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result(s) for
"Vray, Sarah"
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Drastic shifts in the Belgian bumblebee community over the last century
by
Orianne, Rollin
,
Dendoncker Nicolas
,
Vray, Sarah
in
Bumblebees
,
Climate change
,
Community composition
2020
Bumblebees are undergoing strong declines in Europe caused by habitat loss and fragmentation, agricultural intensification, and climate change. Long-term records are necessary to estimate population trends precisely and to propose appropriate mitigation strategies. Based on an original database of 173,788 specimens from museum collections, scientific monitoring, and opportunistic citizen data from 1810 to 2016, we compared changes in species richness and area of occupancy of Belgian bumblebee species through three time-periods (1910–1930, 1970–1989, and 1990–2016). We also assessed if the observed trends are related to species-specific ecological traits and spatial scales (local, regional and national). Overall, species richness decreased over the last century in Belgium, but some regions retained relatively species-rich communities. A strong shift in community composition occurred. Three species remained among the “top five” in terms of species occurrence (area of occupancy) between the three time-periods (B. pascuorum, B. lapidarius, and B. pratorum), but several species that were once widespread declined drastically (B. muscorum, B. humilis, B. ruderatus, and B. veteranus), while a few species increased their distribution (e.g. B. hypnorum and B. terrestris). Habitat preferences significantly explained the observed trends, with declining species preferring open habitats and increasing species preferring wooded habitats.
Journal Article
Changes in caddisflies community composition and distribution along 60 years timespan monitoring in Luxembourg
2023
In Luxembourg, caddisflies have been systematically collected since the early Sixties. Three periods of exhaustive sampling may be distinguished: the Sixties; 1994 to 2002; and a long period from 2007 to the present time in the frame of the Water Framework Directive. Bearing in mind the uneven sampling procedure across periods, we aim to document changes in community composition and distribution through time including the nature of these changes (e.g. gains and losses of species). We hypothesise different trends of species gains and losses for specialist species in comparison to generalist species. Therefore, we propose a method to identify specialist and generalist species in our dataset. Historical data (1961 to 1968) lack information on precise locations and abundance of specimen collected. Consequently, cell grids of original distribution maps are used to compare caddisfly community assemblages along the three monitoring periods. We assess the changes that occur on presence/absence data in specific groups of species (i.e. cold-adapted, warm-adapted specialists and generalist species). Temporal β-diversity results reveal that survey intervals for each monitoring period are dominated by species losses when the comparison is restricted to cold-adapted species. On the other hand, warm-adapted and generalist species are increasing from the Sixties period when compared to the two next periods (1994–2002 and 2007–2020). However, the comparison of the most recent periods reveals species losses even for the warm-adapted and generalist species. This complex picture of caddisflies species losses and gains in different ways through time, amongst river types and in response to different pressures, is discussed.
Journal Article
A century of temporal stability of genetic diversity in wild bumblebees
2016
Since the 1950s, bumblebee (
Bombus
) species are showing a clear decline worldwide. Although many plausible drivers have been hypothesized, the cause(s) of this phenomenon remain debated. Here, genetic diversity in recent
versus
historical populations of bumblebee species was investigated by selecting four currently restricted and four currently widespread species. Specimens from five locations in Belgium were genotyped at 16 microsatellite loci, comparing historical specimens (1913–1915) with recent ones (2013–2015). Surprisingly, our results showed temporal stability of genetic diversity in the restricted species. Furthermore, both historical and recent populations of restricted species showed a significantly lower genetic diversity than found in populations of co-occurring widespread species. The difference in genetic diversity between species was thus already present before the alleged recent drivers of bumblebee decline could have acted (from the 1950’s). These results suggest that the alleged drivers are not directly linked with the genetic variation of currently declining bumblebee populations. A future sampling in the entire distribution range of these species will infer if the observed link between low genetic diversity and population distribution on the Belgium scale correlates with species decline on a global scale.
Journal Article
A century of local changes in bumblebee communities and landscape composition in Belgium
by
Rasmont, Pierre
,
Vray, Sarah
,
Michez, Denis
in
Agricultural management
,
Bumblebees
,
Climatic conditions
2019
Bumblebees (Bombus spp.) are declining in most parts of Western Europe. Many studies have highlighted the role of agricultural intensification and urbanisation in this decline, and some have also shown the influence of landscape composition on bumblebee populations. However, very few studies have explored bumblebee communities prior to the onset of these major land use changes, and those studies that do are mostly based on low-resolution spatial data. Here, we perform a comparative analysis based on detailed landscape composition and bumblebee occurrence records between the early twentieth century (1910–1930) and the contemporary period (2013–2015) in four localities representative of Belgium. We show that bumblebee assemblages changed drastically over this period, and that the decline in richness was strongest in areas with the greatest increase in urbanization and agricultural intensification. The one locality still retaining a high proportion of grasslands, orchards and woodlands with the smallest overall change in landscape composition still hosts a rich bumblebee fauna, very similar than in the past. We provide recommendations for land use management based on these findings. We also warn about the importance of other factors such as land use intensity, climatic conditions and altitude, which should be included in any future study addressing changes in bumblebee populations related to land use changes.
Journal Article
Loss of pollinator specialization revealed by historical opportunistic data: Insights from network-based analysis
by
Munoz, François
,
This work was supported by the Belgian Science Policy (BR/132/A1/BELBEES; www.belspo.be) (FJ, PR, SV, MD); the European Regional Development Fund and SPW DGO3 (Interreg V fwvl SAPOLL; https://ec.europa.eu and http://environnement.wallonie.be/administration/dgo3.htm) (FJ, PR, MD)
,
European Project: 506675,FP6-SUSTDEV,ALARM
in
Animal biology
,
Bees
,
Biodiversity
2020
We are currently facing a large decline in bee populations worldwide. Who are the winners and losers? Generalist bee species, notably those able to shift their diet to new or alternative floral resources, are expected to be among the least vulnerable to environmental change. However, studies of interactions between bees and plants over large temporal and geographical scales are limited by a lack of historical records. Here, we used a unique opportunistic century-old countrywide database of bee specimens collected on plants to track changes in the plant-bee interaction network over time. In each historical period considered, and using a network-based modularity analysis, we identified some major groups of species interacting more with each other than with other species (i.e. modules). These modules were related to coherent functional groups thanks to an a posteriory trait-based analysis. We then compared over time the ecological specialization of bees in the network by computing their degree of interaction within and between modules. “True” specialist species (or peripheral species) are involved in few interactions both inside and between modules. We found a global loss of specialist species and specialist strategies. This means that bee species observed in each period tended to use more diverse floral resources from different ecological groups over time, highly specialist species tending to enter/leave the network. Considering the role and functional traits of species in the network, combined with a long-term time series, provides a new perspective for the study of species specialization.
Journal Article
Using Image-based AI for insect monitoring and conservation - InsectAI COST Action
by
Gomez-Segura, Alba
,
Kazlauskis, Karolis
,
Martinou, Angeliki
in
autonomous
,
biodiversity
,
camera
2025
The InsectAI COST action will support insect monitoring and conservation at the national and continental scale in order to understand and counteract widespread insect declines. The Action will bring together a critical mass of researchers and stakeholders in image-based insect AI technologies to direct and drive the research agenda, build research capacity across Europe and support innovation and application. There is mounting evidence that populations of insects around the world are in sharp decline. Understanding trends in species and their drivers is key to knowing the size of the challenge, its causes and how to address it. To identify solutions that lead to sustainable biodiversity alongside economic prosperity, insect monitoring should be efficient and provide standardised and frequently updated status indicators to guide conservation actions. The EU Biodiversity Strategy 2030 identifies the critical challenge of delivering standardised information about the state of nature and image-based insect AI can contribute to this. Specifically, the EU Nature Restoration Law will likely set binding targets for the high resolution data that cameras can provide. Thus, outputs of the Action will contribute directly to EU policies implementation, where biodiversity monitoring is considered a key component. The InsectAI COST Action will organise workshops, conferences, short-term scientific missions, hackathons, design-sprints and much more, across four Working Groups. These groups will address how image-based insect AI technologies can best address Societal Needs, support innovation in Image Collection hardware, create standardised approaches for Image Processing and develop novel Data Analysis and Integration methods for turning data into actionable insights.
Journal Article
Divergent geographic patterns of genetic diversity among wild bees: Conservation implications
by
Delangre, Jessica
,
Evolutionary Biology and Ecology [Brussels] ; Université libre de Bruxelles (ULB)
,
Lutte biologique et Ecologie spatiale (LUBIES) ; Université libre de Bruxelles (ULB)-Ecole Interfacultaire de Bioingénieurs
in
Bees
,
Biodiversity
,
BIODIVERSITY RESEARCH
2018
Aim: Genetic diversity is a key factor to species survival. This diversity is unevenly distributed across the species range, delimiting genetic diversity hotspots (GDH). Focusing conservation efforts on regions where GDH of several species overlap (i.e., multispecies GDH) could rationalize conservation efforts by protecting several taxa in one go. However, recent studies suggest the existence of many species-specific GDH. This would make spatially prioritizing protection even more challenging as it requires the integration of these multiple GDH rather than few hotspots into conservation planning. Here, we characterize GDH of nine co-distributed bee species through an original comparative mapping approach to assess the suitability of a spatial prioritization strategy to protect their genetic diversity. Location: We studied bee populations from Europe. Methods: First, we used a sliding window approach to estimate the nucleotide diversity and its geographic distribution to highlight GDH of each species. Second, we assessed the overlap of GDH between species by generating consensus maps based on the species-specific maps of nucleotide diversity. Third, we used the GDH distribution patterns to identify the extent of cost-effective area network that would be needed to protect genetic diversity of all nine species. Results: Genetic diversity was unevenly distributed across species ranges, but we found no evidence of a large overlap among GDH from all species. Cost-effective area network needed to protect genetic diversity of all species spreads over several large geographic areas including regions under high human development pressures. Main conclusions: Genetic diversity hotspots' location is species-specific. Therefore, focusing conservation efforts strictly on the few regions harbouring GDH for many bee species is unlikely to be sufficient to ensure long-term persistence of all species. Conservation actions should be implemented simultaneously in different regions according to a complementary-based conservation approach, to optimize the conservation of all bee diversity.
Journal Article
Multi-decadal improvements in the ecological quality of European rivers are not consistently reflected in biodiversity metrics
Humans impact terrestrial, marine and freshwater ecosystems, yet many broad-scale studies have found no systematic, negative biodiversity changes (for example, decreasing abundance or taxon richness). Here we show that mixed biodiversity responses may arise because community metrics show variable responses to anthropogenic impacts across broad spatial scales. We first quantified temporal trends in anthropogenic impacts for 1,365 riverine invertebrate communities from 23 European countries, based on similarity to least-impacted reference communities. Reference comparisons provide necessary, but often missing, baselines for evaluating whether communities are negatively impacted or have improved (less or more similar, respectively). We then determined whether changing impacts were consistently reflected in metrics of community abundance, taxon richness, evenness and composition. Invertebrate communities improved, that is, became more similar to reference conditions, from 1992 until the 2010s, after which improvements plateaued. Improvements were generally reflected by higher taxon richness, providing evidence that certain community metrics can broadly indicate anthropogenic impacts. However, richness responses were highly variable among sites, and we found no consistent responses in community abundance, evenness or composition. These findings suggest that, without sufficient data and careful metric selection, many common community metrics cannot reliably reflect anthropogenic impacts, helping explain the prevalence of mixed biodiversity trends.
Journal Article
Conditionality of COVID-19 vaccine acceptance in European countries
2022
•Mixed-method survey studied expected COVID vaccine uptake in 7 European countries.•Projected COVID vaccine acceptance by country ranged from 44% to 66%.•Explicit COVID vaccine acceptance or rejection was conditional.•Study finds concerns about vaccine safety and authorities’ competence and honesty.•Study suggests that vaccine conditionality is dynamic, and that safety concerns persist.
The COVID-19 vaccine rollout has offered a powerful preventive measure to help control SARS-CoV-2 transmission. Nevertheless, long-standing public hesitation around vaccines heightened concerns that vaccine coverage would not achieve desired public health impacts, particularly in light of more contagious variants. This cross-sectional survey was conducted online just before the European vaccine rollout in December 2020 among 7000 respondents (aged 18–65) in Belgium, France, Germany, Italy, Spain, Sweden, and Ukraine. The survey included open text boxes for fuller explanation of responses. Overall, 56.9% of respondents would accept a COVID-19 vaccine, 19.0% would not, and 24.1% did not know or preferred not to say. By country, between 44% (France) and 66% (Italy) of respondents would accept a COVID-19 vaccine. Respondents expressed conditionality in open responses, voicing concerns about vaccine safety and mistrust of authorities. We highlight lessons learned about the dynamism of vaccine conditionality and persistence of safety concerns.
Journal Article
HBV immunization and vaccine coverage among hospitalized children in Cameroon, Central African Republic and Senegal: a cross-sectional study
by
Bekondi, Claudine
,
Seck, Abdoulaye
,
Ekobo, Chantal Same
in
Adult
,
Africa - epidemiology
,
Blood
2015
Background
Hepatitis B is a major health concern in Africa. The vaccine against hepatitis B virus (HBV) was introduced into the Expanded Programme on Immunization (EPI) of Cameroon and Senegal in 2005, and of CAR (Central African Republic) in 2008. A cross-sectional study was conducted to assess HBV immunization coverage following the vaccine’s introduction into the EPI and factors associated with having been vaccinated.
Methods
All hospitalized children, regardless of the reasons for their hospitalization, between 3 months and 6 years of age, for whom a blood test was scheduled during their stay and whose condition allowed for an additional 2 mL blood sample to be taken, and who provided the parent’s written consent were included. All children anti-HBs- and anti-HBc + were tested for HBsAg.
Vaccination coverage was assessed in three different ways: immunization card, maternal recall and serologic anti-HBs profile.
Results
1783 children were enrolled between April 2009 and May 2010. An immunization card was only available for 24 % of the children. The median age was 21 months.
Overall HBV immunization coverage based on immunization cards was 99 %, 49 % and 100 % in Cameroon, CAR and Senegal, respectively (
p
< 0,001). The immunization rate based on maternal recall was 91 %, 17 % and 88 % in Cameroon, CAR and Senegal, respectively (
p
< 0,001). According to serology (anti-HBs titer ≥ 10 mUI/mL and anti-HBc-), the coverage rate was 68 %, 13 % and 46 % in Cameroon, CAR and Senegal, respectively (
p
< 0,001). In Senegal and Cameroon, factors associated with having been vaccinated were: mother’s higher education (OR = 2.2; 95 % CI [1.5–3.2]), no malnutrition (OR = 1.6; 95 % CI [1.1–2.2]), access to flushing toilets (OR = 1.6; 95 % CI [1.1–2.3]), and < 24 months old (OR = 2.1; 95 % CI [1.3–3.4] between 12 and 23 months and OR = 2.7; 95 % CI [1.6–4.4] < 12 months). The prevalence of HBV-infected children (HBsAg+) were 0.7 %, 5.1 %, and 0.2 % in Cameroon, CAR and Senegal, respectively (
p
< 0.001).
Conclusions
Assessing immunization coverage based on immunization cards, maternal recall or administrative data could be usefully reinforced by epidemiological data combined with immunological profiles. Serology-based studies should be implemented regularly in African countries, as recommended by the WHO. Malnutrition, lack of maternal education and poverty are factors associated with vaccine non-compliance. The countries’ vaccination programs should actively address these problems.
Journal Article