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PloS One 2019Bees and the pollination services they deliver are beneficial to both food crop production, and for reproduction of many wild plant species. Bee decline has stimulated...
Bees and the pollination services they deliver are beneficial to both food crop production, and for reproduction of many wild plant species. Bee decline has stimulated widespread interest in assessing hazards and risks to bees from the environment in which they live. While there is increasing knowledge on how the use of broad-spectrum insecticides in agricultural systems may impact bees, little is known about effects of other pesticides (or plant protection products; PPPs) such as herbicides and fungicides, which are used more widely than insecticides at a global scale. We adopted a systematic approach to review existing research on the potential impacts of fungicides and herbicides on bees, with the aim of identifying research approaches and determining knowledge gaps. While acknowledging that herbicide use can affect forage availability for bees, this review focussed on the potential impacts these compounds could have directly on bees themselves. We found that most studies have been carried out in Europe and the USA, and investigated effects on honeybees. Furthermore, certain effects, such as those on mortality, are well represented in the literature in comparison to others, such as sub-lethal effects. More studies have been carried out in the lab than in the field, and the impacts of oral exposure to herbicides and fungicides have been investigated more frequently than contact exposure. We suggest a number of areas for further research to improve the knowledge base on potential effects. This will allow better assessment of risks to bees from herbicides and fungicides, which is important to inform future management decisions around the sustainable use of PPPs.
Topics: Animals; Bees; Fungicides, Industrial; Herbicides; Life Cycle Stages; Research; Species Specificity
PubMed: 31821341
DOI: 10.1371/journal.pone.0225743 -
Global Change Biology Feb 2020Natural hazards are naturally occurring physical events that can impact human welfare both directly and indirectly, via shocks to ecosystems and the services they... (Meta-Analysis)
Meta-Analysis
Natural hazards are naturally occurring physical events that can impact human welfare both directly and indirectly, via shocks to ecosystems and the services they provide. Animal-mediated pollination is critical for sustaining agricultural economies and biodiversity, yet stands to lose both from present exposure to natural hazards, and future climate-driven shifts in their distribution, frequency, and intensity. In contrast to the depth of knowledge available for anthropogenic-related threats, our understanding of how naturally occurring extreme events impact pollinators and pollination has not yet been synthesized. We performed a systematic review and meta-analysis to examine the potential impacts of natural hazards on pollinators and pollination in natural and cultivated systems. From a total of 117 studies (74% of which were observational), we found evidence of community and population-level impacts to plants and pollinators from seven hazard types, including climatological (extreme heat, fire, drought), hydrological (flooding), meteorological (hurricanes), and geophysical (volcanic activity, tsunamis). Plant and pollinator response depended on the type of natural hazard and level of biological organization observed; 19% of cases reported no significant impact, whereas the majority of hazards held consistent negative impacts. However, the effects of fire were mixed, but taxa specific; meta-analysis revealed that bee abundance and species richness tended to increase in response to fire, differing significantly from the mainly negative response of Lepidoptera. Building from this synthesis, we highlight important future directions for pollination-focused natural hazard research, including the need to: (a) advance climate change research beyond static "mean-level" changes by better incorporating "shock" events; (b) identify impacts at higher levels of organization, including ecological networks and co-evolutionary history; and (c) address the notable gap in crop pollination services research-particularly in developing regions of the world. We conclude by discussing implications for safeguarding pollination services in the face of global climate change.
Topics: Animals; Bees; Biodiversity; Climate Change; Ecosystem; Fires; Humans; Pollination
PubMed: 31621147
DOI: 10.1111/gcb.14840 -
Biological Reviews of the Cambridge... Aug 2019Approximately 25 years ago, ecologists became increasingly interested in the question of whether ongoing biodiversity loss matters for the functioning of ecosystems. As...
Approximately 25 years ago, ecologists became increasingly interested in the question of whether ongoing biodiversity loss matters for the functioning of ecosystems. As such, a new ecological subfield on Biodiversity and Ecosystem Functioning (BEF) was born. This subfield was initially dominated by theoretical studies and by experiments in which biodiversity was manipulated, and responses of ecosystem functions such as biomass production, decomposition rates, carbon sequestration, trophic interactions and pollination were assessed. More recently, an increasing number of studies have investigated BEF relationships in non-manipulated ecosystems, but reviews synthesizing our knowledge on the importance of real-world biodiversity are still largely missing. I performed a systematic review in order to assess how biodiversity drives ecosystem functioning in both terrestrial and aquatic, naturally assembled communities, and on how important biodiversity is compared to other factors, including other aspects of community composition and abiotic conditions. The outcomes of 258 published studies, which reported 726 BEF relationships, revealed that in many cases, biodiversity promotes average biomass production and its temporal stability, and pollination success. For decomposition rates and ecosystem multifunctionality, positive effects of biodiversity outnumbered negative effects, but neutral relationships were even more common. Similarly, negative effects of prey biodiversity on pathogen and herbivore damage outnumbered positive effects, but were less common than neutral relationships. Finally, there was no evidence that biodiversity is related to soil carbon storage. Most BEF studies focused on the effects of taxonomic diversity, however, metrics of functional diversity were generally stronger predictors of ecosystem functioning. Furthermore, in most studies, abiotic factors and functional composition (e.g. the presence of a certain functional group) were stronger drivers of ecosystem functioning than biodiversity per se. While experiments suggest that positive biodiversity effects become stronger at larger spatial scales, in naturally assembled communities this idea is too poorly studied to draw general conclusions. In summary, a high biodiversity in naturally assembled communities positively drives various ecosystem functions. At the same time, the strength and direction of these effects vary highly among studies, and factors other than biodiversity can be even more important in driving ecosystem functioning. Thus, to promote those ecosystem functions that underpin human well-being, conservation should not only promote biodiversity per se, but also the abiotic conditions favouring species with suitable trait combinations.
Topics: Animals; Biodiversity; Biomass; Food Chain; Phylogeny; Soil
PubMed: 30724447
DOI: 10.1111/brv.12499 -
Innovation (Abingdon, England) 2018Despite the increased attention, which has been given to the issue of involving knowledge and experts from the social sciences and humanities (SSH) into the products and...
Despite the increased attention, which has been given to the issue of involving knowledge and experts from the social sciences and humanities (SSH) into the products and works of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), little is known on what the expectations towards the involvement of SSH in IPBES actually are. The aim of this paper is to close this gap by identifying the range of possible SSH contributions to IPBES that are expected in the literature, and discuss the inherent challenges of and concrete ways to realize these contributions in the particular institutional setting of IPBES. We address these two points by: , assessing the literature dealing with IPBES and building a typology describing the main ways in which contributions from SSH to IPBES have been conceived between 2006 and 2017. We discuss these expected contributions in light of broader debates on the role of SSH in nature conservation and analyse some of the blind spots and selectivities in the perception of how SSH could substantially contribute to the works of IPBES. Then, , by looking at one particular example, economics and its use in the first thematic assessment on pollinators, pollination and food production, we will concretely illustrate how works in a given discipline could contribute in many different and unprecedented ways to the works of IPBES and help identify paths for enhancing the conservation of biodiversity. , we propose a range of practical recommendations as to how to increase the contribution of SSH in the works of IPBES.
PubMed: 29706803
DOI: 10.1080/13511610.2018.1443799 -
PloS One 2017Managed bees are critical for crop pollination worldwide. As the demand for pollinator-dependent crops increases, so does the use of managed bees. Concern has arisen... (Review)
Review
Managed bees are critical for crop pollination worldwide. As the demand for pollinator-dependent crops increases, so does the use of managed bees. Concern has arisen that managed bees may have unintended negative impacts on native wild bees, which are important pollinators in both agricultural and natural ecosystems. The goal of this study was to synthesize the literature documenting the effects of managed honey bees and bumble bees on wild bees in three areas: (1) competition for floral and nesting resources, (2) indirect effects via changes in plant communities, including the spread of exotic plants and decline of native plants, and (3) transmission of pathogens. The majority of reviewed studies reported negative effects of managed bees, but trends differed across topical areas. Of studies examining competition, results were highly variable with 53% reporting negative effects on wild bees, while 28% reported no effects and 19% reported mixed effects (varying with the bee species or variables examined). Equal numbers of studies examining plant communities reported positive (36%) and negative (36%) effects, with the remainder reporting no or mixed effects. Finally, the majority of studies on pathogen transmission (70%) reported potential negative effects of managed bees on wild bees. However, most studies across all topical areas documented the potential for impact (e.g. reporting the occurrence of competition or pathogens), but did not measure direct effects on wild bee fitness, abundance, or diversity. Furthermore, we found that results varied depending on whether managed bees were in their native or non-native range; managed bees within their native range had lesser competitive effects, but potentially greater effects on wild bees via pathogen transmission. We conclude that while this field has expanded considerably in recent decades, additional research measuring direct, long-term, and population-level effects of managed bees is needed to understand their potential impact on wild bees.
Topics: Animals; Bees; Plants; Pollination
PubMed: 29220412
DOI: 10.1371/journal.pone.0189268 -
Plant Biology (Stuttgart, Germany) Jan 2018We conducted a systematic review of the scientific literature published on plant-pollinator interactions, from both the plant and pollinator perspective, in the Chilean... (Review)
Review
We conducted a systematic review of the scientific literature published on plant-pollinator interactions, from both the plant and pollinator perspective, in the Chilean Mediterranean-type ecosystem (MTE hereafter). Our search identified 69 published papers on 235 native plant species from 62 families. Less than 7.9% of the flowering species inhabiting the Chilean Mediterranean have been studied, and most studies were restricted to only one locality and one reproductive season. The geographic location of the studies differed from a random pattern, showing two well-defined areas where most studies were conducted. Likewise, most studies in the Andes Range were performed above 2000 m a.s.l. The number of species of flower visitor per plant species was low (4.25 ± 0.22), which probably results from the historical and biogeographic isolation of Chile. This literature survey shows that studies relating floral traits with pollinator attraction and plant reproduction are the most frequent topics of research, reaching 37.6% of studies, followed by studies that examine pollination in relation to human impact (16.1%), micro- and macroevolution (14.0%), relationships between pollination and other ecological interactions (10.8%), community and network assessments (11.8%), and effects of abiotic variables on pollination interactions (9.7%). Our review highlights a lack of research on the effects of pollination for anthropogenic land use especially as agricultural practice is one of the most salient features of the Chilean MTE. Future directions to increase our understanding of the role of plant-pollinator relationships for biodiversity maintenance should include: to extend the taxonomic and geographic scope of research, to increase the number of spatial and temporal replicates, to increase the number of studies on pollination networks as they provide estimates of community complexity and putative stability, to develop studies that estimate the importance of pollination for plant demographic parameters and conservation, and to conduct studies that estimate the ecological service provided by Chilean native pollinators for crop yield and sustainable agriculture.
Topics: Animals; Chile; Ecosystem; Insecta; Mediterranean Region; Plants; Pollination
PubMed: 29024390
DOI: 10.1111/plb.12644 -
PloS One 2015It has been suggested that the widespread use of neonicotinoid insecticides threatens bees, but research on this topic has been surrounded by controversy. In order to... (Meta-Analysis)
Meta-Analysis Review
It has been suggested that the widespread use of neonicotinoid insecticides threatens bees, but research on this topic has been surrounded by controversy. In order to synthesize which research approaches have been used to examine the effect of neonicotinoids on bees and to identify knowledge gaps, we systematically reviewed research on this subject that was available on the Web of Science and PubMed in June 2015. Most of the 216 primary research studies were conducted in Europe or North America (82%), involved the neonicotinoid imidacloprid (78%), and concerned the western honey bee Apis mellifera (75%). Thus, little seems to be known about neonicotinoids and bees in areas outside Europe and North America. Furthermore, because there is considerable variation in ecological traits among bee taxa, studies on honey bees are not likely to fully predict impacts of neonicotinoids on other species. Studies on crops were dominated by seed-treated maize, oilseed rape (canola) and sunflower, whereas less is known about potential side effects on bees from the use of other application methods on insect pollinated fruit and vegetable crops, or on lawns and ornamental plants. Laboratory approaches were most common, and we suggest that their capability to infer real-world consequences are improved when combined with information from field studies about realistic exposures to neonicotinoids. Studies using field approaches often examined only bee exposure to neonicotinoids and more field studies are needed that measure impacts of exposure. Most studies measured effects on individual bees. We suggest that effects on the individual bee should be linked to both mechanisms at the sub-individual level and also to the consequences for the colony and wider bee populations. As bees are increasingly facing multiple interacting pressures future research needs to clarify the role of neonicotinoids in relative to other drivers of bee declines.
Topics: Animals; Bees; Crops, Agricultural; Europe; Imidazoles; Insecticides; Neonicotinoids; Nitro Compounds; North America; Research Design; Serial Publications
PubMed: 26313444
DOI: 10.1371/journal.pone.0136928 -
Ecology Letters May 2014Several floral microbes are known to be pathogenic to plants or floral visitors such as pollinators. Despite the ecological and economic importance of pathogens... (Review)
Review
Several floral microbes are known to be pathogenic to plants or floral visitors such as pollinators. Despite the ecological and economic importance of pathogens deposited in flowers, we often lack a basic understanding of how floral traits influence disease transmission. Here, we provide the first systematic review regarding how floral traits attract vectors (for plant pathogens) or hosts (for animal pathogens), mediate disease establishment and evolve under complex interactions with plant mutualists that can be vectors for microbial antagonists. Attraction of floral visitors is influenced by numerous phenological, morphological and chemical traits, and several plant pathogens manipulate floral traits to attract vectors. There is rapidly growing interest in how floral secondary compounds and antimicrobial enzymes influence disease establishment in plant hosts. Similarly, new research suggests that consumption of floral secondary compounds can reduce pathogen loads in animal pollinators. Given recent concerns about pollinator declines caused in part by pathogens, the role of floral traits in mediating pathogen transmission is a key area for further research. We conclude by discussing important implications of floral transmission of pathogens for agriculture, conservation and human health, suggesting promising avenues for future research in both basic and applied biology.
Topics: Animal Diseases; Animals; Bacterial Physiological Phenomena; Disease Vectors; Flowers; Fungi; Plant Diseases; Plant Nectar; Plants
PubMed: 24528408
DOI: 10.1111/ele.12257 -
Ecology Letters Mar 2014The idea of pollination syndromes has been largely discussed but no formal quantitative evaluation has yet been conducted across angiosperms. We present the first... (Meta-Analysis)
Meta-Analysis Review
The idea of pollination syndromes has been largely discussed but no formal quantitative evaluation has yet been conducted across angiosperms. We present the first systematic review of pollination syndromes that quantitatively tests whether the most effective pollinators for a species can be inferred from suites of floral traits for 417 plant species. Our results support the syndrome concept, indicating that convergent floral evolution is driven by adaptation to the most effective pollinator group. The predictability of pollination syndromes is greater in pollinator-dependent species and in plants from tropical regions. Many plant species also have secondary pollinators that generally correspond to the ancestral pollinators documented in evolutionary studies. We discuss the utility and limitations of pollination syndromes and the role of secondary pollinators to understand floral ecology and evolution.
Topics: Adaptation, Biological; Biological Evolution; Flowers; Geography; Magnoliopsida; Phylogeny; Pollination; Species Specificity; Symbiosis
PubMed: 24393294
DOI: 10.1111/ele.12224 -
PloS One 2013As global environmental change accelerates, biodiversity losses can disrupt interspecific interactions. Extinctions of mutualist partners can create "widow" species,... (Review)
Review
BACKGROUND
As global environmental change accelerates, biodiversity losses can disrupt interspecific interactions. Extinctions of mutualist partners can create "widow" species, which may face reduced ecological fitness. Hypothetically, such mutualism disruptions could have cascading effects on biodiversity by causing additional species coextinctions. However, the scope of this problem - the magnitude of biodiversity that may lose mutualist partners and the consequences of these losses - remains unknown.
METHODOLOGY/PRINCIPAL FINDINGS
We conducted a systematic review and synthesis of data from a broad range of sources to estimate the threat posed by vertebrate extinctions to the global biodiversity of vertebrate-dispersed and -pollinated plants. Though enormous research gaps persist, our analysis identified Africa, Asia, the Caribbean, and global oceanic islands as geographic regions at particular risk of disruption of these mutualisms; within these regions, percentages of plant species likely affected range from 2.1-4.5%. Widowed plants are likely to experience reproductive declines of 40-58%, potentially threatening their persistence in the context of other global change stresses.
CONCLUSIONS
Our systematic approach demonstrates that thousands of species may be impacted by disruption in one class of mutualisms, but extinctions will likely disrupt other mutualisms, as well. Although uncertainty is high, there is evidence that mutualism disruption directly threatens significant biodiversity in some geographic regions. Conservation measures with explicit focus on mutualistic functions could be necessary to bolster populations of widowed species and maintain ecosystem functions.
Topics: Africa; Animals; Asia; Biodiversity; Caribbean Region; Extinction, Biological; Magnoliopsida; Oceania; Pollination; Symbiosis; Vertebrates
PubMed: 23840571
DOI: 10.1371/journal.pone.0066993