Pollinator communities in strawberry crops – variation at multiple spatial scales

Abstract

Predicting potential pollination services of wild bees in crops requires knowledge of their spatial distribution within fields. Field margins can serve as nesting and foraging habitats for wild bees and can be a source of pollinators. Regional differences in pollinator community composition may affect this spill-over of bees. We studied how regional and local differences affect the spatial distribution of wild bee species richness, activity-density and body size in crop fields. We sampled bees both from the field centre and at two different types of semi-natural field margins, grass strips and hedges, in 12 strawberry fields. The fields were distributed over four regions in Northern Europe, representing an almost 1100 km long north-south gradient. Even over this gradient, daytime temperatures during sampling did not differ significantly between regions and did therefore probably not impact bee activity. Bee species richness was higher in field margins compared with field centres independent of field size. However, there was no difference between centre and margin in body-size or activity-density. In contrast, bee activity-density increased towards the southern regions, whereas the mean body size increased towards the north. In conclusion, our study revealed a general pattern across European regions of bee diversity, but not activity-density, declining towards the field interior which suggests that the benefits of functional diversity of pollinators may be difficult to achieve through spill-over effects from margins to crop. We also identified dissimilar regional patterns in bee diversity and activity-density, which should be taken into account in conservation management.

The influence of local and landscape scale on single response traits in bees: A meta-analysis

“…Thus, functional composition in a community is determined by response traits (Ricotta and Moretti, 2011). For bees, the most important pollinator group (Klein et al, 2007), sociality, body size, nest location, nest behaviour and dietary specialization are the primary response traits used to explain community structure in agroecosystems (Rader et al, 2014;Ahrenfeldt et al, 2015;Warzecha et al, 2016), and some empirical studies have focused on mechanistic explanations to determine the influence of distinct environmental predictors on the diversity of these bees according to their response traits (Klein et al, 2003a;Le Feon et al, 2016). The evaluation of which response traits are more likely to explain the loss of species in scenarios, such as intensive farming regimes, can be an important step in promoting mitigation actions (Bartomeus et al, 2017).…”

Generalist solitary ground-nesting bees dominate diversity survey in intensively managed agricultural land

“…Strawberries require many individuals, species and bees of different sizes in order to develop optimally (Chagnon et al, 1989(Chagnon et al, , 1993Klatt et al, 2014). A previous study of pollinators in strawberry fields showed that wild bee species richness was lower in the field middle than closer to field margins (Ahrenfeldt et al, 2015). The current study found that wild bee activity-density and species richness changed during 40 days in spring and early summer which may have had a negative effect on pollination of cultivars flowering in early June and middle June when both…”

“…Farmland represents 66% of the Danish landscape (Statistics Denmark, 2014) which means that in the intensely managed agricultural landscape of Denmark, farming systems and permanent field margins, and the resources they offer, may significantly influence the overall biodiversity. Bumble bee species and numbers have declined in Denmark (Dupont et al, 2011), but although 75% of wild and cultivated plant species require insect pollination (Holm, 1982;Prip et al, 1996), there is little knowledge about wild bees on agricultural land in this country (Ahrenfeldt et al, 2015;Calabuig, 2000;Henriksen & Langer, 2013). The current study helps fill this gap.…”

Jasa penyerbukan serangga pengunjung bunga pada pertanaman stroberi di Ciwidey, Bandung

“…Dengan demikian, pemanfaatan serangga polinator liar bersama lebah piaraan diharapkan dapat meningkatkan hasil panen (Albano et al 2009b;Garibaldi et al 2013). Peningkatan kelimpahan dan pelestarian serangga polinator liar dapat dilakukan melalui penataan agroekosistem, di antaranya dengan menanam berbagai tumbuhan berbunga di sekitar pertanaman (Ahrenfeldt et al 2015;Sutter et al 2017;Ganser et al 2018). Anderson et al (2012) melaporkan proporsi buah dengan bentuk sempurna yang lebih banyak pada pertanaman stroberi organik dibandingkan pada pertanaman konvensional, yang diduga disebabkan oleh kelimpahan dan keanekaragaman serangga polinator yang lebih banyak pada kebun organik.…”