scholarly journals Phenology and flowering overlap drive specialization in pollinator networks

2020 ◽  
Author(s):  
Paul Glaum ◽  
Thomas J. Wood ◽  
Jonathan R. Morris ◽  
Fernanda S. Valdovinos
Keyword(s):  
Biodiversity Loss ◽  
Diet Breadth ◽  
Floral Resources ◽  
Mechanistic Models ◽  
Wild Bees ◽  
Resource Overlap ◽  
Global Biodiversity ◽  
Plant Pollinator ◽  
Adaptive Foraging ◽  
Temporal Overlap

Variation in diet breadth and specialization stems from fundamental interactions species have with their environment1-3. Consequently, understanding the drivers of this variation is key to understanding ecological and evolutionary processes, and will facilitate the development of predictive tools as ecological networks respond to environmental change4,5. Diet breadth in wild bees has been an area of focus due to both their close mutualistic dependence on plants, and because both groups are under threat from global biodiversity loss6. Though many of the principles governing specialization for pollinators have been identified7,8, they remain largely unvalidated. Using mechanistic models of adaptive foraging in pollinators9,10, we show that while temporal resource overlap has little impact on specialization in pollinators with extended flight periods, reduced overlap increases specialization as pollinator flight periods decrease. These results are corroborated empirically using pollen load data taken from bees with shorter (genus Andrena) and longer (genus Lasioglossum) flight periods across environments with both high and low temporal resource overlap. This approach reveals how interacting phenologies structure plant-pollinator networks and drive pollinator diet breadth via the temporal overlap of floral resources.

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

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.

scholarly journals Above- and belowground biodiversity jointly tighten the P cycle in agricultural grasslands

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yvonne Oelmann ◽  
Markus Lange ◽  
Sophia Leimer ◽  
Christiane Roscher ◽  
Felipe Aburto ◽  
...  
Keyword(s):  
Mycorrhizal Fungi ◽  
Biodiversity Loss ◽  
Management Intensity ◽  
Use Efficiency ◽  
Grassland Productivity ◽  
Global Biodiversity ◽  
Diverse Plant ◽  
Management Effects ◽  
P Cycle

AbstractExperiments showed that biodiversity increases grassland productivity and nutrient exploitation, potentially reducing fertiliser needs. Enhancing biodiversity could improve P-use efficiency of grasslands, which is beneficial given that rock-derived P fertilisers are expected to become scarce in the future. Here, we show in a biodiversity experiment that more diverse plant communities were able to exploit P resources more completely than less diverse ones. In the agricultural grasslands that we studied, management effects either overruled or modified the driving role of plant diversity observed in the biodiversity experiment. Nevertheless, we show that greater above- (plants) and belowground (mycorrhizal fungi) biodiversity contributed to tightening the P cycle in agricultural grasslands, as reduced management intensity and the associated increased biodiversity fostered the exploitation of P resources. Our results demonstrate that promoting a high above- and belowground biodiversity has ecological (biodiversity protection) and economical (fertiliser savings) benefits. Such win-win situations for farmers and biodiversity are crucial to convince farmers of the benefits of biodiversity and thus counteract global biodiversity loss.

scholarly journals Personal Assessment of Reasons for the Loss of Global Biodiversity—an Empirical Analysis

2020 ◽  
Vol 12 (10) ◽  
pp. 4277
Author(s):  
Matthias Winfried Kleespies ◽  
Paul Wilhelm Dierkes
Keyword(s):  
Sustainable Development ◽  
High School Students ◽  
Biodiversity Loss ◽  
Connection To Nature ◽  
School Students ◽  
Teacher Trainees ◽  
Significant Difference ◽  
Global Biodiversity ◽  
The Relationship ◽  
Personal Assessment

The UN's sustainable development goals (SDGs), which aim to solve important economic, social, and environmental problems of humanity, are to be supported by education for sustainable development (ESD). Empirical studies on the success of the implementation of the SDGs in the field of education are still pending. For this reason, using the loss of global biodiversity as an example, this study examined the extent to which high school students, teacher trainees in biology, and biology bachelor students can identify the causes of the global biodiversity loss. A new questioning tool was developed and tested on 889 participants. In addition, the relationship between connection to nature and the personal assessment about biodiversity threats was examined. The factor analysis of the scale used showed that 11 out of 16 items were assigned to the intended factor. The comparison between high school students, teacher trainees in biology, and biology bachelor students showed no significant difference in overall assessment of the reasons for global biodiversity loss. When comparing the three risk levels in which the risk factors for biodiversity could be divided, across the three student groups, only minor differences were found. Therefore, a specific education of prospective teachers is necessary, as they have to pass on the competence as multipliers to their students. No significant difference could be found when examining the relationship between connection to nature and the overall scores of the assessment scale for the reasons of biodiversity loss. However, it was found that people who felt more connected to nature were more capable of assessing the main causes of risk for global biodiversity, while people who felt less connected to nature achieved better scores for the medium factors.

Biodiversity will rise as an international priority

2021 ◽  
Keyword(s):  
Biodiversity Loss ◽  
Political Will ◽  
Content Type ◽  
Biodiversity Crisis ◽  
Low Profile ◽  
Global Biodiversity ◽  
Climate Crisis

Significance No substantive agreements emerged. Global targets to limit biodiversity loss were agreed in 2010, but all were missed and biodiversity loss has accelerated. The 'Kunming Declaration' does indicate some political will, but any enforceable delivery plans will have to wait for the second part of COP15 next year. Impacts The global biodiversity crisis is arguably as serious and pressing as the climate crisis. The low profile of COP15 shows that the severity of the problem is not yet widely recognised. The goal of making 30% of earth's land and seas 'protected' by 2030 provides new focus; disputes will focus on what it actually means. As host, Beijing will want to demonstrate success and will put pressure on other governments. Biodiversity is difficult even to measure, making is extremely challenging to create clear structures for accountable implementation.

scholarly journals Terrestrial Vertebrate Biodiversity Loss under Future Global Land Use Change Scenarios

2018 ◽  
Vol 10 (8) ◽  
pp. 2764 ◽  
Author(s):  
Abhishek Chaudhary ◽  
Arne Mooers
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Low Income ◽  
National Development ◽  
Biodiversity Loss ◽  
Mitigation Measures ◽  
Climate Mitigation ◽  
Meat Production ◽  
Diversity Loss ◽  
Global Biodiversity

Efficient forward-looking mitigation measures are needed to halt the global biodiversity decline. These require spatially explicit scenarios of expected changes in multiple indicators of biodiversity under future socio-economic and environmental conditions. Here, we link six future (2050 and 2100) global gridded maps (0.25° × 0.25° resolution) available from the land use harmonization (LUH) database, representing alternative concentration pathways (RCP) and shared socio-economic pathways (SSPs), with the countryside species–area relationship model to project the future land use change driven rates of species extinctions and phylogenetic diversity loss (in million years) for mammals, birds, and amphibians in each of the 804 terrestrial ecoregions and 176 countries and compare them with the current (1900–2015) and past (850–1900) rates of biodiversity loss. Future land-use changes are projected to commit an additional 209–818 endemic species and 1190–4402 million years of evolutionary history to extinction by 2100 depending upon the scenario. These estimates are driven by land use change only and would likely be higher once the direct effects of climate change on species are included. Among the three taxa, highest diversity loss is projected for amphibians. We found that the most aggressive climate mitigation scenario (RCP2.6 SSP-1), representing a world shifting towards a radically more sustainable path, including increasing crop yields, reduced meat production, and reduced tropical deforestation coupled with high trade, projects the lowest land use change driven global biodiversity loss. The results show that hotspots of future biodiversity loss differ depending upon the scenario, taxon, and metric considered. Future extinctions could potentially be reduced if habitat preservation is incorporated into national development plans, especially for biodiverse, low-income countries such as Indonesia, Madagascar, Tanzania, Philippines, and The Democratic Republic of Congo that are otherwise projected to suffer a high number of land use change driven extinctions under all scenarios.

scholarly journals Habitat Protection Indexes - new monitoring measures for the conservation of coastal and marine habitats

2021 ◽  
Author(s):  
Joy A Kumagai ◽  
Fabio Favoretto ◽  
Sara Pruckner ◽  
Alex David Rogers ◽  
Lauren V Weatherdon ◽  
...  
Keyword(s):  
Biodiversity Loss ◽  
Current Status ◽  
Sustainable Development Goal ◽  
Development Goal ◽  
Habitat Protection ◽  
Marine Habitats ◽  
Freshwater Habitats ◽  
National Jurisdiction ◽  
Global Biodiversity ◽  
Do So

A worldwide call to implement habitat protection aims to halt biodiversity loss. To monitor the extent of coastal and marine habitats within protected areas (PAs) in a standardized, open source, and reproducible way, we constructed the Local and the Global Habitat Protection Indexes (LHPI and GHPI, respectively). The LHPI pinpoints the jurisdictions with the greatest opportunity to expand their own PAs, while the GHPI showcases which jurisdictions contribute the most in area to the protection of these habitats globally. Jurisdictions were evaluated to understand which have the highest opportunity to contribute globally to the protection of habitats by meeting a target of 30% coverage of PAs with Areas Beyond National Jurisdiction (ABNJ) having the greatest opportunity to do so. While we focus on marine and coastal habitats, our workflow can be extended to terrestrial and freshwater habitats. These indexes are useful to monitor aspects of Sustainable Development Goal 14 and the emerging post-2020 Global Biodiversity Framework, to understand the current status of international cooperation on coastal and marine habitats conservation.

scholarly journals Biodiversity can benefit from climate stabilization despite adverse side effects of land-based mitigation

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Haruka Ohashi ◽  
Tomoko Hasegawa ◽  
Akiko Hirata ◽  
Shinichiro Fujimori ◽  
Kiyoshi Takahashi ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Changes ◽  
Biodiversity Loss ◽  
Integrated Assessment Model ◽  
Assessment Model ◽  
Net Benefit ◽  
Model Framework ◽  
Natural Habitats ◽  
Ghg Mitigation ◽  
Global Biodiversity

AbstractLimiting the magnitude of climate change via stringent greenhouse gas (GHG) mitigation is necessary to prevent further biodiversity loss. However, some strategies to mitigate GHG emission involve greater land-based mitigation efforts, which may cause biodiversity loss from land-use changes. Here we estimate how climate and land-based mitigation efforts interact with global biodiversity by using an integrated assessment model framework to project potential habitat for five major taxonomic groups. We find that stringent GHG mitigation can generally bring a net benefit to global biodiversity even if land-based mitigation is adopted. This trend is strengthened in the latter half of this century. In contrast, some regions projected to experience much growth in land-based mitigation efforts (i.e., Europe and Oceania) are expected to suffer biodiversity loss. Our results support the enactment of stringent GHG mitigation policies in terms of biodiversity. To conserve local biodiversity, however, these policies must be carefully designed in conjunction with land-use regulations and societal transformation in order to minimize the conversion of natural habitats.

scholarly journals Effects of Urbanization on Plant–Pollinator Interactions in the Tropics: An Experimental Approach Using Exotic Plants

Insects ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 773
Author(s):  
Marie Zakardjian ◽  
Benoît Geslin ◽  
Valentin Mitran ◽  
Evelyne Franquet ◽  
Hervé Jourdan
Keyword(s):  
Exotic Species ◽  
Plant Communities ◽  
Urban Areas ◽  
Native Species ◽  
New Caledonia ◽  
Land Use Changes ◽  
Exotic Plants ◽  
Exotic Plant ◽  
Wild Bees ◽  
Plant Pollinator

Land-use changes through urbanization and biological invasions both threaten plant-pollinator networks. Urban areas host modified bee communities and are characterized by high proportions of exotic plants. Exotic species, either animals or plants, may compete with native species and disrupt plant–pollinator interactions. These threats are heightened in insular systems of the Southwest Pacific, where the bee fauna is generally poor and ecological networks are simplified. However, the impacts of these factors have seldom been studied in tropical contexts. To explore those questions, we installed experimental exotic plant communities in urban and natural contexts in New Caledonia, a plant diversity hotspot. For four weeks, we observed plant–pollinator interactions between local pollinators and our experimental exotic plant communities. We found a significantly higher foraging activity of exotic wild bees within the city, together with a strong plant–pollinator association between two exotic species. However, contrary to our expectations, the landscape context (urban vs. natural) had no effect on the activity of native bees. These results raise issues concerning how species introduced in plant–pollinator networks will impact the reproductive success of both native and exotic plants. Furthermore, the urban system could act as a springboard for alien species to disperse in natural systems and even invade them, leading to conservation concerns.

scholarly journals Noncrop Habitat Use by Wild Bees (Hymenoptera: Apoidea) in a Mixed-Use Agricultural Landscape

2020 ◽  
Vol 49 (2) ◽  
pp. 502-515 ◽  
Author(s):  
Brianne Du Clos ◽  
Francis A Drummond ◽  
Cynthia S Loftin
Keyword(s):  
United States ◽  
Floral Resources ◽  
Northeastern United States ◽  
Wild Bees ◽  
Wild Bee ◽  
Lowbush Blueberry ◽  
Mixed Use ◽  
Abundance And Diversity ◽  
Bee Communities ◽  
Bee Abundance

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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