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Soil unsealing, the process of removing the impermeable top layer of soil, is increasingly advocated by urban planning policies. The role of unsealed areas in biodiversity conservation, particularly soil biodiversity, remains strongly understudied and especially in understanding the recolonization dynamics of soil biodiversity in these new habitats. Besides, the various types of soil cover resulting from soil unsealing could potentially influence the recolonization kinetics. This study focused on 79 unsealed plots located in 14 schoolyards along the French Mediterranean coast, investigating ant communities through the placement of 485 baits on unsealed plots. Two variables were considered: the duration since soil unsealing (1 or 2 years) and the type of soil cover (wood chips, plantations mulched with wood chips or lawns). Remarkably, these unsealed areas act as habitats for ants from their very first years of creation: a rich number of ant species (21 species; a fifth of the regional pool and 10% of the metropolitan French species) has been observed. Additionally, notable changes in ant communities were evident within a single year: plots unsealed for 2 years exhibited significantly higher indices of ant abundance and species richness compared to those unsealed for 1 year. However, the construction of these spaces influences the present communities, with wood chip-covered areas significantly less rich and abundant in ants compared to other ground cover types. These findings represent a promising starting point and offer insights into the potential of such projects for soil biodiversity conservation.

AIM: Mountain regions are particularly well‐suited for investigating the impact of climate change on species ranges because they encompass both upper and lower limits of species distribution. Here, we investigate changes in the elevational distribution of dung beetle species (Coleoptera: Scarabaeoidea) in two separate mountain regions in Europe. LOCATION: South‐western Alps (France) and Sierra Nevada (Spain). METHODS: We compared historical and current data on dung beetle distributions along elevation gradients for 30 species in the SW Alps and 19 species in the Sierra Nevada. We tested for significant changes between survey periods in three parameters: mean elevation and upper and lower range limits. RESULTS: We found up‐slope range shifts for 63% and 90% of the species in the SW Alps and Sierra Nevada, respectively. Up‐slope range shifts resulted mainly from expansion of upper range limits in the SW Alps and from changes of both range limits in the Sierra Nevada. The magnitudes of range shifts were consistent with the level of warming experienced in each region, but they also reflected the asymmetrical warming observed along the elevation gradients. Smaller changes were observed for species reaching their historical range limits at the higher elevations, associated with a non‐significant increase in temperature between periods. MAIN CONCLUSIONS: The differences observed between regions are related to the geographical position of each mountain range, which determines the characteristics (including thermal tolerance) of the regional species pool, and the level of warming, which determines whether maximum thermal tolerance has been exceeded for the majority of species in the region. Our results highlight the importance of considering both the biogeography of the mountain and the species pool under study when assessing the sensitivity of species to future climate change in mountain regions.

Aim In several ecosystems, the diversity of functional species traits has been shown to have a stronger effect on ecosystem functioning than taxonomic diversity alone. However, few studies have explored this idea at a large geographical scale. In a multisite experiment, we unravelled the relationship between ecosystem function and functional completeness of species assemblages using dung beetles as a model group, focusing on dung removal and secondary seed dispersal. Location Seventeen grassland locations across the Western Palaearctic. Methods We used a randomized block design with different exclosure types to control the dung and seed removing activities of individual functional groups of the local dung beetle assemblage. We classified dung beetle species according to resource specialization and into functional groups based on dung processing behaviour (dwellers, tunnellers, rollers) and body size (small, large). Additionally, we assessed the role of other soil macro‐invertebrates. By sampling the dung beetle community and measuring the remaining dung and seeds after the experiment, the impact of each functional group was estimated. Results Dung beetle assemblages differed along a north–south and east–west gradient. Dwellers dominated northernmost sites, whereas at lower latitudes we observed more tunnellers and rollers indicating a functional shift. Resource specialists were more abundant in southern and eastern areas. Overall, functional group diversity enhanced dung removal. More dung (+46.9%) and seeds (+32.1%) were removed in the southern sites and tunnellers and rollers were more effective. At the northernmost sites, where tunnellers were scarce or absent, other soil macro‐invertebrates removed the majority of dung. Main conclusions The conservation of functionally complete dung beetle assemblages is crucial to maintain the ecosystem functions provided by dung beetles. Given the latitudinal variation in functional group diversity, it is reasonable to expect compositional changes due to climate change. These changes could lead to increased dung removal and a higher secondary seed dispersal rate in northern regions.

The current biodiversity crisis calls for rapid and wide-ranging surveys to assess living organisms. However, some taxa are more elusive than others, making monitoring challenging. This is the case for soil invertebrates, but new molecular technologies such as eDNA metabarcoding could help to alleviate this problem. In this study, we evaluated the feasibility of using an eDNA approach to survey dung beetles, adapting existing monitoring methods for surveying dung fauna to enable eDNA collection in a non-destructive way. The main design idea is to capture species secretions and excretions from a serum-soaked nonwoven compress in a baited non-destructive trap. While the attractiveness of the device to dung beetles and the sampling protocol would benefit from further development, eDNA allowed the identification of more than 68% of trapped species and an identification of relative abundance match rate of 79%. The results of the study demonstrate the effectiveness of eDNA-based detection tools for the monitoring of dung beetles compared to standard surveying and identification techniques. Moreover, the adapted collecting device developed for the study could be used for similar surveys of other terrestrial invertebrates or even re-adapted. Ultimately, we hope this study encourages more non-invasive studies of insects by enabling others to utilize these emerging, non-destructive molecular techniques and therefore foster wide insect monitorings and conservation programs.Implications for insect conservationStandardization and optimization of sampling protocols for inventorying and monitoring is key to unlock invertebrates’ studies and conservation evaluations. Here we show how molecular tools, such as eDNA, are a promising way to gather rapidly ecological information without killing targeted populations by adapting traditional inventory tools. Newly developed NDC traps for dung beetles, inspired by CSR traps, allowed qualitative and quantitative information gathering in temperate agropastoral ecosystems opening the way to large scale eDNA monitoring to inform management and conservation schemes.

AIM: To determine the performance of different pseudo‐absence selection strategies on the prediction of species‐distribution models after 30 years of regional climatic and land use changes. LOCATION: Continental France and the Iberian Peninsula. METHODS: In this study, we used a large database of Coprophagous Scarabaeidae beetle records collected between 1970 and 1980 in continental France and the Iberian Peninsula to assess the relative performance of different modelling methods in predicting species distributions using current climate and land use information. We used maxent with standard settings and boosted regression trees with three different approaches to generate pseudo‐absences. We used historical data to model species distribution and then projected the models into the present. Each method's performance was then assessed by specific field sampling conducted at 20 different sites. RESULTS: Field validation demonstrated that model predictions were more accurate when pseudo‐absence data were selected from a sampling bias grid and that model evaluations based on test datasets can lead to false conclusions if not correctly calibrated. The study also demonstrated that the method in which pseudo‐absences are dealt with has a major impact on ecological conclusions. MAIN CONCLUSION: Correcting for spatial bias in collections datasets is of great importance for predicting future trends in species distributions. Uncorrected models showed a strong bias in their predicted species richness patterns.

Aim: To predict French Scarabaeidae dung beetle species richness distribution, and to determine the possible underlying causal factors. Location: The entire French territory has been studied by dividing it into 301 grid cells of 0.72 x 0.36 degrees. Method: Species richness distribution was predicted using generalized linear models to relate the number of species with spatial, topographic and climate variables in grid squares previously identified as well sampled (n = 66). The predictive function includes the curvilinear relationship between variables, interaction terms and the significant third-degree polynomial terms of latitude and longitude. The final model was validated by a jack-knife procedure. The underlying causal factors were investigated by partial regression analysis, decomposing the variation in species richness among spatial, topographic and climate type variables. Results: The final model accounts for 86.2% of total deviance, with a mean jack-knife predictive error of 17.7%. The species richness map obtained highlights the Mediterranean as the region richest in species, and the less well-explored south-western region as also being species-rich. The largest fraction of variability (38%) in the number of species is accounted for by the combined effect of the three groups of explanatory variables. The spatially structured climate component explains 21% of variation, while the pure climate and pure spatial components explain 14% and 11%, respectively. The effect of topography was negligible. Conclusions: Delimiting the adequately inventoried areas and elaborating forecasting models using simple environmental variables can rapidly produce an estimate of the species richness distribution. Scarabaeidae species richness distribution seems to be mainly influenced by temperature. Minimum mean temperature is the most influential variable on a local scale, while maximum and mean temperature are the most important spatially structured variables. We suggest that species richness variation is mainly conditioned by the failure of many species to go beyond determined temperature range limits.

By manipulating faeces during feeding and breeding, dung beetles (Coleoptera: Scarabaeidae) fulfil important ecosystem functions in terrestrial ecosystems throughout the world. In a pan-European multi-site experiment (MSE), we estimated the ecosystem functions of dung removal and secondary seed dispersal by differing combinations of dung beetle functional groups. Therefore, we classified dung beetles into five functional groups according to their body size and dung manipulation method: dwellers, large and small tunnelers, and large and small rollers. Furthermore, we set up a dung beetle sampling database containing all sampled dung beetles during the project. By identifying dung beetle specimens to the species level, we obtained a detailed insight into the dung beetle communities at each study location.By establishing experimental plots allowing and inhibiting specific combinations of functional groups in the local dung beetle assemblage from removing dung and seeds, we estimated the role of each group in dung removal and secondary seed dispersal during a 4-week period. We performed all experiments in grazed (semi-)natural grasslands, and used different dung types (cattle, horse, sheep, goat or red deer) to match the herbivore species grazing in close vicinity of each of the study areas. Simultaneously, we sampled dung beetle assemblages by using pitfalls baited with the same dung types as used in the experiments.This data paper documents two datasets collected in the framework of this MSE project. All the experiments took place between 2013 and 2016 at 17 study sites in 10 countries and 11 biogeographic zones. The entire dung beetle sampling dataset was published as a sampling event dataset at GBIF. The dataset includes the sampling results of all 17 study sites, which contain 1,050 sampling events and 4,362 occurrence records of 94 species. The second dataset contains the results of the dung removal and secondary seed dispersal experiments in which we used 11 experimental treatments and the five dung types mentioned above. This experimental results dataset holds all experimental results of the MSE project (11,537 records), and was published in the online data repository Zenodo.

The species richness distribution of the French Aphodiidae was predicted using Generalized Linear Models to relate the number of species to spatial, topographic and climate variables. The entire French territory was studied, divided into 301 0.72 × 0.36 degree grid squares; the model was developed using 66 grid squares previously identified as well sampled. After eliminating nine outliers, the final model accounted for 74.8% of total deviance with a mean Jackknife predictive error of 10.5%. Three richest areas could be distinguised: the western head (Brittany), southwestern France, and, to a lesser extent, the northeastern region. Sampling effort should now be focused on the western head, where no square was correctly sampled, and on southwestern France, which was recognised as a diversity hotspot, both for Aphodiidae and for Scarabaeidae. The largest fraction of variability (37%) in the number of species was accounted for by the combined effect of the three groups of explanatory variables. After controlling for the effect of significant climate and topographic variables, spatial variables still explain 27% of variation in species richness, suggesting the existence of a spatial pattern in the distribution of species richness (greater diversity in western France) that can not be explained by the environmental variables considered here. We hypothesize that this longitudinal spatial pattern is due to the relevance of a western colonization pathway along the glacial-interglacial cycles, as well as by the barrier effect played by the Alps.

ContextMediterranean landscapes from Europe have undergone recent biodiversity changes. The intensification of human activities and the fragmentation of open habitats now affect many taxonomic groups, such as dung beetles, which have benefited from centuries of extensive herding. Nevertheless, dung beetles’ responses to landscape composition have been rarely investigated in this context.ObjectivesWe explored how dung beetle communities (species occurrences, abundances and traits) were influenced by temperature and by soil and landscape characteristics and examined residual co-occurrence patterns that may reflect interspecific interactions.MethodsWe used an extensive dataset on Scarabaeinae dung beetles from southern France (31 species, 117 sites) to evaluate how landscape composition and fragmentation, climate and soil characteristics jointly influence dung beetle communities across this region. We used hierarchical joint species distribution models to characterize (co)variation in the responses of species and to connect such responses to species-specific traits.ResultsTemperature, soil and landscape characteristics shape dung beetle communities and species’ thermal tolerance was connected to their soil preferences. Fragmentation was negatively associated with beetle abundance while forest cover was positively associated with species richness and with abundance. There was little evidence of residual associations among dung beetle species, suggesting that species interactions do not play a major role in community assembly.ConclusionK-selected species were over-represented among the rarest species. The effects of fragmentation and forest cover indicate that a conservation plan based on connected, heterogeneous habitats with low-density grazing should be promoted to preserve ecological functions linked to these insects.

In southern Europe, an intensive agricultural abandonment occurs for more than a century. This change in land use concerns both farming and breeding and induces a large-scale expansion of forest habitats. In the Mediterranean region, which is a centre of endemism and species richness for many groups, a large amount of biodiversity is related to ancient agricultural practices. This current abandonment could consequently induce a drastic flora and fauna impoverishment. This study attempts to identify the consequences of the widespread Mediterranean forest expansion on dung beetle assemblages. Dung beetle assemblages were monitored monthly with dung-baited pitfall trapping in four Mediterranean sites from 250 to 2030 m in elevation. At each site, different grazed habitats (grassland, forest and shrubland or wooded grassland) were sampled during the most seasonally active period. In total, 61,645 specimens consisting of 70 species, namely 65 Scarabaeidae (42 Aphodiinae, 23 Scarabaeinae) and 5 Geotrupidae. Sixty-four out of the 70 sampled species (91.43%) were widely distributed in the Palaearctic region. A drastic loss in species richness consecutive to the replacement of grassland by forest was observed all along the elevation gradient: 63 species recorded in grassland habitat versus 60 and 45 species in shrubland and forest, respectively. There was often a loss in species richness according to elevation: 45 versus 30 species in low and high elevation, respectively. For Aphodiinae, the extension of forest also induced a shift in distribution across elevation. This important biodiversity loss that is mainly concerned with lowland thermophilous species was accompanied by crucial changes in the structure of assemblages. The measurement of alpha and beta-diversity in different habitats as well as between habitats across an elevation gradient is essential to our understanding of which habitats are required to best conserve biodiversity. Alpha diversity decreased from grassland to shrubland to forest. Intra-habitat alpha and beta-diversity decreased with elevation. Whereas, inter-habitat beta-diversity (spatial turnover) increased from grassland to shrubland and then to forest regardless of elevation. The contrarily, intra-site beta-diversity increased with elevation. Thus, at the regional scale, the spatial turnover decreased with elevation and increased with the vegetation cover. So, the composition and structure of dung beetle assemblages were affected by vegetation cover, which causes a decreasing abundance and species richness and could result in a drastic loss of dung beetles biodiversity in southern Europe.