Beetle Assemblages Research Articles

Ecological indication metrics on dung beetles metacommunities in native forests and Pinus monocultures

Beetles of the subfamily Scarabaeinae are commonly used as ecological indicators in studies about the effects of environmental changes. We analyzed the influence of the type of habitat, vegetation, mammals (as food resource), and temperature on dung beetle metacommunities in subtropical native forests and Pinus monocultures to evaluate the factors driving these assemblages. In the summer of 2018/2019, we sampled 12 areas in Southern Brazil, six Pinus monocultures and six native forests. We performed a dispersal test, applying a marking-recapture method. Some recaptures occurred in different habitats, showing low dispersal between habitats. We recorded behavioral activities confirming the use of both native forest and Pinus areas. The metrics did not reflect the difference in the environmental quality of the areas regarding species richness and diversity in different habitats. This shows that these metrics are not the best when using dung beetle assemblages as ecological indicators of biodiversity loss resulting from land-use changes, requiring complementing the analysis with composition analysis methods. When we partitioned beta diversity between habitats, we observed a dissimilarity between Pinus monocultures and native forest assemblages due to species substitution, with many species contributing to the dissimilarity between habitats. In our structural equation models, the influence of environmental factors on metacommunities showed no predictor related to dung beetle richness, but several variables influenced their abundance.

Response of the dung beetle community to different climatic zones: Does the land use system matter?

AbstractThe conversion of Brazilian savanna into exotic pastures leads to the loss of dung beetles and a decrease in their contribution to ecological functions. We hypothesized that the dung beetle communities from exotic pastures would show greater significant differences between climatic zones, when contrasted to communities from Brazilian savanna in the same region, since dung beetle assemblages in pastures are more simplified. We assessed which variables (purpose of production, type of management, percentage the habitat per buffer, soil penetration resistance, pasture area and herd size) affect more the dung beetle community in exotic pastures. We carried out this study in 48 areas of native Brazilian savannas and exotic pastures distributed across four bioclimatic zones: BZ1, hot with three dry months; BZ2, hot with 4–5 dry months; BZ3, sub‐hot with 4–5 dry months and BZ4, meso‐thermal with 4–5 dry months of Minas Gerais State, Brazil. In each BZ, six areas of Brazilian savannas and six areas of exotic pasture were selected. In the Brazilian savanna areas, the species richness, abundance and biomass of dung beetles did not differ between the bioclimatic zones, unlike the exotic pastures. The composition of the dung beetle community was different between land use systems and between bioclimatic zones; the interaction between the two factors was also significant. Our results provide evidence that dung beetle communities active in exotic pastures are more susceptible to climatic environmental variations than communities from more complex and stable habitats, such as savannas. Finally, the best model suggested that all the six variables combined explained about 91% of the total variability in species composition observed between sampling sites.

Human Disturbance Affects Dung Beetle Assemblages in French Guiana Forests

French Guiana forests are threatened by increasing human activity such as infrastructure development, facilitating access to the forest and, therefore, logging, mining, farming and hunting. To highlight the impact of human pressure on the forest fauna, dung beetle assemblage was analyzed near Saint-Georges-de-l’Oyapock and compared with other sites in French Guiana, considering the distance to the main city and forest cover loss as proxies of human activities. Hill numbers and beta diversity were calculated. Non-metric multidimensional scaling and redundancy analyses were carried out to disentangle the effect of the distance to the nearest city and forest cover loss as proxies of human pressure, but also temperature and rainfall as proxies of climatic variations on dung beetle assemblage. Species richness increased significantly with the distance to the nearest city and decreasing forest cover loss. Assemblage structure varied among sites mainly with distance to the nearest city but also with rainfall. It varied also with forest cover loss, but not significantly. This study showed that human disturbances and climatic conditions, even if represented by proxies, affected dung beetle assemblage structures in French Guiana forests.

Effects of Dispersed and Aggregated Retention Forestry and Small-sized Clear-cuttings in Conifer Plantations on Carabid Beetle Assemblages

Effects of Dispersed and Aggregated Retention Forestry and Small-sized Clear-cuttings in Conifer Plantations on Carabid Beetle Assemblages

Effects of elevation and slope on the alpha and beta diversity of ground-dwelling beetles in Mt. Jirisan National Park, South Korea

• A total of 67 species and 12,304 individuals from Mt. Jirisan. • Higher species richness and abundance from the northern slope than the southern slope. • Species richness increased with elevation and the abundance showed hump-shaped. • Spatial turnover for the mountain and nestedness for slope level. • Ground beetle assemblages depended on elevation and soil. We examined the diversity of ground-dwelling (epigaeic) beetles at different elevations of the northern and southern slopes of Mt. Jirisan National Park, South Korea. We selected eight study sites from both slopes and collected the beetles 10 times from May 2018 to August 2019 using pitfall traps. We collected a total of 67 species and 12,304 individuals and found higher species richness and abundance among the beetles from the northern slope (54 species and 6,969 individuals) than the southern slope (46 species and 5,335 individuals). We observed that the proportion of species based on the biogeographic affinity (Palearctic or Oriental) did not depend on the elevation and slope. The species richness increased with elevation and the abundance showed hump-shaped with a peak at 800 m. While the overall beta diversity was similar at the mountain and slope levels, the underlying processes such as spatial turnover and nestedness differed at the mountain and slope levels, respectively. We found that the ground beetle assemblages depended on elevation and soil characteristics such as soil organic matter and pH but were unaffected by the vegetation type.

Rapid recovery of boreal rove beetle (Staphylinidae) assemblages 16 years after variable retention harvest

Post‐harvest recovery of biodiversity is one of important goals in modern forestry. A variable retention (VR) approach has been of particular interest in North America because it promotes rapid faunal recovery, while minimizing negative lasting impacts of logging on the natural fauna. We studied responses of rove beetles (Coleoptera: Staphylinidae) to a broad range of retention harvests (2, 10, 20, 50 and 75% retention) in comparison to uncut controls as part of the Ecosystem Management Emulating Natural Disturbance (EMEND) experiment in the boreal mixedwood forest of western Canada. We sampled beetles using pitfall traps 1, 2, 11 and 16 years post‐harvest in replicated (n = 3) stands representing four cover types (deciduous‐dominated, deciduous with spruce understory, mixed and coniferous‐dominated). We collected 74 263 individuals distributed across 99 species (excluding Aleocharinae). Estimated species richness was highest in clear‐cuts until year 11, but by year 16 species richness was similar among treatments. Species composition initially varied strongly in relation to intensity of harvest treatments, but overall variation decreased with time, and by year 16, species composition overlapped among most treatment combinations. Assemblages recovered more quickly in early successional (deciduous‐dominated) than in late successional (mixed and conifer‐dominated) stands. Overall, our results show that rove beetle assemblages in stands harvested to all VR prescriptions converged more rapidly toward those in fire‐origin mature stands than did assemblages in clear‐cuts over the first 16 years post‐harvest. Thus, it demonstrates that even modest levels of forest retention can facilitate the recovery of staphylinid assemblages in managed landscapes.

Impact of Water Retention Practices in Forests on the Biodiversity of Ground Beetles (Coleoptera: Carabidae)

This study was carried out in an area covered by the “Increasing retention capacity and prevention of floods and droughts in forest ecosystems in lowland areas” land drainage development project. The aim was to evaluate the impact of transformations in a habitat following the project’s implementation on the structure of assemblages of epigeic ground beetles, in the context of the overall trend of decreasing biodiversity. The entomological observations were commenced before launching the planned hydro-technical development at the study area and were repeated 11 years later. During the two years of observations (2008 and 2019), 3311 specimens of ground beetles, representing 89 species, were captured. Water regulation affected the composition of ground beetle assemblages. After the small water retention program had been completed, a quantitative and qualitative decrease in ground beetles was observed. The groundwork for the development caused some disturbances in the habitat, leading to, amongst other things, higher soil moisture, which was conducive to the establishment of ground beetle assemblages other than those observed before the water retention project. After the hydro-technical objects had been constructed, the share of large and small zoophages with higher moisture preferences (hygrophilous species) increased, while the contribution of xerophilous hemizoophages decreased.

Water beetles (Coleoptera: Haliplidae, Dytiscidae, Helophoridae, Hydrophilidae, Hydraenidae, Elmidae, Psephenidae, Scirtidae) of the Slavíč river basin, Czech Republic

Abstract Twenty-three sites within the Slavíč river basin (Silesia, Czech Republic) were surveyed to obtain up-to-date information on water beetles in the area. In total, 46 species comprising eight families were recorded. Significant findings included Ochthebius melanescens Dalla Torre, 1877, Hydrocyphon deflexicollis (Müller, 1821) (both endangered), Hydraena morio Kiesenwetter, 1849, Eubria palustris (Germar, 1818) (both vulnerable), Hydraena minutissima Stephens, 1829 (near threatened) and Elodes pseudominutus Klausnitzer, 1971 (data deficient). The Slavíč water beetle assemblage consisted mainly of typical rheophilic species, many characteristic for cold, mountainous waters, the most common beetles recorded being representatives of the families Elmidae and Hydraenidae. The species spectrum was significantly enriched by species found in non-riverine habitats along the Slavíč River floodplain (e.g. springs, wetlands and ponds), with representatives of the families Dytiscidae, Haliplidae and Hydrophilidae dominating.

Landscape Heterogeneity Determines the Diversity and Life History Traits of Ground Beetles (Coleoptera: Carabidae)

Functional diversity is crucial to ecosystem functioning in agricultural landscapes. Intensive agriculture has led to habitat homogeneity and thus a decrease in biodiversity and the disappearance of useful epigeic fauna. This study investigated how local habitat types in an agricultural landscape affect the assemblage parameters (abundance, species richness and Shannon–Wiener diversity index) and life history traits of ground beetles (Coleoptera: Carabidae). The study was conducted in four habitat types: Orchard, meadow, shrubs, and forest. In each type, 12 sampling transects were selected, in which individuals were caught in pitfall traps. Non-metric multidimensional scaling revealed significant differences in ground beetle (Coleoptera: Carabidae) assemblage composition between habitats. The generalized linear model showed that the habitat type influenced the beetles’ assemblage parameters and life history traits. Abundance, number of species, and species diversity were highest in the orchard. The occurrence of large brachypterous predators was also strongly dependent on habitat heterogeneity. Their presence in the orchard depended on their distance from semi-natural habitats (shrubs or forest). The results underscore the importance of habitat heterogeneity for populations of predatory Carabidae in intensively used agricultural landscapes and demonstrate the role of functional parameters, providing detailed information on agroecosystem condition and functioning.

Importance of grassy and forest non-crop habitat islands for overwintering of ground-dwelling arthropods in agricultural landscapes: A multi-taxa approach

Non-crop habitats are supposed to provide valuable resources to beneficial arthropods inhabiting agricultural landscapes during both the growing and winter seasons. Unfortunately, studies focused on the performance of non-crop habitats during the winter period are much less abundant, despite their importance for efficient biodiversity conservation measures. In this study, we assessed the distribution of ground-dwelling arthropods overwintering on arable land as well as the boundaries and interiors of neighbouring grassy and forest non-crop habitat islands. Myriapods, spiders, carabid and rove beetles were collected using a combination of quadrat sampling (soil sampling) and pitfall trapping. Our results revealed the importance of both non-crop habitat islands for overwintering arthropods, though slightly higher abundance and species richness were recorded in forest compared to grassy islands. Abundance and species richness of overwintering arthropods were lower on arable land for all the investigated taxa. Carabid and rove beetles overwintered more on non-crop boundaries than interiors, whereas spiders and myriapods used both boundaries and interiors. Landscape composition had stronger effects on carabids and myriapods collected with pitfall traps, which were benefitted in landscapes with high non-crop habitat cover. Grassy and forest non-crop habitat islands hosted different assemblages of myriapods, carabids and rove beetles, highlighting the complementarity of both non-crop habitat types for ground-dwelling arthropods. We recommend to preserve all existing non-crop habitat patches and to create new permanent non-crop habitat patches in intensively managed agricultural landscapes, as even relatively small non-crop habitat islands within the cultivated land can play a relevant role for overwintering arthropods.

High-resolution 3D forest structure explains ecomorphological trait variation in assemblages of saproxylic beetles.

Climate, topography and the 3D structure of forests are major drivers affecting local species communities. However, little is known about how the specific functional traits of saproxylic (wood-living) beetles, involved in the recycling of wood, might be affected by those environmental characteristics.Here, we combine ecological and morphological traits available for saproxylic beetles and airborne laser scanning (ALS) data in Bayesian trait-based joint species distribution models to study how traits drive the distributions of more than 230 species in temperate forests of Europe.We found that elevation (as a proxy for temperature and precipitation) and the proportion of conifers played important roles in species occurrences while variables related to habitat heterogeneity and forest complexity were less relevant. Furthermore, we showed that local communities were shaped by environmental variation primarily through their ecological traits whereas morphological traits were involved only marginally. As predicted, ecological traits influenced species' responses to forest structure, and to other environmental variation, with canopy niche, wood decay niche and host preference as the most important ecological traits. Conversely, no links between morphological traits and environmental characteristics were observed. Both models, however, revealed strong phylogenetic signal in species' response to environmental characteristics.These findings imply that alterations of climate and tree species composition have the potential to alter saproxylic beetle communities in temperate forests. Additionally, ecological traits help explain species' responses to environmental characteristics and thus should prove useful in predicting their responses to future change. It remains challenging, however, to link simple morphological traits to species' complex ecological niches. Read the free Plain Language Summary for this article on the Journal blog.

Hierarchical trait filtering at different spatial scales determines beetle assemblages in deadwood

Abstract Environmental filters—including those resulting from biotic interactions—play a crucial role during the assembly of ecological communities. The importance of scale has thereby been acknowledged but filters at different scales have rarely been quantified in relation to each other, although these hierarchically nested filters eventually determine which communities assemble from a regional species pool. Saproxylic beetles offer an ideal system to study such hierarchically nested environmental filters. Three steps of filtering during the community assembly of these deadwood‐dependent beetles are proposed. First, starting from a regional species pool, species must disperse to forest sites. Second, within a site, individuals need to find a patch with preferred microclimatic conditions. Third, the conditions of a single deadwood object (i.e. tree species identity, decomposition stage) at this patch will determine, which species colonise and establish. To study these hierarchical filters, we used unique long‐term data ets of saproxylic beetle diversity from trap catches at 29 sites and from emergence traps on 694 experimentally installed deadwood logs at the same sites in three regions in Germany. To relate different environmental filters to beetle assemblages, we used a set of 13 functional traits that are hypothesised to relate to different filters at different scales. We show that all three hierarchical filtering steps resulted in reductions of functional diversity and simultaneous shifts in the functional composition of beetle assemblages, reflecting the roles of different traits in response to different filters. Trait composition changed most strongly at the last filtering step, that is, depended on tree species identity and decomposition stage. We showed that if community assembly is analysed as a hierarchical multi‐step process based on data from different spatial scales, environmental filters can be quantified at these scales. As such, a better understanding of the role that different filters play at different spatial scales can be reached. Read the free Plain Language Summary for this article on the Journal blog.

Ground beetle assemblages respond to motorway proximity through changes in functional rather than taxonomic diversity in a grassland ecosystem

Despite being among the best-studied insect groups in road ecology, assemblage-level effects of major roads on ground beetles have rarely been investigated from the functional perspective. In this study we adopted both species-based and trait-based approaches to investigate spatial dynamics of ground beetle assemblages with respect to motorway proximity and identify main environmental drivers of the observed changes. In 2018, ground beetles were sampled by pitfall traps within homogeneous portions of a grassland habitat in Lika region, Croatia, in eight locations at five distances from a motorway: 10, 25, 50, 100 and 500 m. While no significant spatial patterns were found in taxonomic assemblage metrics, confirming that road-related effects are less prominent in open compared to closed habitat types, functional diversity of ground beetles increased with motorway proximity, possibly owing to an edge effect. Our findings show that, in grassland ecosystems, motorways are likely to affect ground beetle assemblages primarily through changes in vegetation height, with highly vegetated roadsides potentially acting as habitat corridors or supplementary habitats for generalist and mesophilous species.

Functional diversity and redundancy of amphibians, ants, and dung beetles in passive and active cloud forest restoration

Forest restoration practices have increased globally, with positive consequences for biodiversity conservation. However, our understanding of the variation in ecosystem functioning recovery presented among different restoration strategies remains limited, and few studies have compared the functional diversity of contrasting faunal assemblages. Here, we assessed how the functional diversities and functional redundancies of amphibian, ant, and dung beetle assemblages vary among forests of the same age (23 years) under active (native mixed plantations) and passive (natural regeneration) restoration, cattle pasture (degraded ecosystem), and mature cloud forest (reference ecosystem). We also explored how environmental variables relate to the functional diversity of each animal assemblage. We found that functional diversity (measured as functional richness, functional evenness, and functional divergence) and functional redundancy in the three faunal assemblages were similar between the two restoration strategies. However, some attributes of functional diversity did not reach the values of the reference ecosystem, especially in the amphibians and dung beetles. Environmental variables related to functional diversity also depended on the taxonomic group and the metric of functional diversity, but the most important of these variables were vegetation condition, canopy cover and tree density. In our study system, passive and active restoration produced similar recovery rates of functional diversity of the faunal assemblages. Regardless of the restoration strategy implemented, long-term adaptive management strategies must be implemented to ensure full recovery of biodiversity and functionality in Neotropical cloud forest landscapes.

Forest management affects saproxylic beetles through tree species composition and canopy cover

Forest management has been shown to affect biodiversity, but the effects vary among taxa and studies. Due to their host-tree preferences, many saproxylic, i.e. deadwood-dependent, beetle species are likely affected by forest management via changes in tree species composition. However, further structural differences caused by forest management, such as microclimatic conditions, may interfere with effects of tree species. We lack a more detailed understanding of how forest management intensity influences saproxylic beetles through tree species composition and structural properties.We analyzed the effect of forest management on saproxylic beetles using an eight-year dataset collected from 379 experimental logs of 13 different tree species, which were exposed in forests of different management intensity in three regions of Germany. To quantify forest management intensity, we first used a composite index (ForMI) which considers the share of locally non-native tree species, the origin of deadwood and the harvesting rate and then replaced it by five forest structural and compositional properties. This two-step approach allowed to assess the overall effects of management summarizing different aspects and to identify the main forest attributes driving these overall effects. We further investigated whether the effects differ between beetle assemblages emerging from conifer and broadleaf logs (host level), and between generalists, conifer-specialists, and broadleaf-specialists (beetle specialization level).Abundance and species richness increased with increasing ForMI for all beetles, generalists, and conifer-specialists, but not for broadleaf-specialists.Effects of ForMI were stronger for assemblages emerging from conifer than broadleaf logs. Among the evaluated structural and compositional variables, strongest effects were observed for conifer share at stand level and canopy cover. Conifer share positively affected the species richness of all beetles, generalists and conifer specialists, but not of broadleaf specialists. Canopy cover negatively affected all beetles, generalists and conifer specialists, but did not affect broadleaf specialists.Our results show that major drivers behind effects of forest management on saproxylic beetles are differences in tree species composition and canopy cover. Effects differ between beetle groups depending on their host specialization. Forest management decisions regarding tree species composition should therefore more strongly consider their effects on saproxylic beetle diversity to meet conservation goals also in the future.

Structure and Composition of Dung Beetle Assemblages (Coleoptera: Scarabaeidae) in a Livestock Ranch in Central Uruguay: Responses of Functional Groups and Species to Local Habitats and Trophic Resources

Dung beetles play an important role in the sustainability of agroecosystems by providing various ecosystem services. The spatial distribution of species can be affected by vegetation structure and soil type at a small scale. Our study was conducted in a cattle ranch in which there were two grassland areas with different types of soil (humid silty clay vs. dry clay) and a plantation of Eucalyptus L'Hér. (Myrtaceae). The aim of this study was to analyze variations in diversity and structure of dung beetle assemblages by considering the feeding guilds (coprophagous, necrophagous, and generalists) and functional groups (paracoprids, telecoprids, and non-nester dwellers) among the three mentioned habitats. Nine pitfall traps baited with cow dung, horse dung, or carrion were placed simultaneously at each site every two weeks over the course of a year. Coprophagous species dominated over necrophagous and generalist species in abundance and biomass in each habitat. The highest species richness occurred in the pasture on humid silty clay soil and the lowest in the Eucalyptus plantation. Abundance and biomass of paracoprids were highest in the pasture on humid silty clay soil, while non-nester dwellers dominated in the pasture on dry clay soil and the Eucalyptus plantation. Large paracoprids were almost non-existent in the pasture with dry clay soil. In the Eucalyptus plantation, the marked reduction in species richness, particularly of telecoprids and paracoprids, the increase in species dominance, and the absence of rare species were clear indicators of an adversely affected environment.

Neighboring plants and core herbivores determine the importance of Swietenia macrophylla in the plant–herbivore network

Species contribute differently to the structure and stability of networks of interacting species. However, species contributions to the importance of other species is usually neglected, thus limiting our understanding of species dynamics beyond the general network structure. We combined knowledge on diversity effects on focal species and network ecology to analyze the influence of plants and herbivores on big-leaf mahogany's (Swietenia macrophylla) importance in the plant–herbivore network. To this end, we built interaction networks using information from a large-scale tree diversity experiment and performed computer simulations of species removal with redistribution of interactions. We compared the importance of big-leaf mahogany in the observed networks to simulated networks where we removed: (a) tree species with similar beetle assemblages to mahogany, (b) the most interconnected (core) tree species and (c) the core beetle species. Removal of the core and similar tree species increased the importance of mahogany, whereas eliminating core beetle species decreased it. Interestingly, the effect of core tree species on mahogany’s importance was mediated by core beetles (R2 = 0.46). Neither tree nor core beetle species’ effects were contingent on tree species richness or abundance. These results indicate that highly connected tree and herbivore species jointly determine the role of mahogany in the plant–herbivore network. Likewise, these results provide insight into the effect of tree species composition and highly interactive herbivores in shaping the role of species in the herbivore network.

Micro‐habitat drivers of saproxylic beetle assemblages in old woodlands of Mediterranean cork oak (Quercus suber)

Abstract Cork oak landscapes are fascinating ecosystems, historically managed for cork extraction. The persistence in this habitat of many hollow veteran trees provides suitable micro‐habitats for saproxylic beetles. We investigated the saproxylic beetle community of two isolated cork oak woodlands of central Italy with different degree of recovery after human transformation: (1) an open woodland and (2) a dense mixed woodland, both dominated by cork oak trees. We found endemic, rare and threatened saproxylic beetles in both the areas, confirming the important conservation value of cork oak landscapes. In the open woodland we observed a higher number of species in all trophic categories, except for mycophagous specialists. Several microhabitat variables reflected the different stage of recovery of the two woodlands. Our findings suggest the crucial role of diversified environments in protected areas: even a small difference in the degree of recovery (i.e., tree closeness) can affect the number of beetle species. Specifically, we found (1) more xerophilous species in the open woodland and (2) more mesophilous species in the dense mixed woodland.

Body size and the urban heat island effect modulate the temperature–size relationship in ground beetles

AbstractAimBody size is a key trait linked to other life history traits and influences several individual‐, community‐ and ecosystem‐level characteristics, processes, functions and services. Ecological and evolutionary body size responses at the intra‐ and inter‐specific level to thermal geographic gradients (e.g. latitudinal or altitudinal ones) are widely studied. Whether this temperature‐size relationship remains true for community‐wide body size is still largely unknown.LocationNorthern temperate region.TaxonGround beetles (Carabidae).MethodsWe assessed the temperature‐size relationships using data from 11 northern temperate locations, spanning 25 latitudinal degrees. Furthermore, we quantified the effects of potential competing factors, such as body size and habitat preference of carabid assemblages and sub‐assemblages along urbanisation gradients, as well as the urban heat island (UHI) effect on this relationship.ResultsWe found significant negative relationship between the community‐wide mean body size and the geographical latitude (converse Bergmann cline) for the whole ground beetle assemblage and the sub‐assemblages of large‐bodied species. This relationship was stronger in the urban localities than in rural ones. For the sub‐assemblages of small‐sized species, the relationship was not significant. We found significant negative relationship between the community‐wide mean body size and the latitude for the sub‐assemblages of both the non‐forest and the forest species, and these became stronger in the urban habitats.Main ConclusionsOur results highlight the leading role of the individual body size and the UHI effect in determining the community‐wide body size–latitude relationship in ground beetles.

Comparative effect of forest cutting and mammal hunting on dung beetle assemblages in Chocó Biogeographic forests in Colombia

Comparative effect of forest cutting and mammal hunting on dung beetle assemblages in Chocó Biogeographic forests in Colombia