Contribution of the Cerrado as Habitat for Sunflower Pollinating Bees

Sociobiology ◽  
2020 ◽  
Vol 67 (2) ◽  
pp. 281
Author(s):  
Mayra Layra Santos Almeida ◽  
Gabriel Santos Carvalho ◽  
Júlia Rodrigues Novais ◽  
Danielle Storck Tonon ◽  
Márcio Luiz Oliveira ◽  
...  

Agricultural landscapes sometimes include natural habitats which can support the ecosystem by enhancing the pollination of crops, thus boosting the productivity. This research was conducted between May and July 2017, in the municipality of Tangará da Serra, Mato Grosso, Brazil, to assess the Cerrado from the perspective of it being a crucial habitat to sustain the sunflower-pollinating bees (Helianthus annuus L.). The bees were sampled using entomological nets and pan traps, in specifically marked out plots (20 m x 150 m), in the Cerrado, and in a sunflower crop, at different distances from the Cerrado border. The assessment was done in terms of the composion and species richness, abundance of individuals and the mass (g) of the sunflower chapters exposed and isolated from the floral visitors. While species richness showed no differences between the Cerrado and sunflower crop, a difference was observed for abundance, with more numbers of individuals in the sunflower crop, most likely because of the food source supply. In the sunflower crop, the bee diversity decreased proportionally as the distance from the border increased. The seed mass of the sunfl ower chapters was significantly higher in the flowers open to visitors than in those of the isolated chapters open for visitation. From the results, it was evident that the bees presente in the Cerrado visit the sunflower crop to gather pollen and nectar, and thus assist in cross-pollinating them and raising the productivity.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cheng Gong ◽  
Liangtao Li ◽  
Jan C. Axmarcher ◽  
Zhenrong Yu ◽  
Yunhui Liu

AbstractIn the intensively farmed, homogenous agricultural landscape of the North China Plain, family graveyards form distinct cultural landscape features. In addition to their cultural value, these graveyards represent semi-natural habitat islands whose potential roles in biodiversity conservation and ecological functioning has remained poorly understood. In this study, we investigated plant species richness on 199 family graveyards of different ages and sizes. In accordance with biogeography theory, both overall and insect-pollinated plant species richness increased with area and age of graveyards. Even small graveyards show a strong potential for conserving local plant richness, and a mosaic of both large and small family graveyards could play an important role in the conservation of farmland biodiversity and related ecosystem functions. The launch of agri-environmental measures that conserve and create semi-natural habitats, in turn benefitting agricultural biodiversity and ecological functioning, has proven difficult in China due to the shortage of dispensable arable land. Given the great value of family graveyards as semi-natural habitats reflected in our study, we propose to focus preliminary efforts on conserving these landscape features as existing, widespread and culturally important semi-natural habitat islands. This would represent an effective, complementary policy to a subsequent re-establishment of other semi-natural habitats for the conservation of biodiversity and ecological functioning in agricultural landscapes.


2021 ◽  
Vol 9 ◽  
Author(s):  
Panlong Wu ◽  
Piaopiao Dai ◽  
Meina Wang ◽  
Sijie Feng ◽  
Aruhan Olhnuud ◽  
...  

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.


2013 ◽  
Vol 145 (6) ◽  
pp. 655-667 ◽  
Author(s):  
Amy C. Rutgers-Kelly ◽  
Miriam H. Richards

AbstractTo investigate how bee (Hymenoptera: Apoidea) communities repopulate habitat following severe disturbances, we compared assemblages in new, regenerating landfill sites planted in 2003, recent landfill sites planted in 2000, and control meadows relatively undisturbed for >40 years. All sites were identically sampled using pan traps and sweep netting, from early May to late September 2003, equalising collection effort among sites. In addition, we carried out five-minute aerial net samplings wherever sites contained large patches of wildflowers. We predicted that abundance and diversity of bees would be highest in recent sites and lowest in new sites. This prediction was partially supported: bees were most abundant in recent sites followed by control, then new sites, but species richness was highest (82 species) in recent sites, followed by new sites (67 species), then control (66 species). A randomisation analysis showed that there were more species than expected in new sites and fewer than expected in control sites. Differences in blossom availability likely explain differences in bee abundance and diversity among habitat regeneration levels. Overall, our results suggest that the bee community recolonised newly available sites immediately in the first year and that bee diversity and abundance increased for at least three years, subsequently declining between three and 40 years.


2021 ◽  
Vol 2 ◽  
Author(s):  
Ola Olsson ◽  
Mark V. Brady ◽  
Martin Stjernman ◽  
Henrik G. Smith

Most landscapes are comprised of multiple habitat types differing in the biodiversity they contain. This is certainly true for human modified landscapes, which are often a mix of habitats managed with different intensity, semi-natural habitats and even pristine habitats. To understand fundamental questions of how the composition of such landscapes affects biodiversity conservation, and to evaluate biodiversity consequences of policies that affect the composition of landscapes, there is a need for models able to translate information on biodiversity from individual habitats to landscape-wide predictions. However, this is complicated by species richness not being additive. We constructed a model to help analyze and solve this problem based on two simple assumptions. Firstly, that a habitat can be characterized by the biological community inhabiting it; i.e., which species occur and at what densities. Secondly, that the probability of a species occurring in a particular unit of land is dictated by its average density in the associated habitats, its spatial aggregation, and the size of the land unit. This model leads to a multidimensional species-area relation (one dimension per habitat). If the goal is to maximize species diversity at the landscape scale (γ-diversity), within a fixed area or under a limited budget, the model can be used to find the optimal allocation of the different habitats. In general, the optimal solution depends on the total size of the species pool of the different habitats, but also their similarity (β-diversity). If habitats are complementary (high β), a mix is usually preferred, even if one habitat is poorer (lower α diversity in one habitat). The model lends itself to economic analyses of biodiversity problems, without the need to monetarize biodiversity value, i.e., cost-effectiveness analysis. Land prices and management costs will affect the solution, such that the model can be used to estimate the number of species gained in relation to expenditure on each habitat. We illustrate the utility of the model by applying it to agricultural landscapes in southern Sweden and demonstrate how empirical monitoring data can be used to find the best habitat allocation for biodiversity conservation within and between landscapes.


2021 ◽  
Vol 28 ◽  
pp. 153-166
Author(s):  
Marjaana Toivonen ◽  
Irina Herzon ◽  
Jenni Toikkanen ◽  
Mikko Kuussaari

Uncultivated field margins are important refugia for pollinating insects in agricultural landscapes. However, the spill-over of pollination services from field margins to adjacent crops is poorly understood. This study (i) examined the effects of landscape heterogeneity on pollinator occurrence in permanent field margins and pollinator visitation to adjacent mass-flowering turnip rape (Brassica rapa ssp. oleifera) in boreal agricultural landscapes, and (ii) tested whether pollinator abundance and species richness in field margins predict abundance and species richness of crop visitors. Pollinators visiting the crop were more affected by landscape heterogeneity than pollinators in adjacent margins. Species richness, total abundance, and the abundance of syrphid flies visiting the crop increased with increasing landscape heterogeneity, whereas, in field margins, landscape heterogeneity had little effect on pollinators. In field-dominated homogeneous landscapes, wild pollinators rarely visited the crop even if they occurred in adjacent margins, whereas in heterogeneous landscapes, differences between the two habitats were smaller. Total pollinator abundance and species richness in field margins were poor predictors of pollinator visitation to adjacent crop. However, high abundances of honeybees and bumblebees in margins were related to high numbers of crop visitors from these taxa. Our results suggest that, while uncultivated field margins help pollinators persist in boreal agricultural landscapes, they do not always result in enhanced pollinator visitation to the adjacent crop. More studies quantifying pollination service delivery from semi-natural habitats to crops in different landscape settings will help develop management approaches to support crop pollination. 


Author(s):  
Vivien von Königslöw ◽  
Felix Fornoff ◽  
Alexandra-Maria Klein

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.


2014 ◽  
Vol 147 (4) ◽  
pp. 432-442 ◽  
Author(s):  
Joseph Moisan-DeSerres ◽  
Madeleine Chagnon ◽  
Valérie Fournier

AbstractLowbush blueberry (Vaccinium angustifolium Aiton (Ericaceae)) production is highly dependent on insect pollination to maximise yields. The current losses in honey bee (Apis mellifera Linnaeus (Hymenoptera: Apidae)) colonies pose a serious threat to the blueberry industry, raising interest in alternative pollinators. Abundance and diversity of native pollinators usually decreases with distance from natural habitats. In this study, we evaluated the effects of distance from wooded habitats such as windbreaks and forest borders on the presence of native pollinators in blueberry fields in Lac-St-Jean (Québec, Canada). Four treatments were compared: single-row, double-row, natural windbreaks, and forest borders. Pan-traps were placed at 5, 30, and 60 m from the windbreak or forest border. A total of 3878 native pollinators were collected and 81% were ground-nesting bees. The forest border was the only treatment with higher abundance and species richness on the periphery (5 m) of the field than at further distances, supporting the hypothesis that the presence of pollinators is favoured by habitats potentially offering more abundant and diverse nutritional resources. Our overall results reveal that native pollinators are distributed quite homogeneously in blueberry fields, suggesting that windbreaks are beneficial to native pollinator communities.


Agriculture ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 115 ◽  
Author(s):  
Olivia Kline ◽  
Neelendra K. Joshi

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.


2013 ◽  
Vol 2013 ◽  
pp. 1-38 ◽  
Author(s):  
M. B. Théodore Munyuli

This study was conducted in 2006 in central Uganda to provide baseline data on relationships between bee community variables and local, climatic, landscape and regional drivers affecting bee community abundance and diversity in agricultural landscapes. Bee abundance and species richness increased significantly () with increase in percent cover of semi-natural habitats and the abundance of wild and cultivated floral resources in the landscape. There were strong linear declines () in bee species richness and abundance with cultivation intensity. Bee species richness declined very steeply with forest distance. Bee species richness and abundance were negatively affected by land-use intensity (). Bee species richness and abundance were strongly negatively correlated () with increase in mean annual temperatures in the previous years than in current years indicating potential vulnerability of local bee species to future climate changes. The percent cover of semi-natural habitats and natural in the farmland predicted best the occurrence and distribution in central Uganda. It is therefore recommended to policy-makers and to farmers to invest in the protection of forest fragments (and related semi-natural habitats) acting as buffer in the mitigation of negative effects of climate change on bee biodiversity and pollination services delivery.


Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 305
Author(s):  
Alexandra Siffert ◽  
Fabian Cahenzli ◽  
Patrik Kehrli ◽  
Claudia Daniel ◽  
Virginie Dekumbis ◽  
...  

The invasive Drosophila suzukii feeds and reproduces on various cultivated and wild fruits and moves between agricultural and semi-natural habitats. Hedges in agricultural landscapes play a vital role in the population development of D. suzukii, but also harbor a diverse community of natural enemies. We investigated predation by repeatedly exposing cohorts of D. suzukii pupae between June and October in dry and humid hedges at five different locations in Switzerland. We sampled predator communities and analyzed their gut content for the presence of D. suzukii DNA based on the COI marker. On average, 44% of the exposed pupae were predated. Predation was higher in dry than humid hedges, but did not differ significantly between pupae exposed on the ground or on branches and among sampling periods. Earwigs, spiders, and ants were the dominant predators. Predator communities did not vary significantly between hedge types or sampling periods. DNA of D. suzukii was detected in 3.4% of the earwigs, 1.8% of the spiders, and in one predatory bug (1.6%). While the molecular gut content analysis detected only a small proportion of predators that had fed on D. suzukii, overall predation seemed sufficient to reduce D. suzukii populations, in particular in hedges that provide few host fruit resources.


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