Complementary Sampling Research Articles

Implementation of complementary methods for bat sampling in a karstic landscape in central–northern Guatemala, Central America

The use of complementary sampling methods for bats is recommended to improve inventories of species. Here we performed direct and indirect sampling in caves, in the main river, and in various forest vegetation covers in a karst landscape in central–northern Guatemala. We determined efficiency and complementarity between methods. Using mist nets and with an effort of 2,670 m²h, we captured 296 individuals of 19 species. Using ultrasonic microphones and after 71 hours of recording, we obtained 1,598 effective files of 16 species/sonotypes. Using a harp trap and after 79 hours of operation, we captured 939 individuals of 12 species. In total, we report 34 species/sonotypes. Regarding the percentage of species richness sampled, according to an extrapolation to double the sampling effort, this varied between 69.8 % and 91.5 %, which we consider satisfactory. The percentages of complementarity between methods were over 70 %, notably high between mist nets and ultrasonic microphones (91 %). To date in Guatemala, inventories have been incomplete, mainly because they are biased by the use of mist nets and the capture of bats of the Phyllostomidae family. Training and implementation of non–extensively used methods such as acoustic detection is needed to improve our knowledge about this taxonomic group and provide fundamental information for conservation strategies. Dataset published through GBIF (DOI: 10.15470/3vcvof). Key words: Harp trap, Karstic caves, Lanquín, Mist nets, Riparian environments, Ultrasonic microphones

The importance of family-based sampling for biobanks.

Biobanks aim to improve our understanding of health and disease by collecting and analysing diverse biological and phenotypic information in large samples. So far, biobanks have largely pursued a population-based sampling strategy, where the individual is the unit of sampling, and familial relatedness occurs sporadically and by chance. This strategy has been remarkably efficient and successful, leading to thousands of scientific discoveries across multiple research domains, and plans for the next wave of biobanks are underway. In this Perspective, we discuss the strengths and limitations of a complementary sampling strategy for future biobanks based on oversampling of close genetic relatives. Such family-based samples facilitate research that clarifies causal relationships between putative risk factors and outcomes, particularly in estimates of genetic effects, because they enable analyses that reduce or eliminate confounding due to familial and demographic factors. Family-based biobank samples would also shed new light on fundamental questions across multiple fields that are often difficult to explore in population-based samples. Despite the potential for higher costs and greater analytical complexity, the many advantages of family-based samples should often outweigh their potential challenges.

A dynamic approach for MR T2-weighted pelvic imaging

T2-weighted 2D fast spin echo sequence serves as the standard sequence in
clinical pelvic MR imaging protocols. However, motion artifacts and blurring caused
by peristalsis present significant challenges. Patient preparation such as administering
antiperistaltic agents is often required before examination to reduce artifacts, which
discomfort the patients. This work introduce a novel dynamic approach for T2
weighted pelvic imaging to address peristalsis-induced motion issue without any patient
preparation.
Approach: A rapid dynamic data acquisition strategy with complementary sampling
trajectory is designed to enable highly undersampled motion-resistant data sampling,
and an unrolling method based on deep equilibrium model is leveraged to reconstruct
images from the dynamic sampled k-space data. Moreover, the fix-point convergence of
the equilibrium model ensures the stability of the reconstruction. The high acceleration
factor in each temporal phase, which is much higher than that in traditional static
imaging, has the potential to effectively freeze pelvic motion, thereby transforming
the imaging problem from conventional motion prevention or removal to motion
reconstruction.
Main results: Experiments on both retrospective and prospective data have
demonstrated the superior performance of the proposed dynamic approach in reducing
motion artifacts and accurately depicting structural details compared to standard static
imaging.
Significance: The proposed dynamic approach effectively captures motion states
through dynamic data acquisition and deep learning-based reconstruction, addressing
motion-related challenges in pelvic imaging.

An update on the wild bee fauna (Hymenoptera, Apoidea, Anthophila) of Serbia

Numerous wild bee (Hymenoptera, Apoidea, Anthophila) species show negative population trends, while the knowledge gaps on their occurrences and distributions prevent adequate conservation actions. The need for continuous updating of species records and reconfirmation of their presence has been recognized, especially in understudied areas. The present study presents the results of bee monitoring at 30 Serbian localities, each surveyed three times during 2023. Two sampling methods were used, the transect walks and the pan traps, resulting in a detection of 232 wild bee species. Among them, 13 species found at 13 localities, represent the first published records from Serbia: Andrena ferox Smith, 1847, A. nana (Kirby, 1802), A. praecox (Scopoli, 1763), A. pusilla Pérez, 1903, A. susterai Alfken, 1914, A. angustior (Kirby,1802), A. curvungula Thomson,1870, A. falsifica Perkins, 1915, Hoplitis mitis (Nylander, 1852), Hylaeus friesei (Alfken, 1904), Melitta melanura (Nylander, 1852), Nomada trapeziformis Schmiedeknecht, 1882, and Osmia uncinata Gerstaecker, 1869. This study contributes to an update of the list of bee species in Serbia, that now counts 744 species, and also provides additional data on European distributions. The new information on Melitta melanura is especially noteworthy, since this species has been assessed as Endangered by the European Red List of Bees due to its small area of occupancy and a severely fragmented distribution. Other important findings include the confirmation of the presence of some wild bee species in Serbia, i.e., 10 species reported as new records within the previous update, and 19 species that were without previously available records from the 21st century. Additionally, the present study indicates the effectiveness of both conducted monitoring techniques, in terms of different recorded species and numbers of specimens. These results lead to the conclusion that corroborates the application of complementary sampling methods as an adequate way to survey bee diversity and abundance.

Bats (Mammalia: Chiroptera) of Ubajara National Park, Ceará, Brazil: a diversity assessment using complementary sampling methods

Bats (Mammalia: Chiroptera) of Ubajara National Park, Ceará, Brazil: a diversity assessment using complementary sampling methods

Accelerated model-based T1, T2* and proton density mapping using a Bayesian approach with automatic hyperparameter estimation.

To achieve automatic hyperparameter estimation for the model-based recovery of quantitative MR maps from undersampled data, we propose a Bayesian formulation that incorporates the signal model and sparse priors among multiple image contrasts. We introduce a novel approximate message passing framework "AMP-PE" that enables the automatic and simultaneous recovery of hyperparameters and quantitative maps. We employed the variable-flip-angle method to acquire multi-echo measurements using gradient echo sequence. We explored undersampling schemes to incorporate complementary sampling patterns across different flip angles and echo times. We further compared AMP-PE with conventional compressed sensing approaches such as the -norm minimization, PICS and other model-based approaches such as GraSP, MOBA. Compared to conventional compressed sensing approaches such as the -norm minimization and PICS, AMP-PE achieved superior reconstruction performance with lower errors in mapping and comparable performance in and proton density mappings. When compared to other model-based approaches including GraSP and MOBA, AMP-PE exhibited greater robustness and outperformed GraSP in reconstruction error. AMP-PE offers faster speed than MOBA. AMP-PE performed better than MOBA at higher sampling rates and worse than MOBA at a lower sampling rate. Notably, AMP-PE eliminates the need for hyperparameter tuning, which is a requisite for all the other approaches. AMP-PE offers the benefits of model-based recovery with the additional key advantage of automatic hyperparameter estimation. It works adeptly in situations where ground-truth is difficult to obtain and in clinical environments where it is desirable to automatically adapt hyperparameters to individual protocol, scanner and patient.

Integrating Mobile and Fixed-Site Black Carbon Measurements to Bridge Spatiotemporal Gaps in Urban Air Quality.

Urban air pollution can vary sharply in space and time. However, few monitoring strategies can concurrently resolve spatial and temporal variation at fine scales. Here, we present a new measurement-driven spatiotemporal modeling approach that transcends the individual limitations of two complementary sampling paradigms: mobile monitoring and fixed-site sensor networks. We develop, validate, and apply this model to predict black carbon (BC) using data from an intensive, 100-day field study in West Oakland, CA. Our spatiotemporal model exploits coherent spatial patterns derived from a multipollutant mobile monitoring campaign to fill spatial gaps in time-complete BC data from a low-cost sensor network. Our model performs well in reconstructing patterns at fine spatial and temporal resolution (30 m, 15 min), demonstrating strong out-of-sample correlations for both mobile (Pearson's R ∼ 0.77) and fixed-site measurements (R ∼ 0.95) while revealing features that are not effectively captured by a single monitoring approach in isolation. The model reveals sharp concentration gradients near major emission sources while capturing their temporal variability, offering valuable insights into pollution sources and dynamics.

NDNet: Spacewise Multiscale Representation Learning via Neighbor Decoupling for Real-Time Driving Scene Parsing.

As a safety-critical application, autonomous driving requires high-quality semantic segmentation and real-time performance for deployment. Existing method commonly suffers from information loss and massive computational burden due to high-resolution input-output and multiscale learning scheme, which runs counter to the real-time requirements. In contrast to channelwise information modeling commonly adopted by modern networks, in this article, we propose a novel real-time driving scene parsing framework named NDNet from a novel perspective of spacewise neighbor decoupling (ND) and neighbor coupling (NC). We first define and implement the reversible operations called ND and NC, which realize lossless resolution conversion for complementary thumbnails sampling and collation to facilitate spatial modeling. Based on ND and NC, we further propose three modules, namely, local capturer and global dependence builder (LCGB), spacewise multiscale feature extractor (SMFE), and high-resolution semantic generator (HSG), which form the whole pipeline of NDNet. The LCGB serves as a stem block to preprocess the large-scale input for fast but lossless resolution reduction and extract initial features with global context. Then the SMFE is used for dense feature extraction and can obtain rich multiscale features in spatial dimension with less computational overhead. As for high-resolution semantic output, the HSG is designed for fast resolution reconstruction and adaptive semantic confusion amending. Experiments show the superiority of the proposed method. NDNet achieves the state-of-the-art performance on the Cityscapes dataset which reports 76.47% mIoU at 240+ frames/s and 78.8% mIoU at 150+ frames/s on the benchmark. Codes are available at https://github.com/LiShuTJ/NDNet.

Efficient 3D cone trajectory design for improved combined angiographic and perfusion imaging using arterial spin labeling.

To improve the spatial resolution and repeatability of a non-contrast MRI technique for simultaneous time resolved 3D angiography and perfusion imaging by developing an efficient 3D cone trajectory design. A novel parameterized 3D cone trajectory design incorporating the 3D golden angle was integrated into 4D combined angiography and perfusion using radial imaging and arterial spin labeling (CAPRIA) to achieve higher spatial resolution and sampling efficiency for both dynamic angiography and perfusion imaging with flexible spatiotemporal resolution. Numerical simulations and physical phantom scanning were used to optimize the cone design. Eight healthy volunteers were scanned to compare the original radial trajectory in 4D CAPRIA with our newly designed cone trajectory. A locally low rank reconstruction method was used to leverage the complementary k-space sampling across time. The improved sampling in the periphery of k-space obtained with the optimized 3D cone trajectory resulted in improved spatial resolution compared with the radial trajectory in phantom scans. Improved vessel sharpness and perfusion visualization were also achieved in vivo. Less dephasing was observed in the angiograms because of the short TE of our cone trajectory and the improved k-space sampling efficiency also resulted in higher repeatability compared to the original radial approach. The proposed 3D cone trajectory combined with 3D golden angle ordering resulted in improved spatial resolution and image quality for both angiography and perfusion imaging and could potentially benefit other applications that require an efficient sampling scheme with flexible spatial and temporal resolution.

The potential of acoustic monitoring of aquatic insects for freshwater assessment.

Aquatic insects are a major indicator used to assess ecological condition in freshwater environments. However, current methods to collect and identify aquatic insects require advanced taxonomic expertise and rely on invasive techniques that lack spatio-temporal replication. Passive acoustic monitoring (PAM) is emerging as a non-invasive complementary sampling method allowing broad spatio-temporal and taxonomic coverage. The application of PAM in freshwater ecosystems has already proved useful, revealing unexpected acoustic diversity produced by fishes, amphibians, submerged aquatic plants, and aquatic insects. However, the identity of species producing sounds remains largely unknown. Among them, aquatic insects appear to be the major contributor to freshwater soundscapes. Here, we estimate the potential number of soniferous aquatic insects worldwide using data from the Global Biodiversity Information Facility. We found that four aquatic insect orders produce sounds totalling over 7000 species. This number is probably underestimated owing to poor knowledge of aquatic insects bioacoustics. We then assess the value of sound producing aquatic insects to evaluate ecological condition and find that they might be useful despite having similar responses in pristine and degraded environments in some cases. Both expert and automated identifications will be necessary to build international reference libraries and to conduct acoustic bioassessment in freshwaters. This article is part of the theme issue 'Towards a toolkit for global insect biodiversity monitoring'.

Assessment of waste workers occupational risk to microbial agents and cytotoxic effects of mixed contaminants present in the air of waste truck cabin and ventilation filters

ABSTRACT Workers in the waste-processing industry are potentially exposed to high concentrations of biological contaminants, leading to respiratory and digestive problems and skin irritations. However, few data on the exposure of waste collection truck (WCT) drivers are available. The goal was to document the microbial risk of the waste collection truck (WCT) workers while in the vehicle cab. Long-period sampling using the truck air filters (CAF) and short time ambient air sampling in the cab were used. The potential release of microbial particles from CAFs was also investigated since it could contribute to the microbial load of the cabin air. A combination of analytical methods also helped assess the complex mixture of the biological agents. Aspergillus sections Fumigati and Flavi, E. coli, Enterobacter spp. and Legionella spp. were detected in the CAF of trucks collecting three types of waste. The highest levels of bacteria and fungi were found in the CAF from organic WCT. The highest endotoxin concentrations in CAF were 300 EU/cm2. Most of the CAF showed cytotoxic effects on both lung cells and hepatocytes. Only one mycotoxin was detected in a CAF. The maximal concentrations in the ambient WCT air varied according to the type of waste collected. The highest proportion (84%) of the air samples without cytotoxic effects on the lungs cells was for the recyclable material WCTs. The results revealed the potential microbial risk to workers from a complex mixture of bio-contaminants in the cabs of vehicles collecting all types of waste. The sustained cytotoxic effect indicates the potential adverse health-related impact of mixed contaminants (biological and non-biological) for the workers. Overall, this study highlights the benefits of using complementary sampling strategy and combined analytical methods for a the assessment of the microbial risk in work environments and the need to implement protective measures for the workers. Implications: Exposure to microbial agents is a well-known occupational hazard in the waste management sector. No previous study had evaluated the cytotoxicity of ambient air and ventilation filters to document worker exposure to a combination of contaminants during waste collection. This research confirms the usefulness of ventilation filters for long-term characterization of exposure to infectious agents, azole-resistant fungi, coliform bacteria and mycotoxin. Overall, this study highlights the importance of using several sampling and analysis methods for a comprehensive assessment of microbial risk in work environments, as well as the need to implement appropriate protective measures for collection workers.

Storms mobilize organophosphate esters, bisphenols, PFASs, and vehicle-derived contaminants to San Francisco Bay watersheds.

In urban to peri-urban watersheds such as those surrounding San Francisco Bay, stormwater runoff is a major pathway by which contaminants enter aquatic ecosystems. We evaluated the occurrence of 154 organic contaminants via liquid chromatography coupled to tandem mass spectrometry, including organophosphate esters (OPEs), bisphenols, per- and polyfluoroalkyl substances (PFASs), and a suite of novel urban stormwater tracers (SWCECs; i.e., vehicle-derived chemicals, pesticides, pharmaceuticals/personal care products, benzothiazoles/benzotriazoles). Time-averaged composite sampling focused on storms in highly developed watersheds over four wet seasons, with complementary sampling in less-urban reference watersheds, near-shore estuarine sites, and the open Bay. Of the targeted contaminants, 68 (21 SWCECs, 29 OPEs, 3 bisphenols, 15 PFASs) were detected in ≥10 of 26 urban stormwater samples. Median concentrations exceeded 500 ng L-1 for 1,3-diphenylguanidine, hexa(methoxymethyl)melamine, and caffeine, and exceeded 300 ng L-1 for 2-hydroxy-benzothiazole, 5-methyl-1H-benzotriazole, pentachlorophenol, and tris(2-butoxyethyl) phosphate. Median individual PFAS concentrations were <10 ng L-1, with highest concentrations for PFHxA (180 ng L-1), PFOA (110 ng L-1), and PFOS (81 ng L-1). In six of eight urban stormwater samples analyzed for 6PPD-quinone (a tire rubber-derived transformation product), concentrations exceeded coho salmon acute toxicity thresholds, suggesting (sub)lethal impacts for sensitive species. Observed concentrations were generally significantly higher in highly developed watersheds relative to reference watersheds, but not statistically different in near-shore estuarine sites, suggesting substantial transient exposure potential at stormwater outfalls or creek outflows. Results emphasized the role of stormwater in contaminant transport, the importance of vehicles/roadways as contaminant sources, and the value of monitoring broad multi-analyte contaminant suites to enable comprehensive source and toxicity evaluations.

Exploring the Representation of Women in Technical Roles at a South African Performing Arts Entity

Low levels of female representation are found when it comes to technical roles within the South African performing arts industry despite improved numbers in the overall representation of females within the industry across different occupational categories. Employment in the core functions of the performing arts entities is therefore still predominantly male. The research aimed to explore the representation of women in a performing arts entity. The feminist, social dominance and patriarchy theories were used to conceptualize the research phenomena and interrogate the findings in this study. The research adopted a qualitative case study approach, using one-on-one in-depth interviews. The sample of participants included management and employees in the technical business unit, selected through convenience sampling and a complementary snowball sampling technique. Thematic analysis was used to analyse the data, which engendered themes and sub-themes, substantiated by verbatim quotes from the interviews. Although the research findings indicated an unequal representation of females in technical roles and their absence in management positions within the entity, female presence was found to enhance teamwork and diverse views, which consequently improved team performance. The study found that barriers to female representation include unequal gender representation, the nature of work, and the work-life balance. The study established policy recommendations for the industry, including flexible-hour strategies and childcare facilities, among others.

Taxonomic and Functional Diversity of Bees in Traditional Agroecosystems and Tropical Forest Patches on the Yucatan Peninsula

Background and Research Objectives: Habitat matrices of intensive agricultural use are generally inhospitable to native bees in fragmented forests. However, in some tropical regions of the world, agricultural landscapes are dominated by traditional agroecosystems, which harbor high plant diversity and are subject to low-intensity management. These agroecosystems can therefore provide suitable habitats and important floral resources for the bee community. The objective of this study was to compare the taxonomic and functional diversity of bees in traditional agroecosystems and forest patches within an agricultural landscape of the Yucatan Peninsula. Methods: Sampling was conducted in two traditional agroecosystems (homegardens and a rainfed polyculture known as milpa) and forest patches as a control (N= 24 sites in total. Hereafter: habitats), using two complementary sampling techniques: pan traps and a sweep net. Taxonomic and functional diversity metrics were calculated and compared among habitats. Results: The three habitats were generally similar in terms of taxonomic and functional diversity. Differences were only detected among habitats in the inverse of Simpson’s diversity index and number of functional groups (functional entities), with higher values in the agroecosystems than in the forest. Conclusion: Taxonomic and functional diversity was similar in the traditional agroecosystems and forest patches, suggesting that these agroecosystems can provide temporal adequate resources for most bee functional groups and that movement of bees is possible among these habitats. Conservation Implications: Maintenance of low-intensity management practices and high (agro)biodiversity found in traditional agroecosystems is crucial for the conservation of native bees. It is therefore important to incorporate these systems into management strategies at the landscape level. Since traditional agroecosystems and forests have different land tenure systems (government, private, and communal), conservation strategies at this level require the involvement of different sectors of society.

Pesticide occurrence in a subtropical estuary, Australia: Complementary sampling methods

Monitoring pesticide run-off in the aquatic environment is ecologically important. Effective methods are required to detect the wide range of possible pesticides that enter estuaries from the surrounding catchment. Here, we investigate the occurrence of pesticides in the Richmond River estuary, Australia, and compare the effectiveness of using oysters and Chemcatcher® passive sampling devices against composite water samples. Samples were collected from six sites during two sampling periods: from January to March 2020 (4 weekly composite water samples and oyster collections) and from February to March 2021 (8 twice weekly composite water samples and Chemcatcher® deployment). Samples were analysed for up to 174 pesticides. A total of 21 pesticides were detected across all sites using all methods. The number of pesticides and mixture of pesticides detected in the 2020 sampling was higher in oyster samples than in water samples. In 2021, Chemcatcher® samplers detected more pesticides than in water samples. Herbicides were the most common in all samples. Insecticides and most fungicides were detected only in oysters and Chemcatcher®. Overall, the use of three complementary sampling approaches demonstrated a high level of pesticide input into the Richmond River estuary, highlighting the usefulness of oysters as biomonitors for some pesticides.

Effect-based monitoring of two rivers under urban and agricultural influence reveals a range of biological activities in sediment and water extracts

Chemical contaminants, such as pesticides, pharmaceuticals and industrial compounds are ubiquitous in surface water and sediment in areas subject to human activity. While targeted chemical analysis is typically used for water and sediment quality monitoring, there is growing interest in applying effect-based methods with in vitro bioassays to capture the effects of all active contaminants in a sample. The current study evaluated the biological effects in surface water and sediment from two contrasting catchments in Aotearoa New Zealand, the highly urbanised Whau River catchment in Tāmaki Makaurau (Auckland) and the urban and mixed agricultural Koreti (New River) Estuary catchment. Two complementary passive sampling devices, Chemcatcher for polar chemicals and polyethylene (PED) for non-polar chemicals, were applied to capture a wide range of contaminants in water, while composite sediment samples were collected at each sampling site. Bioassays indicative of induction of xenobiotic metabolism, receptor-mediated effects, genotoxicity, cytotoxicity and apical effects were applied to the water and sediment extracts. Most sediment extracts induced moderate to strong estrogenic and aryl hydrocarbon (AhR) activity, along with moderate toxicity to bacteria. The water extracts showed similar patterns to the sediment extracts, but with lower activity. Generally, the polar Chemcatcher extracts showed greater estrogenic activity, photosynthesis inhibition and algal growth inhibition than the non-polar PED extracts, though the PED extracts showed greater AhR activity. The observed effects in the water extracts were compared to available ecological effect-based trigger values (EBT) to evaluate the potential risk. For the polar extracts, most sites in both catchments exceeded the EBT for estrogenicity, with many sites exceeding the EBTs for AhR activity and photosynthesis inhibition. Of the wide range of endpoints considered, estrogenic activity, AhR activity and herbicidal activity appear to be the primary risk drivers in both the Whau and Koreti Estuary catchments.

The 2021 Nigerian Twitter ban: A text-analytics and survey insight into public reactions and outcomes in the early weeks of the ban

The suspension of the micro-blogging platform, Twitter, by the federal government of Nigeria on 5 June 2021 for ‘consistent non-removal of inciting and divisive contents’, undoubtedly generated mixed feelings among social media users in and outside the country. Hinging on Ball-Rokeach &amp; DeFleur’s Media Systems Dependency theory, this study adopts a combination of text mining, sentiment analysis and survey approaches to make evident social media users’ reactions to the Twitter ban in 2021. Of the 3885 social posts that were sampled across three platforms (Facebook, Twitter and Nairaland) between 5 June and 16 July 2021, 73% decry while just 27% extol the Twitter ban action. The Nvivo word frequency results showed that the top five keywords used across the sampled posts were: ‘end’, ‘#twitterban’, ‘unlawful’, ‘suspension’ and ‘Nigeria’ ( n = 11,925; 24%), suggesting that majority of users were unhappy with the shutdown. The complementary opinion sampling conducted on students of Nile University of Nigeria revealed that the majority of the 319 sampled respondents (264; 83%) responded to VPNs to access and use Twitter despite the ban. Among the daily Twitter habits of the respondents most affected by the shutdown were Trending Topics Search (22%), Social Engagement (20%), Daily News Search (20%), Product Search (13%), Product Marketing (10%), Customer Relations (9%), Jobs Search (4%) and others (2%). The study recommends the consideration of better sanctioning means for erring social media companies that will not stifle the exchange of ideas online in this democratic age.

New records for the wild bee fauna (Hymenoptera, Anthophila) of Serbia

Numerous scientific projects have been initiated with the aim of tackling the decline in insect pollinators, a crucial group for the functioning of terrestrial ecosystems. One of the first steps is to address information gaps on species spatial distribution, diversity, and abundance that prevent effective conservation actions in Europe. Given that Serbia belongs to the understudied areas, efforts are being made to improve knowledge of its bee diversity and abundance. The present study includes the monitoring of bees at 54 sites, surveyed three times during 2022. The conducted protocol combined two methods, transect walks and pan traps, resulting in the discovery of 312 bee species. The main results present the records of 25 species, not previously mentioned in Serbia, while another important finding is the confirmation of the presence of 26 species, without any available records from the 21st century. Moreover, 79 here examined species were known only from literature-based data. Six of the recorded species are considered threatened and 67 (10 newly recorded) have been assessed as Data Deficient in the European Red List of Bees. Therefore, the present study not only contributes to an update and confirms the list of bee species in Serbia, that now counts 731 species, but also provides additional information about European distribution, required for new assessment at the European level. In addition, the results indicate that the combination of complementary sampling methods is an effective way to assess bee diversity and abundance.

A comparison of two widely used methods for estimating taxonomic and functional diversities of epigeal arthropods in some temperate grasslands

AbstractSuction sampling is increasingly being used to estimate abundance and diversity of epigeal arthropods, yet no study has quantified its efficiency to simultaneously assess diversity at different taxonomic and functional scales. Here, we evaluated the efficiency of this method (G‐Vac) relative to the pitfall (Barber) trap, which has been used for a long time, and their possible complementarity. To do that, we compared several diversity metrics of a wide range of arthropod taxa, with a particular focus on spiders (species level), and using functional traits such as trophic diet, hunting guild, and body size. Sampling took place in some coastal grasslands of Brittany (France) using a spatially paired design of vacuuming and unfenced pitfall trapping. In total, 21159 arthropods were identified to order or family levels, including 1018 adult spiders identified to species. Suction sampling was more efficient than pitfall trapping in collecting phytophagous arthropods, web‐builders, and small species living in the vegetation compared to detritivores, large‐bodied arthropods, and spiders living near the soil surface. We conclude that short‐term G‐Vac suction is more interesting than pitfall trapping to obtain a ‘snapshot’ of patterns in taxonomic richness. However, for assessing functional diversity, G‐Vac suction and pitfall trapping are complementary sampling methods.

Detecting functional rarity in a hyperdiverse Amazonian dung beetle assemblage

The functional space of an ecological community is not evenly filled by its species. Instead, it is usually divided into areas of high species density, where species with common combinations of functional traits are grouped into species rich clusters, while lower density areas are filled with species poor clusters or isolated species with uncommon or unique combinations of traits. Species whose functional traits differ from those of the rest of the community are expected to play distinct ecological roles and over-contribute to ecosystem functionality. Sampling methods used to characterize arthropod assemblages usually target subsets of the community and filter species based on their functional traits, reducing the probability of detecting species with uncommon combinations of functional traits. Consideration of these species is particularly important for characterizing the functional structure and resilience of ecological communities inhabiting threatened ecosystems such as lowland Amazonian rainforests, in which dung beetles play multiple ecological roles and are commonly used as ecological indicators. In this study, we characterize the functional structure of a diverse Amazonian dung beetle assemblage using five different sampling methods (dung- and carrion-baited pitfalls, dung-baited aerial traps, flight interception traps, and visual transects) and 18 different functional traits. Our main objective is to assess the suitability of these methods for the detection of the functional volume of the assemblage and of species with uncommon or unique combinations of functional traits that are expected to support vulnerable ecosystem functions. We found that, although dung-baited pitfalls (DPF) detected the highest species richness and proportion of the functional volume, they did not detect 30 species out of 103 and over 20% of the functional volume of the assemblage. The additional sampling methods captured more species with uncommon combinations of functional traits than expected by chance, some of which were trophic specialists not attracted to DPFs. The use of complementary sampling methods resulted in a better characterization of the functional structure of dung beetle communities inhabiting both terra firme and floodplain Amazonian rainforests and revealed functional resilience and rare species playing ecological roles overlooked by DPFs. The consideration of these species is of great importance given the threats that tropical rainforests face worldwide.