scholarly journals Taxonomic and functional trait diversity of wild bees in different urban settings

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3051 ◽  
Author(s):  
Étienne Normandin ◽  
Nicolas J. Vereecken ◽  
Christopher M. Buddle ◽  
Valérie Fournier

Urbanization is one of the major anthropogenic processes contributing to local habitat loss and extirpation of numerous species, including wild bees, the most widespread pollinators. Little is known about the mechanisms through which urbanization impacts wild bee communities, or the types of urban green spaces that best promote their conservation in cities. The main objective of this study was to describe and compare wild bee community diversity, structure, and dynamics in two Canadian cities, Montreal and Quebec City. A second objective was to compare functional trait diversity among three habitat types (cemeteries, community gardens and urban parks) within each city. Bees were collected using pan traps and netting on the same 46 sites, multiple times, over the active season in 2012 and 2013. A total of 32,237 specimens were identified, representing 200 species and 6 families, including two new continental records,Hylaeus communisNylander (1852) andAnthidium florentinum(Fabricius, 1775). Despite high community evenness, we found significant abundance of diverse species, including exotic ones. Spatio-temporal analysis showed higher stability in the most urbanized city (Montreal) but low nestedness of species assemblages among the three urban habitats in both cities. Our study demonstrates that cities are home to diverse communities of wild bees, but in turn affect bee community structure and dynamics. We also found that community gardens harbour high levels of functional trait diversity. Urban agriculture therefore contributes substantially to the provision of functionally diverse bee communities and possibly to urban pollination services.

2015 ◽  
Vol 282 (1809) ◽  
pp. 20150299 ◽  
Author(s):  
Mia G. Park ◽  
E. J. Blitzer ◽  
Jason Gibbs ◽  
John E. Losey ◽  
Bryan N. Danforth

Wild bee communities provide underappreciated but critical agricultural pollination services. Given predicted global shortages in pollination services, managing agroecosystems to support thriving wild bee communities is, therefore, central to ensuring sustainable food production. Benefits of natural (including semi-natural) habitat for wild bee abundance and diversity on farms are well documented. By contrast, few studies have examined toxicity of pesticides on wild bees, let alone effects of farm-level pesticide exposure on entire bee communities. Whether beneficial natural areas could mediate effects of harmful pesticides on wild bees is also unknown. Here, we assess the effect of conventional pesticide use on the wild bee community visiting apple ( Malus domestica ) within a gradient of percentage natural area in the landscape. Wild bee community abundance and species richness decreased linearly with increasing pesticide use in orchards one year after application; however, pesticide effects on wild bees were buffered by increasing proportion of natural habitat in the surrounding landscape. A significant contribution of fungicides to observed pesticide effects suggests deleterious properties of a class of pesticides that was, until recently, considered benign to bees. Our results demonstrate extended benefits of natural areas for wild pollinators and highlight the importance of considering the landscape context when weighing up the costs of pest management on crop pollination services.


Insects ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1086
Author(s):  
Rachel A. Brant ◽  
Gerardo R. Camilo

High morphological variation is often associated with species longevity, and it is hypothesized that urban-dwelling species may require more plasticity in functional traits such as body size in order to maximize fitness in heterogeneous environments. There has been published research regarding the functional trait diversity of urban bee pollinators. However, no two cities are identical, so the implementation of multi-city studies is vital. Therefore, we compared body size variation in female Halicus ligatus sweat bees from May–October 2016 from three distinct Midwestern United States cities: Chicago, Detroit, and Saint Louis. Additionally, to elucidate potentially influential environmental factors, we assessed the relationship between temperature and measured body size. We collected bees in community gardens and urban farms and measured their head width and intertegular distance as a proxy for overall body size. We utilized an ANCOVA to determine whether body size variation differed significantly across the three surveyed cities. Results indicated that H. ligatus females in Chicago, Detroit, and Saint Louis had significantly different body size ranges. These findings highlight the importance of intraspecific body size variation and support our prediction that bees from different urban environments will have distinct ranges in body size due to local ecological factors affecting their populations. Additionally, we found a significant influence of temperature, though this is probably not the only important ecological characteristic impacting bee body size. Therefore, we also provided a list of predictions for the future study of specific variables that are likely to impact functional trait diversity in urban bees.


2020 ◽  
Vol 65 (1) ◽  
pp. 39-56 ◽  
Author(s):  
Alexandra Harmon-Threatt

Nest site availability and quality are important for maintaining robust populations and communities of wild bees. However, for most species, nesting traits and nest site conditions are poorly known, limiting both our understanding of basic ecology for bee species and conservation efforts. Additionally, many of the threats commonly associated with reducing bee populations have effects that can extend into nests but are largely unstudied. In general, threats such as habitat disturbances and climate change likely affect nest site availability and nest site conditions, which in turn affect nest initiation, growth, development, and overwintering success of bees. To facilitate a better understanding of how these and other threats may affect nesting bees, in this review, I quantify key nesting traits and environmental conditions and then consider how these traits may intersect with observed and anticipated changes in nesting conditions experienced by wild bees. These data suggest that the effects of common threats to bees through nesting may strongly influence their survival and persistence but are vastly understudied. Increasing research into nesting biology and incorporating nesting information into conservation efforts may help improve conservation of this declining but critical group.


2021 ◽  
Author(s):  
Nicole Beyer ◽  
Felix Kirsch ◽  
Doreen Gabriel ◽  
Catrin Westphal

Abstract Context Pollinator declines and functional homogenization of farmland insect communities have been reported. Mass-flowering crops (MFC) can support pollinators by providing floral resources. Knowledge about how MFC with dissimilar flower morphology affect functional groups and functional trait compositions of wild bee communities is scarce. Objective We investigated how two morphologically different MFC, land cover and local flower cover of semi-natural habitats (SNH) and landscape diversity affect wild bees and their functional traits (body size, tongue length, sociality, foraging preferences). Methods We conducted landscape-level wild bee surveys in SNH of 30 paired study landscapes covering an oilseed rape (OSR) (Brassica napus L.) gradient. In 15 study landscapes faba beans (Vicia faba L.) were grown, paired with respective control landscapes without grain legumes. Results Faba bean cultivation promoted bumblebees (Bombus spp. Latreille), whereas non-Bombus densities were only driven by the local flower cover of SNH. High landscape diversity enhanced wild bee species richness. Faba bean cultivation enhanced the proportions of social wild bees, bees foraging on Fabaceae and slightly of long-tongued bumblebees. Solitary bee proportions increased with high covers of OSR. High local SNH flower covers mitigated changes of mean bee sizes caused by faba bean cultivation. Conclusions Our results show that MFC support specific functional bee groups adapted to their flower morphology and can alter pollinators` functional trait composition. We conclude that management practices need to target the cultivation of functionally diverse crops, combined with high local flower covers of diverse SNH to create heterogeneous landscapes, which sustain diverse pollinator communities.


2015 ◽  
Vol 18 (12) ◽  
pp. 1346-1355 ◽  
Author(s):  
Hélène Deraison ◽  
Isabelle Badenhausser ◽  
Nicolas Loeuille ◽  
Christoph Scherber ◽  
Nicolas Gross

2018 ◽  
Vol 32 (5) ◽  
pp. 1379-1389 ◽  
Author(s):  
Hui Zhang ◽  
Han Y. H. Chen ◽  
Juyu Lian ◽  
Robert John ◽  
Li Ronghua ◽  
...  

2020 ◽  
Vol 287 ◽  
pp. 106691 ◽  
Author(s):  
Carolyn J. Lowry ◽  
Sidney C. Bosworth ◽  
Sarah C. Goslee ◽  
Richard J. Kersbergen ◽  
Fredric W. Pollnac ◽  
...  

2019 ◽  
Vol 64 (5) ◽  
pp. 2140-2151
Author(s):  
Maria Włodarska‐Kowalczuk ◽  
Magnus Aune ◽  
Loïc N. Michel ◽  
Agata Zaborska ◽  
Joanna Legeżyńska

2020 ◽  
Vol 49 (2) ◽  
pp. 502-515 ◽  
Author(s):  
Brianne Du Clos ◽  
Francis A Drummond ◽  
Cynthia S Loftin

Abstract Homogeneous, agriculturally intense landscapes have abundant records of pollinator community research, though similar studies in the forest-dominated, heterogeneous mixed-use landscape that dominates the northeastern United States are sparse. Trends of landscape effects on wild bees are consistent across homogeneous agricultural landscapes, whereas reported studies in the northeastern United States have not found this consistency. Additionally, the role of noncrop habitat in mixed-use landscapes is understudied. We assessed wild bee communities in the mixed-use lowbush blueberry (Vaccinium angustifolium Ait.) production landscape of Maine, United States at 56 sites in eight land cover types across two regional landscapes and analyzed effects of floral resources, landscape pattern, and spatial scale on bee abundance and species richness. Within survey sites, cover types with abundant floral resources, including lowbush blueberry fields and urban areas, promoted wild bee abundance and diversity. Cover types with few floral resources such as coniferous and deciduous/mixed forest reduced bee abundance and species richness. In the surrounding landscape, lowbush blueberry promoted bee abundance and diversity, while emergent wetland and forested land cover strongly decreased these measures. Our analysis of landscape configuration revealed that patch mixing can promote wild bee abundance and diversity; however, this was influenced by strong variation across our study landscape. More surveys at intra-regional scales may lead to better understanding of the influence of mixed-use landscapes on bee communities.


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