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Wetlands are diverse and productive ecosystems endangered by human pressure, which degradation implies a biodiversity loss worldwide. Among the biological assemblages of these habitats, aquatic Coleoptera is one of the most diverse and useful groups when assessing the ecological conditions of the ecosystems they inhabit. The aims of the present study were to analyze the diversity and composition of aquatic Coleoptera assemblages in 24 wetlands protected by the Natura 2000 network of North-western Spain and the influence of environmental variables on the distribution of species, in order to detect differences between the different types of standing water habitats. A total of 11,136 individuals of 105 species belonging to 12 families of aquatic Coleoptera (Gyrinidae, Haliplidae, Noteridae, Paelobiidae, Dytiscidae, Helophoridae, Hydrochidae, Hydrophilidae, Hydraenidae, Scirtidae, Elmidae and Dryopidae) were collected. In general, wetlands presented high richness and diversity values, Dytiscidae and Hydrophilidae having the highest species richness. Most of recorded species have a wide biogeographical distribution and only 12 endemic ones were captured. Cluster and Non-Metric Multi-Dimensional Scaling (NMDS) analyses showed the clustering of the studied ponds and lagoons in four groups based on biological data. In general, the wetlands of each group seem to have distinct aquatic Coleoptera faunas, as showed by the most representative species. A combination of altitude, SST and hydroperiod was the best explaining factor of the distribution of the species throughout the study area. This study shows the high biodiversity of standing water habitats in North-western Spain and the usefulness of water beetles in establishing habitat typologies.

Biodiversity offsets are seen as a policy mechanism to balance development and conservation goals. Many offset schemes employ habitat restoration in one area to recreate biodiversity value that is destroyed elsewhere, assuming that recovery is timely and predictable. Recent research has challenged these assumptions on the grounds that restoration implies long time delays and a low certainty of success. To investigate these assertions, and to assess the strength of empirical support for offset policy, we used a meta-analytic approach to analyze data from 108 comparative studies of secondary growth (SG) and old-growth (OG) habitat (a total of 1228 SG sites and 716 OG reference sites). We extracted species checklists and calculated standardized response ratios for species richness, Fisher's alpha, Sorenson similarity, and Morisita-Horn similarity. We modeled diversity change with habitat age using generalized linear models and multi-model averaging, correcting for a number of potential explanatory variables. We tested whether (1) diversity of passively and actively restored habitat converges to OG values over time, (2) active restoration significantly accelerates this process, and (3) current offset policies are appropriate to the predicted uncertainties and time lags associated with restoration. The results indicate that in the best case, species richness converges to OG reference values within a century, species similarity (Sorenson) takes about twice as long, and assemblage composition (Morisita-Horn) up to an order of magnitude longer (hundreds to thousands of years). Active restoration significantly accelerates the process for all indices, but the inherently large time lags, uncertainty, and risk of restoration failure require offset ratios that far exceed what is currently applied in practice. Restoration offset policy therefore leads to a net loss of biodiversity, and represents an inappropriate use of the otherwise valuable tool of ecosystem restoration.

Urbanization is one of the most serious threats to stream ecosystems worldwide. It is crucial to understand its effects on stream organisms as a prerequisite for the mitigation of urban degradation. Our aim was to investigate the general effects of urbanization in a moderately urbanized landscape and to assess the relationship between local environmental variables and biotic attributes of macroinvertebrate assemblages. Multiple sites at low-order streams flowing from natural forested areas to moderately urbanized landscapes were surveyed. We found that local habitat properties presented degraded conditions at urban sites. Urbanization had a negative effect on the richness and Shannon diversity of macroinvertebrate assemblages, and altered assemblage composition. Biotic assemblage parameters showed negative, neutral or positive relationships with local physical parameters. Concrete cover was one of the most important variables, which explained a decreasing richness and diversity of macroinvertebrates. In natural conditions, microhabitat-level environmental variables significantly impacted community variation, while in degraded conditions microhabitat and site-level environmental variables had a substantial impact together. Individual streams showed considerable variability under natural conditions, as well as in their response to urban effects. Subsequently, the mitigation of the effects of urbanization might also need considerable variability in the type of actions required.

Groundwater-fed helocrene springs constitute hydrologically heterogeneous environment, vulnerable to human and climate-induced changes. Using quantitative samples of clitellate assemblages, we investigated whether hydrologically stable nearby streams can serve as refugia for species inhabiting helocrenes, prone to seasonal desiccation. As water conductivity constitutes the main environmental gradient of helocrene springs, we categorized them as low or high-conductivity sites and compared their assemblage diversity. We hypothesized that the spring–stream association can change along this gradient, expecting assemblage homogenization is promoted by high tufa precipitation, creating differences with tufa-free nearby streams. Contrary to this prediction, the assemblages of low-conductivity helocrenes were more homogeneous, being also significantly different from those in the streams. This result is related to the apparently more favorable tufa-free substrate at low-conductivity fens, as shown by the high taxa richness and the number of indicator species. Contrary to the other invertebrates, the clitellates differed between spring fens and streams only under acidic conditions. It seems that small adjacent streams can only serve as potential refugia for spring fen biota at sites with high conductivity, while at sites with low conductivity, clitellate assemblages differ more from those in adjacent streams and thus are more susceptible to disturbance.

Coastal lagoons are naturally stressed systems and experience changes in environmental conditions because freshwater inputs change environmental variables, mainly the salinity. We hypothesized that fish assemblages would change in structure and richness in three tropical lagoons that had different salinity ranges (a hyperhaline lagoon, 36–54; a euhaline lagoon, 16–40; and a mesohaline lagoon, 8–34). The assemblage structure differed among the three lagoons, and changed seasonally only in the mesohaline lagoon with the biomass being comparatively higher in summer than that in winter. The four environmental variables (salinity, temperature, turbidity and depth) explained a significant proportion of the variance, with salinity having the most significant effect (≈ 10% of the explained variation) on fish assemblage structure. The mesohaline lagoon, with the widest salinity range (from estuarine to marine conditions) and more loads of nutrient brought by small rivers’ inflows, was the most abundant (in fish number and biomass) system. The euhaline lagoon, with a salinity range closest to marine conditions, had the highest species richness as opposed to the hyperhaline lagoon that appeared to limit species abundance and richness, probably due to the stress of high salinity.

Caves are characterized by unique abiotic conditions such as limited light, and they therefore support distinct faunal assemblages that often include endemic species. Due to light limitations, photoautotrophic organisms are absent from many subterranean food-webs, which therefore predominantly rely on allochthonous nutrient sources. For this reason, hypogean habitats are expected to display lower assemblage diversity than that seen in epigean ecosystems. Bat guano, a major source of allochthonous nutrients in caves, varies substantially in composition based on its origin—whether it is produced by frugivorous or by insectivorous bats—and on its deposition site within the cave. This study examines how allochthonous nutrient sources and zones within caves influence arthropod diversity and assemblage composition. We found that both the type of allochthonous nutrient source and cave characteristics strongly affect the composition of arthropod assemblages. Our results show that caves harboring frugivorous bat colonies have a lower abundance of flies than caves with either insectivorous bat colonies or no bat colonies. Moreover, caves without bat colonies were seen to have low species richness of both detritivores and predators compared to caves housing either frugivorous or insectivorous bats. Additionally, species diversity and assemblage composition differed substantially between the twilight and dark zones of the caves. These findings demonstrate that allochthonous nutrient sources, the ecological zone, and the microhabitat within the cave are key drivers of arthropod assemblage composition and diversity. This study advances our understanding of cave ecology and underscores the importance of conserving diverse cave types for protecting their unique arthropod diversity.

Polyporous fungi, a morphologically delineated group of Agaricomycetes ( Basidiomycota ), are considered well studied in Europe and used as model group in ecological studies and for conservation. Such broad interest, including widespread sampling and DNA based taxonomic revisions, is rapidly transforming our basic understanding of polypore diversity and natural history. We integrated over 40,000 historical and modern records of polypores in Estonia (hemiboreal Europe), revealing 227 species, and including Polyporus submelanopus and P. ulleungus as novelties for Europe. Taxonomic and conservation problems were distinguished for 13 unresolved subgroups. The estimated species pool exceeds 260 species in Estonia, including at least 20 likely undescribed species (here documented as distinct DNA lineages related to accepted species in, e.g., Ceriporia, Coltricia , Physisporinus , Sidera and Sistotrema ). Four broad ecological patterns are described: (1) polypore assemblage organization in natural forests follows major soil and tree-composition gradients; (2) landscape-scale polypore diversity homogenizes due to draining of peatland forests and reduction of nemoral broad-leaved trees (wooded meadows and parks buffer the latter); (3) species having parasitic or brown-rot life-strategies are more substrate-specific; and (4) assemblage differences among woody substrates reveal habitat management priorities. Our update reveals extensive overlap of polypore biota throughout North Europe. We estimate that in Estonia, the biota experienced ca. 3–5% species turnover during the twentieth century, but exotic species remain rare and have not attained key functions in natural ecosystems. We encourage new regional syntheses on long studied fungal groups to obtain landscape-scale understanding of species pools, and for elaborating fungal indicators for biodiversity assessments.

Regional faunas are structured by historical, spatial and environmental factors. We studied large‐scale variation in four ecologically different beetle groups (Coleoptera: Dytiscidae, Carabidae, Hydrophiloidea, Cerambycidae) along climate, land cover and geographical gradients, examined faunal breakpoints in relation to environmental variables, and investigated the best fit pattern of assemblage variation (i.e. randomness, checkerboards, nestedness, evenly spaced, Gleasonian, Clementsian). We applied statistical methods typically used in the analysis of local ecological communities to provide novel insights into faunal compositional patterns at large spatial grain and geographical extent. We found that spatially structured variation in climate and land cover accounted for most variation in each beetle group in partial redundancy analyses, whereas the individual effect of each explanatory variable group was generally much less important in accounting for variation in provincial species composition. We also found that climate variables were most strongly associated with faunal breakpoints, with temperature‐related variables alone accounting for about 20% of variation at the first node of multivariate regression tree for each beetle group. The existence of faunal breakpoints was also shown by the ‘elements of faunal structure’ analyses, which suggested Clementsian gradients across the provinces, that is, that there were two or more clear groups of species responding similarly to the underlying ecological gradients. The four beetle groups showed highly similar biogeographical patterns across our study area. The fact that temperature was related to faunal breakpoints in the species composition of each beetle group suggests that climate sets a strong filter to the distributions of species at this combination of spatial grain and spatial extent. This finding held true despite the ecological differences among the four beetle groups, ranging from fully aquatic to fully terrestrial and from herbivorous to predaceous species. The existence of Clementsian gradients may be a common phenomenon at large scales, and it is likely to be caused by crossing multiple species pools determined by climatic and historical factors on the distributions of species.

Temperature variability is a major driver of ecological pattern, with recent changes in average and extreme temperatures having significant impacts on populations, communities and ecosystems. In the marine realm, very few experiments have manipulated temperature in situ, and current understanding of temperature effects on community dynamics is limited. We developed new technology for precise seawater temperature control to examine warming effects on communities of bacteria, microbial eukaryotes (protists) and metazoans. Despite highly contrasting phylogenies, size spectra and diversity levels, the three community types responded similarly to seawater warming treatments of +3°C and +5°C, highlighting the critical and overarching importance of temperature in structuring communities. Temperature effects were detectable at coarse taxonomic resolutions and many taxa responded positively to warming, leading to increased abundances at the community-level. Novel field-based experimental approaches are essential to improve mechanistic understanding of how ocean warming will alter the structure and functioning of diverse marine communities.

Four microhabitats within pools (cobbles, sand, leaf litter, and bank vegetation) and one microhabitat in riffles (cobbles) were sampled in both rainy and dry seasons to identify groups of caddisfly species that share larval microhabitats across 15 sites in streams in eastern Cuba. A total of 4,367 individuals representing 13 families, 22 genera, and 36 taxa (species and morphospecies) were collected. To explore the distribution of caddisfly species by microhabitat, a k-means clustering method was used. This analysis grouped the samples into seven clusters based on species abundance across microhabitats, seasonality, altitude, and stream order. The results show that caddisfly abundance is strongly influenced by microhabitat type, seasonal variation, and river characteristics. Riffles consistently had the highest abundance of caddisflies across all sampling periods. Functional feeding groups showed variable abundance and behavior. Scrapers were strongly influenced by seasonality with high abundance in the rainy season, while generalists showed no significant seasonal effect on abundance. This study provides detailed biological trait information for specific caddisfly species, which is essential for using multimetric indices to accurately determine the health of freshwater ecosystems.