004), Bodin et al (2006), Williams and Kremen (2007), Ricketts et al (2008), Winfree et al (2009), Isaacs andKirk (2010), Kennedy et al (2013), Morandin and Kremen (2013), Rollin et al (2013), Bailey et al (2014), Stanley and Stout (2014) g de la Fuente de Val et al (2006), Dramstad et al (2006), Borin et al (2010), Kienast et al (2012), van Zanten et al (2014 h Castelle et al (1994), Bartley et al (2006), Ludwig et al (2007), Bu et al (2008), Lenka et al (2012), Yang et al (2012), Shi et al (2013) and Reinhart 1972;Calder 2007;Acreman and Holden 2013). In mountainous catchments the riparian z...…”