Improving Habitat Quality at the Local and Landscape Scales Increases Wild Bee Assemblages and Associated Pollination Services in Apple Orchards in China

Bees provide key pollination services for a wide range of crops. Accumulating evidence shows the effect of semi-natural habitats at the landscape level and local management practices on bee diversity in fields. However, most of the evidence is derived from studies in North America and Europe. Whether this paradigm is applicable in China, which is characterized by smallholder-dominated agricultural landscapes, has rarely been studied. In this study, we aimed to investigate how bee diversity affected apple production, and how landscape and local variables affected bee diversity and species composition on the Northern China Plain. The results showed that bees significantly increased apple fruit set compared to bagged controls. Wild bee diversity was positively related to apple seed numbers. Higher seed numbers reduced the proportion of deformed apples and thus increased fruit quality. Wild bee abundance was positively correlated with flowering ground cover, and both the abundance and species richness of wild bees were positively affected by the percentage of semi-natural habitats. We conclude that apple quality can benefit from ecological intensification comprising the augmentation of wild bees by semi-natural habitats and flowering ground cover. Future pollination management should therefore reduce the intensification level of management at both the local and landscape scales.

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Identity of mass-flowering crops moderates functional trait composition of pollinator communities

Landscape Ecology ◽

10.1007/s10980-021-01261-3 ◽

2021 ◽

Author(s):

Nicole Beyer ◽

Felix Kirsch ◽

Doreen Gabriel ◽

Catrin Westphal

Keyword(s):

Faba Bean ◽

Management Practices ◽

Functional Trait ◽

Flower Morphology ◽

Landscape Diversity ◽

Floral Resources ◽

Wild Bees ◽

Natural Habitats ◽

Mass Flowering ◽

Wild Bee

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.

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Perceptions of wild bees and farm characteristics associated with the uptake of pollinator-supporting land management practices among Canadian apple growers

Renewable Agriculture and Food Systems ◽

10.1017/s1742170520000344 ◽

2020 ◽

pp. 1-10

Author(s):

Rachel A. Nalepa ◽

Graham Epstein ◽

Jeremy Pittman ◽

Sheila R. Colla

Keyword(s):

Land Management ◽

Management Practices ◽

Descriptive Analysis ◽

Management Strategies ◽

Wild Bees ◽

Pollination Services ◽

Wild Bee ◽

Policies And Programs ◽

Bee Communities ◽

Perceived Costs

Abstract Pollination services are critical for food production. Although domesticated honey bees are important pollinators in agriculture, there is growing interest in supporting naturally occurring wild bees. Diversifying pollination management strategies by encouraging healthy wild bee communities may be especially useful for growers of insect-pollinated crops, such as apples. Although research has identified several land management practices that can enhance local pollinator communities on farms, there are few studies on the factors that influence growers to adopt pollinator-supporting actions on their land. Here, we surveyed 75 Canadian apple growers and used regression models to explore the influence of farm characteristics and perceptions about bees on the likelihood of adopting 15 unique pollinator-supporting practices. We also provide a descriptive analysis of growers' pollination management practices and self-assessed resourcefulness on the ability to improve habitat for wild pollinators on the farm. We found that an increase in three variables: awareness of wild bees, perception of the severity of threats facing wild populations, and the perception of the benefits provided by wild bees is associated with more pollinator-supporting practices on the farm. Overall, growers were less likely to adopt pollinator-friendly practices as the fraction of rented land increased and as the perceived costs of implementing these practices rose. We found ‘low-hanging fruit’ (i.e., pollinator-supporting practices that could be easily and inexpensively implemented) were adopted by less than one-third of growers and that the majority of those surveyed had little to no knowledge on what actions to take if they wanted to improve their farms for wild bees or where to go for that knowledge. Our results suggest that policies and programs that focus on raising grower awareness of wild bees, increasing grower perception of their benefits, and reducing the perceived costs of implementing pollinator-supporting practices may positively affect their uptake. A deeper understanding of grower perceptions will provide essential insight into how growers may contribute to wild pollinator conservation while potentially increasing agricultural production and reducing vulnerability borne of heavy reliance on managed pollinators.

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Pollinator enhancement in agriculture: comparing sown flower strips, hedges and sown hedge herb layers in apple orchards

Biodiversity and Conservation ◽

10.1007/s10531-021-02338-w ◽

2021 ◽

Author(s):

Vivien von Königslöw ◽

Felix Fornoff ◽

Alexandra-Maria Klein

Keyword(s):

Species Richness ◽

Agricultural Landscapes ◽

Floral Resources ◽

Apple Orchards ◽

Wild Bees ◽

Natural Habitats ◽

Flower Visitation ◽

Wild Bee ◽

Pollinator Community ◽

Main Driver

AbstractIn intensive agricultural landscapes semi-natural habitats for pollinators are often limited, although willingness to establish pollinator habitat is increasing among farmers. A common pollinator enhancement measure is to provide flower strips, but existent or improved hedgerows might be more effective. In this study, we compare the effectiveness of three pollinator enhancement measures at edges of conventional apple orchards: (i) perennial flower strips, (ii) existent hedgerows, and (iii) existent hedgerows complemented with a sown herb layer. We used orchard edges without any enhancement as control. The study took place over three consecutive years in Southern Germany. Wild bee abundance and species richness were highest in flower strips followed by improved hedges. Hoverflies were also most abundant in flower strips, but not more species rich than at control sites. Wild bee but not hoverfly community composition differed between control and enhancement sites. The overall pollinator community included only few threatened or specialized species. Flower abundance was the main driver for wild bee diversity, whereas hoverflies were largely unaffected by floral resources. Pollinator enhancement had neither an effect on the abundance or species richness within the orchards nor on apple flower visitation. Perennial flower strips seem most effective to enhance wild bees in intensive agricultural landscapes. Additionally, flower-rich hedgerows should be promoted to complement flower strips by extending the flowering period and to increase connectivity of pollinator habitat in agricultural landscapes.

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Wooded Semi-Natural Habitats Complement Permanent Grasslands in Supporting Wild Bee Diversity in Agricultural Landscapes

Insects ◽

10.3390/insects11110812 ◽

2020 ◽

Vol 11 (11) ◽

pp. 812

Author(s):

Justine Rivers-Moore ◽

Emilie Andrieu ◽

Aude Vialatte ◽

Annie Ouin

Keyword(s):

Selection Index ◽

Interaction Network ◽

Diversity Indices ◽

Forest Edge ◽

Agricultural Landscapes ◽

Wild Bees ◽

Natural Habitats ◽

Wild Bee ◽

Bee Communities ◽

The Impact

Loss of semi-natural habitats (SNH) in agricultural landscapes affects wild bees, often negatively. However, how bee communities respond varies and is still unclear. To date, few studies have used precise descriptors to understand these effects. Our aim was to understand the respective and complementary influences of different wooded and herbaceous habitats on wild bee communities. We selected thirty 500-m radius landscapes on a gradient of a percentage of wooded SNH in south-western France. At each landscape, we sampled wild bees in spring 2016 and plants in spring 2015 and 2016 at the forest edge, in a hedgerow, and in a permanent grassland. Pollen carried by the most abundant bee species was collected and identified. Using beta diversity indices, we showed that wild bee community composition differs between the three SNH types, and especially between herbaceous and wooded SNH. Based on Jacobs’ selection index, we showed that pollen of some plant species recorded in wooded SNH are preferentially selected by wild bees. Studying the impact of the loss of each SNH type on the global bee-pollen interaction network, we found that wooded SNH contributed to its resilience, enabling specific plant–bee interactions. Overall, our results underline the non-negligible contribution of wooded SNH to the diversity of wild bees in agricultural landscapes, and thus the importance of maintaining different types of SNH.

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Mitigating the Effects of Habitat Loss on Solitary Bees in Agricultural Ecosystems

Agriculture ◽

10.3390/agriculture10040115 ◽

2020 ◽

Vol 10 (4) ◽

pp. 115 ◽

Cited By ~ 1

Author(s):

Olivia Kline ◽

Neelendra K. Joshi

Keyword(s):

Habitat Loss ◽

Production Systems ◽

Solitary Bees ◽

Agricultural Landscapes ◽

Wild Bees ◽

Natural Habitats ◽

Floral Diversity ◽

Nesting Sites ◽

Bee Diversity ◽

Foraging Ranges

Solitary bees and other wild pollinators provide an important ecosystem service which can benefit both the agricultural economy and the sustainability of many native ecosystems. Many solitary bees, however, are experiencing decreases in their populations and ranges, resulting in an overall loss of pollinator species richness in many areas. Several interacting factors have been implicated in this decline, including increased pesticide use, climate change, and pathogens, but habitat loss remains one of the primary drivers. The widespread conversion of natural habitats into agricultural landscapes has decreased the availability of adequate nesting sites and floral diversity for many bee species. Large monocultures with intensive production systems often cannot support the populations of wild bees (particularly species with short foraging ranges) necessary to ensure adequate pollination of animal-pollinated crops. Diversifying agricultural landscapes through the incorporation of wildflower plantings, as well as the preservation of remaining natural habitats, may offer a solution, as it has been shown to increase both bee diversity and abundance and the pollination of nearby crops. In this review article, we discuss the various effects of habitat loss on solitary bees and different ways to mitigate such effects in order to conserve bee diversity and populations in agricultural landscapes.

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Wild Bee Toxicity Data for Pesticide Risk Assessments

Data ◽

10.3390/data4030098 ◽

2019 ◽

Vol 4 (3) ◽

pp. 98 ◽

Cited By ~ 2

Author(s):

Kathleen A Lewis ◽

John Tzilivakis

Keyword(s):

Risk Assessment ◽

Dietary Exposure ◽

Risk Assessments ◽

Toxicity Data ◽

Wild Bees ◽

Pollination Services ◽

Wild Bee ◽

Long Time ◽

Pollinating Insects ◽

Regulatory Risk Assessment

Pollination services are vital for agriculture, food security and biodiversity. Although many insect species provide pollination services, honeybees are thought to be the major provider of this service to agriculture. However, the importance of wild bees in this respect should not be overlooked. Whilst regulatory risk assessment processes have, for a long time, included that for pollinators, using honeybees (Apis mellifera) as a protective surrogate, there are concerns that this approach may not be sufficiently adequate particularly because of global declines in pollinating insects. Consequently, risk assessments are now being expanded to include wild bee species such as bumblebees (Bombus spp.) and solitary bees (Osmia spp.). However, toxicity data for these species is scarce and are absent from the main pesticide reference resources. The aim of the study described here was to collate data relating to the acute toxicity of pesticides to wild bee species (both topical and dietary exposure) from published regulatory documents and peer reviewed literature, and to incorporate this into one of the main online resources for pesticide risk assessment data: The Pesticide Properties Database, thus ensuring that the data is maintained and continuously kept up to date. The outcome of this study is a dataset collated from 316 regulatory and peer reviewed articles that contains 178 records covering 120 different pesticides and their variants which includes 142 records for bumblebees and a further 115 records for other wild bee species.

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Wild Bee Visitation Rates Exceed Pollination Thresholds in Commercial Cucurbita Agroecosystems

Journal of Economic Entomology ◽

10.1093/jee/toz295 ◽

2019 ◽

Vol 113 (2) ◽

pp. 562-574 ◽

Cited By ~ 4

Author(s):

C M McGrady ◽

R Troyer ◽

S J Fleischer

Keyword(s):

Management Strategies ◽

Field Size ◽

Bee Pollination ◽

Wild Bees ◽

Temporal And Spatial Variation ◽

Pollination Services ◽

Wild Bee ◽

Visitation Rates ◽

Field Edge ◽

Temporal And Spatial

Abstract Wild bees supply sufficient pollination in Cucurbita agroecosystems in certain settings; however, some growers continue to stock fields with managed pollinators due to uncertainties of temporal and spatial variation on pollination services supplied by wild bees. Here, we evaluate wild bee pollination activity in wholesale, commercial pumpkin fields over 3 yr. We identified 37 species of bees foraging in commercial pumpkin fields. Honey bees (Apis mellifera L. [Hymenoptera: Apidae]), squash bees (Eucera (Peponapis) Say, Dorchin [Hymenoptera: Apidae]), and bumble bees (Bombus spp., primarily B. impatiens Cresson [Hymenoptera: Apidae]) were the most active pollinator taxa, responsible for over 95% of all pollination visits. Preference for female flowers decreased as distance from field edge increased for several bee taxa. Visitation rates from one key pollinator was negatively affected by field size. Visitation rates for multiple taxa exhibited a curvilinear response as the growing season progressed and responded positively to increasing floral density. We synthesized existing literature to estimate minimum ‘pollination thresholds’ per taxa and determined that each of the most active pollinator taxa exceeded these thresholds independently. Under current conditions, renting honey bee hives may be superfluous in this system. These results can aid growers when executing pollination management strategies and further highlights the importance of monitoring and conserving wild pollinator populations.

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Preserving habitat quality at local and landscape scales increases wild bee diversity in intensive farming systems

Agriculture Ecosystems & Environment ◽

10.1016/j.agee.2019.01.012 ◽

2019 ◽

Vol 275 ◽

pp. 73-80 ◽

Cited By ~ 9

Author(s):

Orianne Rollin ◽

Néstor Pérez-Méndez ◽

Vincent Bretagnolle ◽

Mickaël Henry

Keyword(s):

Habitat Quality ◽

Farming Systems ◽

Intensive Farming ◽

Wild Bee ◽

Bee Diversity ◽

Landscape Scales

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Targeting perennial vegetation in agricultural landscapes for enhancing ecosystem services

Renewable Agriculture and Food Systems ◽

10.1017/s1742170512000385 ◽

2013 ◽

Vol 29 (2) ◽

pp. 101-125 ◽

Cited By ~ 103

Author(s):

H. Asbjornsen ◽

V. Hernandez-Santana ◽

M. Liebman ◽

J. Bayala ◽

J. Chen ◽

...

Keyword(s):

Ecosystem Services ◽

Agricultural Landscapes ◽

Management Tool ◽

Past Century ◽

Pollination Services ◽

Goods And Services ◽

Wide Range ◽

Perennial Vegetation ◽

Hydrologic Regulation ◽

Pathogen Populations

AbstractOver the past century, agricultural landscapes worldwide have increasingly been managed for the primary purpose of producing food, while other diverse ecosystem services potentially available from these landscapes have often been undervalued and diminished. The incorporation of relatively small amounts of perennial vegetation in strategic locations within agricultural landscapes dominated by annual crops—or perennialization—creates an opportunity for enhancing the provision of a wide range of goods and services to society, such as water purification, hydrologic regulation, pollination services, control of pest and pathogen populations, diverse food and fuel products, and greater resilience to climate change and extreme disturbances, while at the same time improving the sustainability of food production. This paper synthesizes the current scientific theory and evidence for the role of perennial plants in balancing conservation with agricultural production, focusing on the Midwestern USA as a model system, while also drawing comparisons with other climatically diverse regions of the world. Particular emphasis is given to identifying promising opportunities for advancement and critical gaps in our knowledge related to purposefully integrating perennial vegetation into agroecosystems as a management tool for maximizing multiple benefits to society.

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