ABSTRACT In oviparous species, females shape offspring phenotype during early development by varying the resources they deposit in the egg prior to laying. Yolk androgen levels, for example, vary within and among females and their deposition is influenced by maternal state, as well as environmental conditions, including the social environment. By providing artificial breeding sites, such as rooftops, urbanisation has created novel breeding contexts for Herring gulls, which, however, differ from a traditional ground‐breeding context in several ecological characteristics that may influence yolk androgen deposition. Here, we compared yolk testosterone concentrations in the last‐laid egg of rooftop‐ and ground‐breeding Herring gulls across two breeding seasons and tested whether variation was associated with social environment (approximated by nest density) or maternal quality differences (reflected by egg volume, laying date of the last egg and diet composition). Rooftop‐breeding pairs showed higher yolk testosterone concentrations than ground‐breeding pairs in 2023, while no difference was observed in 2024. Ground‐breeding pairs also exhibited significant interannual variation, whereas rooftop pairs did not. Neither nest density nor any proxy of maternal quality explained variation in yolk testosterone levels. These results indicate that yolk testosterone allocation in Herring gulls is variable but not consistently explained by breeding context, social environment or maternal state.
ABSTRACT Ecotones are transition zones that integrate environmental gradients and play an important role in biodiversity conservation; however, within the context of South Korea, their ecological functions and spatial characteristics remain insufficiently quantified at the national scale. Scientific evidence is needed to support their inclusion in protected area planning. In this study, we quantified the spatial distribution and ecological characteristics of ecotone zones (EZs) across vegetation–climate zones in the temperate forests of South Korea and examined their associated biodiversity patterns and species turnover. Entropy‐based spatial classification was conducted to delineate the EZs. Environmental and compositional differences among zones were tested using ANOVA and multivariate ordination (CCA, MRPP), while species turnover and community‐assembly processes were examined through zeta‐diversity–based model comparisons (RMSE, AIC). The EZs exhibited mixed characteristics of multiple vegetation–climate zones, showing intermediate environmental conditions and transitional species composition consistent with a buffering role. EZs showed high species richness (607.8 ± 9.6 species per grid) that did not differ significantly from the Northern Temperate Zone (NTZ) (p = 0.069), and CCA explained the compositional gradient, with the first two axes accounting for 86.5% of the constrained variance (CCA1 = 57.2%, CCA2 = 29.3%). MRPP results indicated the greatest compositional overlap between EZ and the Central Temperate Zone (A = 0.0317), the lowest agreement value among all pairwise comparisons. The zeta‐diversity analysis revealed unimodal patterns with intermediate turnover and partial stability dominated by stochastic processes. These patterns indicate that EZs are transition zones associated with high species richness and intermediate turnover. Overall, our findings suggest that EZs may warrant consideration in protected‐area prioritization and provide a quantitative basis for identifying them at the national scale.
ABSTRACT The Mongolian Plateau, a typical arid and semi‐arid zone in Eurasia, is characterized by highly heterogeneous and fragmented wetland habitats. Phragmites australis, a common wetland species in this region, exhibits remarkable adaptability. Unraveling the coordination between phylogenetic history and local environmental filtering is crucial for elucidating its adaptive mechanisms. Integrating landscape genomics and trait‐based phylogenetic analyses, we analyzed transcriptome‐wide SNPs, multidimensional functional traits, and environmental variables across 90 individuals from 30 natural P. australis populations. This study aims to reveal the genetic and phenotypic variation patterns underlying population genetic structure and trait variation, specifically distinguishing the roles of geographic isolation, environmental filtering, and phylogenetic history. Results reveal a significant drainage‐dependent pattern in genetic structure. Populations in hydrologically connected basins show extensive admixture, whereas those in isolated endorheic basins form distinct lineages. While geographic isolation underpins genetic differentiation, environmental filtering independently explains ~33.84% of the genetic variation, driven primarily by moisture heterogeneity (precipitation seasonality and soil moisture). Crucially, we observed differentiated evolutionary trajectories across functional traits. Structural traits (e.g., plant height, leaf thickness) are phylogenetically conserved; in contrast, physiological traits (e.g., water use efficiency) are decoupled from phylogeny, showing patterns consistent with high plasticity regulated by local environments. This evolutionary decoupling strategy enables P. australis to flexibly adapt to heterogeneous habitats while maintaining structural stability. This study uncovers the synergistic mechanisms by which geographic isolation and environmental filtering jointly shape the genetic patterns of this cosmopolitan species at a regional scale, clarifies that its evolutionary responses may depend heavily on the differentiated plasticity of trait types, and provides valuable regional insights into how widespread wetland species adapt to heterogeneous environments under global change.
ABSTRACT Studying historical dynamics and compositional changes of ecotones is essential for improving predictions of their responses to anthropogenic global change. However, the small size and geographic isolation of marginal ecotonal stands require retrospective analyses at the local scale. Here, we combine soil macrofossil charcoal analysis (SMCA), a lake‐sediment pollen record, and contemporary forest inventories to reconstruct past dynamics and assess contemporary trajectories of forest stands located at the northern boundary of the boreal‐temperate ecotone (BTE) in the Rimouski hinterland (Lower St. Lawrence region, Canada). Radiocarbon‐dated soil charcoal particles and regional pollen data reveal a delayed local establishment of thermophilous species, such as white pine (Pinus strobus), toward the end of the Holocene Climatic Optimum. This lagged expansion of temperate taxa coupled with a decline of boreal conifers led to the development of thermophilous assemblages that persisted into the early Neoglacial despite climatic cooling. Borealization of the landscape did not begin until the late Neoglacial (⁓1500 cal year BP), coinciding with shifts in the fire regime and the arrival of the eastern white cedar (Thuja occidentalis). At the stand‐scale, comparisons among charcoal assemblages in buried and surface soil layers with dead and living trees reveal an unprecedented proliferation by trembling aspen, as well as a recent establishment of jack pine likely reflecting anthropogenic disturbances associated with European settlement. However, current size‐class distribution suggests that these recent changes are likely to be transient in the absence of recurrent disturbances. Although predictive modeling remains necessary to forecast future forest trajectories under climate change, our results underscore the value of multi‐proxy reconstructions for disentangling vegetation responses to interacting climate and disturbance drivers.
ABSTRACT The supraglacial environment represents a unique habitat that harbors overlooked biodiversity, which is increasingly threatened by climate warming but remains underexplored. This study aims to investigate bacterial and fungal distribution patterns on five debris‐covered glaciers from two typical mountain ranges dominated by a monsoon climate (Mt. Gongga and Mt. Gangrigabu). High‐throughput amplicon sequencing of the bacterial 16S rRNA gene (V3–V4 region) and the fungal ITS region was performed using the Illumina MiSeq platform. Despite harsh and nitrogen‐limited conditions, the supraglacial debris across two mountain ranges supported phylogenetically diverse microbial taxa. Dominant bacterial families included Sphingomonadaceae, Chitinophagaceae, and Comamonadaceae, while dominant fungal families included Thelephoraceae, Mortierellaceae, and Inocybaceae, highlighting the establishment of specialized microbial assemblages in oligotrophic glacier surface environments. Compared with Mt. Gongga, supraglacial debris from Mt. Gangrigabu exhibited significantly lower bacterial alpha diversity, likely driven by environmental filtering associated with higher pH and total carbon content. In contrast, fungal alpha diversity showed limited regional variation. Notably, we observed a significant “distance decay” pattern in both bacterial and fungal communities, which illustrated a decline in taxonomic similarity with increasing geographic distance across glaciers, particularly pronounced in bacterial communities (R = −0.70, p < 0.001). Microbial community composition exhibited stronger glacier‐specific differentiation, heterogeneous environmental selection emerged as the dominant ecological process shaping microbial turnover across isolated glaciers, with pH and carbon content playing dominant roles in shaping microbial community variation. Our cross‐range comparison reveals that deterministic environmental filtering among geographically isolated glaciers governs the spatial turnover in supraglacial microbial communities, providing new insights into the ecological mechanisms governing microbial biogeographic patterns in rapidly changing cryospheric ecosystems across the southeastern Tibetan Plateau.
ABSTRACT The study of functional trait variation is increasingly used to understand macrophyte adaptation, as traits reflect organismal performance under different ecosystem conditions. Phenotypic expression results from the interplay of genetic and environmental factors: genetics provides the molecular basis for heritable traits and constrains potential phenotypes, while the environment acts as a selective and modulatory force. However, the genetic insight into traits has rarely been addressed in freshwater macrophyte studies. This review examines the different ways in which the DNA of macrophytes interplays with the environment and contributes to the variation in their functional traits, outlining main approaches, gaps, and future challenges. Only 21 studies explicitly combined genetics with functional traits and environment in the last fifteen years. The most common approach was the use of common garden experiments to explore acclimation and adaptation in a few model species. Current studies mainly focus on morphological and growth traits that best describe macrophytes' economic strategies, with limited attention to other trait categories, while the genetic and DNA traits studied are more variable. Across studies, environmental factors generally explained a larger proportion of functional trait variation, highlighting the dominant role of phenotypic plasticity for macrophyte acclimatation, whereas genetic contribution increased under experimentally manipulated conditions. Genome size and epigenetic variation influenced phenotypic plasticity; however, the effect was different and inconsistent on traits and depended on phylogenetic relationships and geographical environment variation. In field studies of natural populations, life history traits and hydrology had a strong effect on the geographic distribution of genetic diversity and the response to selection, as well as on our ability to distinguish selection from genetic drift. Future research should enhance molecular analyses, adopt multifactorial and long‐term experimental designs, develop conceptual frameworks to address the relationships between genomics, environment and functional traits and integrate emerging tools to capture macrophyte adaptation better.
ABSTRACT The increasing global habitat fragmentation has led to a marked decline in landscape connectivity, posing a severe threat to biodiversity. However, our understanding of how landscape connectivity influences biodiversity, particularly for plant diversity, remains notably limited. Taking the meadow of Poyang Lake as a case and comprehensively considering the ecological processes of water level change and species dispersal, this study firstly applied the landscape pattern metrics and the graph‐theoretic connectivity metrics to measure the dynamics of meadow structural connectivity and functional connectivity after identifying the spatial distribution of meadow at different water levels. Then, the effects of meadow connectivity on plant diversity and its scale effects were revealed through the linear regression model (LRM), and the redundancy analysis (RDA) was used to explore the contrasted explanatory of meadow structural connectivity and functional connectivity to plant diversity patterns. The results showed that: (1) Meadow was inundated and divided by water and its shrinkage coexisted with fragmentation when the water level rose. While meadow emerged and spliced and its expansion co‐occurred with cohesion when the water level fell. (2) When the water level increased, the shape of patch simplified, the area of patch shrank, the density of patch reduced, the aggregation of patch decreased and the meadow structural connectivity decreased progressively. Meanwhile, the number of components rose, the possibility of connectivity decreased and the meadow functional connectivity reduced dramatically. (3) Higher meadow connectivity not only led to greater plant species richness (α diversity) at the landscape scale but also increased plant community similarity (i.e., low β diversity) at the patch scale. Functional connectivity explains plant diversity patterns better than structural connectivity. This thesis proposes a new perspective of landscape connectivity for biodiversity conservation and landscape pattern optimization in lake areas.
ABSTRACT Accurate species identification is essential for effective management of threatened species, especially those with overlapping distributions and similar morphologies. Skate (Order Rajiformes) exhibit a highly conserved superficial morphology, which has resulted in a long history of taxonomic confusion and misidentification within this group. The flapper skate (Dipturus intermedius) and common blue skate (D. batis) are prime examples of this challenge; both species inhabit the Northeast Atlantic and share a complicated, intertwined taxonomic history. Given their overlapping distributions, precise species identification is necessary to ensure targeted management actions. Despite the availability of reliable morphological keys for larger specimens, identification of juveniles remains challenging because many diagnostic features are underdeveloped or obscured by damage. This study aimed to identify additional traits for differentiating juvenile (< 100 cm) flapper and common blue skate by employing morphological approaches validated through molecular techniques. The analysis focused on identifying distinct features that remain detectable in damaged specimens, ensuring the method's practical applicability in field conditions. We identified four robust features that can be used to differentiate juveniles of the two species: ventral coloration, disc shape, anterior disc margin shape and rostrum shape. The findings presented here enhance data accuracy for juvenile flapper and common blue skates, support targeted conservation actions, and contribute to the effective management and long‐term recovery of these threatened species.
Anthropogenic disturbances to forests have reduced densities of tree cavities and potentially led to declines in the abundance of cavity-dependent mammals. Artificial cavities (nest boxes, carved and drilled cavities) may be used to restore habitat quality that may otherwise take many decades to recover naturally. We investigated whether artificial cavities could support populations of two species of Australian cavity-dependent mammals, the brush-tailed phascogale (Phascogale tapoatafa, 200 g) and the inland sugar glider (Petaurus notatus, 110 g). This is the first detailed study of non-flying mammals that has attempted to do this. We censused animals twice per year over 6 years in 164 nest boxes arranged in 74 clusters through a 600-ha forest block deficient in tree cavities. We addressed four key questions: (1) were nest boxes used by a large number of individuals of the target species, (2) was use sustained over multiple years, (3) were nest boxes used for breeding and (4) what proportion of the local population might be supported by the nest boxes? We detected up to 58 adult phascogales and 232 adult sugar gliders in our boxes. Use was sustained over time with a mean probability of occupancy per cluster per year of 0.66 in the phascogale and 0.89 in the sugar glider. Differences in life history influenced how breeding was assessed. We detected breeding in 98% of female phascogales and at 68% of sites with sugar gliders. We estimated the total number of adults of each species that might occupy our study area based on their known spatial requirements. Our nest boxes potentially supported up to 61% of the adult female phascogales and 72% of the adult sugar gliders in the study area. Provision of shelter and breeding sites for such large segments of populations could be highly beneficial to manage populations of cavity-dependent mammals.
No systematic comparison of DNA extraction strategies exists for minute Vertiginidae (shell height < 3 mm), a group posing a dual analytical challenge: extremely low tissue input and co-purified PCR-inhibitory mucus. For legally protected species, an additional requirement to preserve the shell voucher further constrains available protocols. Using Vertigo antivertigo as the model species, we compared six approaches applied to specimens preserved in 96% ethanol (n = 10 per method): two HotSHOT alkaline-lysis protocols (destructive and non-destructive shell-preserving variants), a modified CTAB protocol supplemented with PVP-40 and DTT, and three commercial silica-column kits (GeneJET Genomic, DNeasy Blood & Tissue, QIAamp DNA Micro). DNA yields were quantified by QuantiFluor fluorometry, and PCR performance was subsequently assessed across four loci (COI barcode, COI mini-barcode, ITS1, ITS2). DNeasy Blood & Tissue produced the highest fluorometric concentrations; QIAamp DNA Micro and CTAB + PVP-40 gave intermediate values. The shell-preserving HotSHOT variant yielded lower concentrations but improved A260/230 ratios. BSA and trehalose supplementation increased PCR success in inhibition-prone HotSHOT extracts from 70% to 100%. ITS1 Sanger sequencing of three Vertigo species listed in Annex II of the EU Habitats Directive, all extracted with the shell-preserving protocol, confirmed species-level identification (99.8%-100% BLASTn identity; mean Phred Q > 51). The shell-preserving non-destructive HotSHOT protocol yields sequenceable DNA from protected Vertiginidae while retaining the morphological voucher, making it the preferred option for conservation-genetic monitoring. The practical decision framework documented here-integrating voucher preservation, amplification robustness and per-sample cost-has broad applicability to other minute terrestrial gastropods processed in large-scale biodiversity surveys.
Habitat fragmentation is widely expected to reduce population connectivity and increase genetic differentiation, although the strength of these effects depends on species-specific traits such as dispersal ability. Here, we investigated the population genetic structure of the cosmopolitan butterfly, Pieris rapae L. (Lepidoptera: Pieridae), across western Germany using genome-wide single-nucleotide polymorphism (SNP) data. To analyze the effects of landscape structure on genetic connectivity, we applied a paired study design comprising four landscape pairs, each consisting of a highly intensified, modern agricultural landscape and a more heterogeneous, traditional landscape. Our results revealed no evidence of genetic differentiation. Pairwise FST values were close to zero; we detected no isolation by distance, and clustering analyses supported a single genetic population. No meaningful associations between genetic variation and environmental variables were detected, with landscape effects explaining less than 0.4% of genomic variation. Consequently, we found no evidence for stronger genetic structuring in modern compared to more connected traditional landscapes. Our results suggest that extensive habitat fragmentation does not necessarily translate into reduced genetic connectivity in highly mobile, generalist species. In P. rapae , high dispersal ability and ecological generalism appear to buffer against the genetic consequences of landscape modification, resulting in panmictic population structure even across strongly contrasting agricultural landscapes.
ABSTRACT In order to ensure the effective conservation of the critically endangered European hamster (Cricetus cricetus), there is a necessity for the implementation of targeted conservation measures and reliable monitoring methods. This study explores the potential of employing Deep Learning (DL) to assist with camera trap monitoring for the purpose of tracking hamster activity. To this end, an object detection model (YOLO) was trained to efficiently analyze large volumes of video data from summer 2023 with high reliability. The model achieved a weighted average F1‐score of 0.93 and an accuracy of 0.93 for the detection of European hamsters, effectively differentiating them from other species. A comparison between DL‐based and human evaluations confirmed that DL can reliably depict hamster activity patterns. The findings of this study suggest that European hamsters exhibit peak activity levels at dusk, with the highest peak in activity occurring around sunset. In contrast, activity levels were lowest around midday. Autocorrelation analysis revealed a biphasic activity pattern, with a secondary peak occurring approximately before sunrise. This study underscores the potential of employing DL for long‐term conservation efforts and its applicability in assessing the success of reintroduction programs.
ABSTRACT Neoniphon argenteus, a widely distributed nocturnal coral reef fish in the family Holocentridae, plays an important role in maintaining coral reef ecosystem health, yet its phylogenetic position remains poorly resolved. To bridge this gap, we sequenced and analyzed the complete mitochondrial genome of a specimen from the South China Sea to characterize its structural features, codon usage patterns, and phylogenetic relationships. The 16,569 bp mitogenome (GenBank: PP190474.1) encodes 13 protein‐coding genes (PCGs), 22 tRNAs, two rRNAs, and two non‐coding regions, exhibiting a distinct A + T bias. All tRNAs fold into typical cloverleaf secondary structures except tRNA‐Ser (AGN), which lacks the dihydrouridine (DHU) arm. The control region contains palindromic motifs (TACAT/ATGTA) capable of forming hairpin structures and five conserved sequence blocks, whereas the OL region harbors a conserved 5′‐GCCGG‐3′ motif. RSCU analysis revealed 31 frequently used codons (RSCU > 1) with a pronounced preference for A/C‐ending codons. The ΔRSCU method identified 10 candidate optimal codons (GCA, CAA, GAA, GGA, AUU, CUA, CCA, CGA, ACA, and GUC). Selection pressure analysis using EasyCodeML and site‐specific models indicated that all PCGs are predominantly under purifying selection, with no significant evidence of pervasive positive selection. ND6 exhibited elevated pairwise Ka/Ks ratios (mean = 1.209 ± 0.047), consistent with reduced selective constraint rather than adaptive evolution. Phylogenetic analysis of 19 Holocentriformes species using maximum likelihood and Bayesian inference with partitioned models based on 13 PCGs and two rRNA genes (12S and 16S) assigned all taxa to two well‐supported subfamilies (Holocentrinae and Myripristinae). Within Holocentrinae, Neoniphon species form a monophyletic clade nested within a paraphyletic Sargocentron, suggesting that the genus Sargocentron as currently defined is not monophyletic. This study provides useful baseline molecular data for further exploration of the evolutionary history of N. argenteus and other members of Holocentriformes.
ABSTRACT A core component of conservation management projects is the estimation and monitoring of abundance of target species, in space and through time. Monitoring wildlife is complicated and relies on detection, which itself depends on environmental conditions, phenotypes and behaviours of the species being monitored. Aldabra giant tortoises (Aldabrachelys gigantea) have great importance as ecosystem engineers, keystone species and ecological replacements. Accurate monitoring is vital to understanding both the size and dynamics of their native and translocated populations, and the species' influence on the wider ecosystem. Despite a long history of organised research and population surveys in their native range on Aldabra Atoll in the Seychelles, to date no rigorous, atoll‐wide estimation of giant tortoise population size has been attempted. The complexity of irregular transect surveys, through a variety of habitats, in several areas of the atoll, necessitates the use of state‐space statistical models that capture heterogeneities in both abundance and detection. Here we develop a Bayesian Hierarchical Distance Sampling (HDS) model to infer habitat‐ and season‐dependent detectability and abundance of the Aldabra giant tortoise population on Aldabra. Between 2018 and 2021 the population was apparently relatively stable and numbered approximately 180,000 individuals, the highest estimate so far made for this population. We attribute this stability and high abundance to the extended history of conservation efforts on Aldabra, including invasive alien species eradication which should be maintained and expanded. We provide a reproducible workflow for Bayesian distance sampling methods using data‐augmentation and habitat‐dependent detectability and recommend its use on legacy datasets and future abundance surveys for similar species. These methods enable robust inference of abundance and detectability even when data are irregular or inconsistently collected, providing a framework for integrating legacy datasets with modern conservation workflows.
ABSTRACT The Changbai Mountain range is one of the key glacial refugia in Northeast Asia. Mesenchytraeus exhibits high species diversity, strong endemism, and widespread cryptic species in this region, for which mitogenomes provide useful molecular markers for exploring cryptic species complexes. This makes Mesenchytraeus an ideal model for studying mitogenome evolution among closely related lineages; however, no mitogenome data have been reported for this genus to date. In this study, we performed de novo assembly, annotation, and comparative analysis of the mitogenomes of 13 Mesenchytraeus species (14 individuals) from Changbai Mountain. All mitogenomes are typical circular molecules containing 37 genes, but putative control regions are rearranged and consistently located between ATP6 and trnR. All species exhibit annelid‐specific strand nucleotide biases, characterized by negative GC skew and near‐zero AT skew. Codon usage analysis reveals that codon families with wobble U are significantly biased toward mtDNA codons, whereas those with wobble C or G are biased toward non‐mtDNA codons, suggesting a conserved mitochondrial codon usage pattern in annelids. All tRNAs form typical cloverleaf secondary structures except trnS2, which lacks the D‐stem and the dihydrouridine (DHU) arm in some species. The putative control regions commonly contain complex palindromic repeats, hairpins, and repetitive elements, and may harbor dual replication origins. Phylogenetic analyses support the monophyly of Mesenchytraeus and reveal significant molecular divergence among morphologically cryptic species. This study provides the first mitogenome dataset for Mesenchytraeus and offers new insights into the evolution and replication mechanisms of mitogenomes in Clitellata and broader Annelida.
ABSTRACT Plant mitochondrial genomes (mitogenomes) vary markedly in size and architecture despite generally slow rates of sequence evolution. Phoebe is an ecologically and economically valuable genus of Lauraceae, yet its mitogenome diversity remains poorly characterized. In this study, we newly sequenced, assembled, and annotated the mitogenomes of three nationally protected Class II wild plants (P. bournei, P. chekiangensis, P. zhennan) from China and compared their mitogenomic characteristics. The three assemblies were resolved into representative circular configurations ranging from 808 to 864 kb, with similar GC contents and conserved protein‐coding capacity. Each mitogenome contained distinct 41 protein‐coding genes, 27–28 transfer RNAs, and three ribosomal RNAs. Synteny analysis revealed extensive changes in homologous‐block order and orientation despite substantial sequence homology among the three species. Abundant repeats occurred predominantly in noncoding regions, while plastid‐derived fragments documented historical intracellular DNA transfer. The three species exhibited similar codon usage and predicted RNA‐editing patterns, whereas low synonymous divergence limited inference from pairwise ratios. Phylogenetic analysis based on mitochondrial protein‐coding genes recovered Phoebe as a well‐supported monophyletic lineage. These results reveal substantial structural divergence accompanied by conserved nucleotide composition and coding capacity, providing valuable data for further understanding the evolutionary variation of plant mitogenomes of Phoebe and the Lauraceae.
ABSTRACT Species abundance typically declines toward the edges of geographic ranges, while their conservation relevance increases. Habitat studies therefore often focus on only small parts of species' ranges, potentially biasing our understanding of ecological niches. Here, we compared habitat use of the Southern White Admiral (Limenitis reducta) between populations at the northern and near the southern range edge to assess whether and how habitat associations differ across the species' distribution range. The Swabian Jura represents the northern range edge, while the Turkish Aegean region lies near the southern range edge within the Mediterranean core distribution. We systematically surveyed larval stages in both regions. We compared host plant species, host plant height, site exposition, solar radiation duration at host plants, and shading by neighboring trees. In addition, the height of the larvae above ground was recorded. Host plant species differed between regions but belonged to the genus Lonicera in both. The species was associated with relatively well‐sunlit sites in both regions, reflected by preferences for host plants receiving high solar radiation and low shading by neighboring trees. These associations were markedly stronger at the northern range edge. Larvae were found higher above ground at the northern range edge, and species occurrence was positively associated with host plant height in both regions. Regional differences in habitat associations indicate differences in realized microhabitat use between regions with contrasting macroclimatic conditions. The stronger association with highly sun‐exposed habitats at the northern range edge is consistent with the hypothesis that habitat use is more strongly constrained under cooler climatic conditions than near the southern range edge. These findings highlight the importance of considering multiple parts of a species' geographic range when assessing habitat associations and developing conservation strategies under changing climatic conditions.
ABSTRACT DNA barcoding is a highly effective tool for species identification, complementing taxonomic and phylogenetic studies while also playing a key role in biomonitoring and uncovering cryptic diversity. Techniques such as DNA barcoding, metabarcoding and environmental DNA (eDNA) analysis are widely applied in biodiversity conservation, tracking invasive species and studying trophic interactions. To carry out this type of research effectively, a robust DNA barcode library is essential, built upon high‐quality genetic sequences and accurate taxonomic identification. Here, we present the results of a large‐scale DNA barcoding study of Polish diplopod species (Myriapoda: Diplopoda), providing an up‐to‐date checklist of species recorded in Poland and a reference DNA barcode library. We deliver data on 981 individuals identified to species level, of which 468 have COI sequence data. 58 out of 93 species recorded for Poland were successfully barcoded, representing 62% of the national fauna. Additionally, we explore future research directions, potential cryptic diversity and shifts in the national fauna, including newly recorded species for Poland—Melogona broelemanni (Verhoeff, 1897). Our findings highlight the significance of ongoing monitoring and molecular methods in tracking biodiversity changes.
Area of occupancy (AOO) is a widely used metric for assessing species' vulnerability. To standardize AOO estimation, the IUCN recommends using a fixed 2 × 2 km grid. However, for species represented by sparse and irregular records, this resolution can substantially underestimate AOO. Although spatial modeling offers a potential solution, model-based estimates may differ among taxa and studies depending on data structure, predictor choice, and modeling strategy. In this paper, we present a reproducible workflow that uses breakpoint analysis of record-accumulation curves to identify informative species-specific grid sizes and to estimate AOO from incomplete occurrence records. We applied this framework to 13 snake species found in Georgia, with diverse ecological characteristics within a topographically complex, irregularly sampled region. Repeated subsampling of the six best-represented species showed that accumulation-curve predictions were more accurate than raw occupied-cell counts in 96%-98% of comparisons. Nine of the 13 species showed significant breakpoint-derived scales between approximately 4 and 13 km rather than at the standard 2 km resolution. This workflow offers a practical way to explore scale dependence, sampling incompleteness, and sensitivity of AOO estimates derived from historical and citizen-science occurrence datasets. The workflow complements the standardized 2 × 2 km AOO used in formal IUCN Red List assessments.
Niche overlap is widely used to study species coexistence and biodiversity patterns. However, because macroclimatic niches are typically estimated from species distributions, relationships between niche overlap and geographic range overlap may partly reflect the shared structure of environmental and geographic space rather than ecological processes. Here, we address this challenge by constructing the BioOverlap database combining IUCN range maps and bioclimatic variables to quantify macroclimatic niche properties, niche overlap, and geographic range overlap among ~16,000 terrestrial and marine species, yielding ~90 million pairwise comparisons. Using a taxonomically structured subset encompassing eight taxonomic groups with consistently available variables, we addressed two objectives. First, we quantified niche originality (i.e., the distinctiveness of a species' niche relative to other species), and identified its ecological and evolutionary determinants. Second, we used structural equation modeling integrating niche and range attributes to test whether relationships between niche and range overlap among sympatric species deviate from null expectations. Niche originality showed consistent associations with ecological variables including niche breadth, climatic heterogeneity, species richness and productivity, whereas phylogenetic isolation had limited influence. In contrast, across most sympatric taxa, the positive association between niche and range overlap was indistinguishable from null expectations, with deviations observed only in birds, Chondrichthyes, and marine fishes. This suggests that relationships between niche and range overlap estimated from distribution data may arise largely from the shared structure of species distributions and environmental space rather than from ecological structuring. Explicit null model comparisons are therefore essential when interpreting niche-range relationships and suggest that independently estimated niches (e.g., from experimental data) may be necessary to distinguish genuine ecological signal. Together, these results establish BioOverlap as a valuable global resource for investigating large-scale biodiversity patterns and niche structure across taxa, while providing a framework for benchmarking niche-based relationships against appropriate null expectations.
