Functional Diversity Research Articles

Acoustic indices fail to represent different facets of biodiversity

Acoustic indices are cost-efficient tools for monitoring acoustically active taxa. Despite their increasing popularity, their suitability as biodiversity proxies remains debated due to theoretical and practical issues. Existing research has predominantly focused on assessing their capacity to capture species richness and abundance of sounds, with limited attention given to other biodiversity facets like phylogenetic and functional diversity. Yet, phylogenetic distance and trait diversity may influence acoustic communication, so acoustic indices may be better suited to capture their changes than changes in the mere number of species. Here, we investigated the ability of acoustic indices to represent the species, phylogenetic, and functional diversity of acoustically active avian species across three habitat types in Italy: urban, riparian forest and deciduous woodland.Recordings were collected at dawn by a trained ornithologist, who also identified acoustically active species captured, first in the field and secondarily from recordings. We then applied eleven widely used acoustic indices for each recording and tested their ability to capture differences in species, functional and phylogenetic diversity across sites (i.e., listening points) within each habitat type using a linear mixed effect model. We then reduced the acoustic indices dimensionality to a few axes and repeated the analysis to test if compound indices delivered comparable information.Species richness and phylogenetic diversity correlated with at least one acoustic index across the three habitat types, while functional diversity correlated with an index only in the urban habitat. However, the nature of the relationships identified was often opposite to what expected by the indices’ formulation. Furthermore, across the three habitat types the interrelations among indices varied, as well as the observed relationships with diversity indices. Compound indices also exhibited inconsistent relationships across sites and contrary to what expected based on their correlation with acoustic indices.Our results cast doubts on the suitability of acoustic indices as proxies for biodiversity for biodiversity monitoring. Additionally, the inconsistent relationship among indices across the three areas suggests they are unsuitable for geographic comparisons. Temporal comparisons are possible but require local validation and may need adjustments over time of the community composition changes. Despite the attractiveness of acoustic indices as easy and cheap tools for biodiversity monitoring, we urge caution on their application.

Targeting Histamine and Histamine Receptors for Memory Regulation: An Emotional Perspective.

Histamine has long been accepted as a pro-cognitive agent. However, lines of evidence have suggested that the roles of histamine in learning and memory processes are much more complex than previously thought. When explained by the spatial perspectives, there are many contradictory results. However, using emotional memory perspectives, we suspect that the histaminergic system may interplay with stress, reward inhibition, and attention to modulate emotional memory formation. The functional diversity of histamine makes it a viable target for clinical management of neuropsychiatric disorders. Here, we update the current knowledge about the functions of histamine in emotional memory and summarize the underlying molecular and neural circuit mechanisms. Finally, we review the main clinical studies about the impacts of histamine-related compounds on memory and discuss insights into future research on the roles of histamine in emotional memory. Despite the recent progress in histamine research, the histaminergic emotional memory circuits are poorly understood, and it is also worth verifying the functions of histamine receptors in a more spatiotemporally specific manner.

PaRaVis: An automatic Python graphical package for ensemble analysis of plant beta diversity using remote sensing proxies

The ongoing impacts of climatic changes, coupled with intensified human activities, are leading to a significant loss of plant diversity, prompting urgent calls for comprehensive monitoring of forest ecosystems. This is particularly concerning in regions with the encroachment of human activities into forest zones, and inadequate regulations that primarily view forests as a source of timber without fully accounting for their critical roles in biodiversity. These issues highlight the need for effective geospatial approaches to support conservation strategies and sustained monitoring of plant diversity. The majority of remote sensing studies of plant diversity have focused on alpha-diversity, while beta-diversity plays an important role in providing a comprehensive picture of biodiversity patterns across scales. Among various remote sensing proxies, Rao's Q index stands out as a reliable metric to quantify beta-diversity using multispectral remote sensing indices. However, a holistic approach that can incorporate multiple remote sensing indices and enable comparative analysis using graphical means with computational efficiency is lacking. In response, we developed PaRaVis, an open-source Python-based graphical package for deriving spectral diversity from multispectral remote sensing datasets as a proxy for functional diversity using Rao's Q index. This tool encompasses all the necessary steps for parallelized computation, visualization, and analysis of Rao's index from either single or multiple multispectral indices. It is capable of calculating and visualizing 75 vegetation indices (VIs), from a raster scene, followed by calculating Rao's Q both unidimensionally and multidimensionally in parallel. PaRaVis also offers features for visualizing, analyzing, and comparing Rao's Q outputs using statistical performance diagnostics. It provides a unique means to infer diversity patterns in space and time and is therefore invaluable for researchers or organizations involved with plant diversity monitoring, especially those with limited data analysis or computer programming experience. To demonstrate the tool's effectiveness, we analyzed plant diversity patterns using satellite-derived spectral heterogeneity measures in forest sites within the Hyrcanian Forests of Iran and sites located in Germany. The first case study focused on UNESCO Natural Heritage sites. Our analysis revealed that employing EVI, SR3, and TCI indices as inputs for the multidimensional Rao's Q yielded higher performance in monitoring more heterogeneous forests compared to the unidimensional mode. In the second case study, we utilized field Species Richness and Shannon-Wiener diversity indices to evaluate PaRaVis and our method. We found that using a multi-temporal, multi-index approach enhances the results compared to multi-seasonal and classical Rao based on single time.

Herbarium collections remain essential in the age of community science.

The past decade has yielded more biodiversity observations from community science than the past century of traditional scientific collection. This rapid influx of data is promising for overcoming critical biodiversitydata shortfalls, but we also have vast untapped resources held in undigitized natural history collections. Yet, the ability of these undigitized collections to fill data gaps, especially compared against the constant accumulation of community science data, remains unclear. Here, we compare how well community science (iNaturalist) observations and digitized herbarium specimens represent the diversity, distributions, and modeling needs of vascular plants in Canada. We find that, despite having only a third as many records, herbarium specimens capture more taxonomic, phylogenetic, and functional diversity and more efficiently capture species' environmental niches. As such, the digitization of Canada's 7.3M remaining specimens has the potential to more than quintuple our ability to model biodiversity. In contrast, it would require over 27M more iNaturalist observations to produce similar benefits. Our findings indicate that digitizing Earth's remaining herbarium specimens is likely an efficient, feasible, and potentially critical investment when it comes to improving our ability to predict and protect biodiversity into the future.

Varying patterns of taxonomic and functional plant composition and diversity across different types of urban and rural grasslands

AbstractSemi‐natural grasslands are found predominantly in agricultural landscapes; however, their counterparts are also found in cities, referred to as urban grasslands. We sampled the most extensive patches of urban grasslands in Wrocław (Poland, Europe) in urban parks and along a river valley. We compared urban grasslands to broadly defined rural grasslands in terms of compositional gradients and both taxonomic and functional diversity. We also tested for relationships between rare species and different facets of diversity. Urban grasslands corresponded to three rural grassland habitat types: mesic pastures, mesic meadows, and alluvial meadows. We conducted analogous analyses, including and excluding habitat‐level assignment, to determine if emerging patterns between rural and urban grasslands are habitat‐dependent. Rural pastures and their urban counterparts showed high taxonomic and functional similarity, implying that short‐ and frequent‐cutting, applied in cities, mimics grazing management on agricultural sites. Rural mesic hay grasslands and alluvial meadows showed high taxonomic and functional dissimilarities from their urban counterparts. We found that rare species contribute to taxonomic diversity while only affecting functional diversity in a few cases. Varying patterns of taxonomic and functional similarity were observed across different habitats. Comparisons of grasslands without regard for habitat types mask diverging patterns in taxonomic and functional diversity. Despite high environmental and management pressures in urban areas (higher nutrient levels and temperatures, decreased moisture, and intensified management and soil disturbances), we showed that urban grasslands hold a considerable portion of the plant diversity found in rural grasslands.

Deciphering macrobenthic biological traits in response to long-term eutrophication in Xiangshan Bay, China.

As an emerging global issue in coastal marine ecosystems, eutrophication may lead to profound ecological consequences or disasters. Six locations in Xiangshan Bay were sampled during 2012-2022 along the eutrophication gradient from the innermost bay with the most eutrophication to the outer bay with the least eutrophication. A trait-based method was adopted to explore the ecological effects of eutrophication on macrobenthic communities. The results showed that the community composition is mostly characterized by deposit feeders and predators with small (1-3cm) and large (> 10cm) body sizes, classified as indifferent and tolerant species (AMBI ecological groups), deposit feeders and predators (feeding mode), and a preference for a free living lifestyle. The RLQ and fourth-corner analyses further confirmed that there was a negative correlation between the abundance of small macrobenthic organisms (< 1cm) and nitrate concentration. Phosphorus was a crucial influencing factor for macrobenthic spatial patterns and was strongly affected by the activities of deposit feeders and the decomposition of macrobenthos. Due to mass organic deposition resulting from increased primary production, long-term eutrophication had led to an increase in the proportion of detritus feeders. In addition, the significant negative correlation between the concentration of dissolved oxygen and first-order opportunistic species represented by the polychaete Capitella capitata indicated tolerance to hypoxia. The macrobenthic community in Xiangshan Bay had been negatively affected but maintains considerable stability in functional diversity and functional redundancy under the influence of long-term eutrophication.

Polar Interactions between Substrate and Flavin Control Iodotyrosine Deiodinase Function.

Flavin cofactors offer a wide range of chemical mechanisms to support a great diversity in catalytic function. As a corollary, such diversity necessitates careful control within each flavoprotein to limit its function to an appropriate subset of possible reactions and substrates. This task falls to the protein environment surrounding the flavin in most enzymes. For iodotyrosine deiodinase that catalyzes a reductive dehalogenation of halotyrosines, substrates can dictate the chemistry available to the flavin. Their ability to stabilize the necessary one-electron reduced semiquinone form of flavin strictly depends on a direct coordination between the flavin and α-ammonium and carboxylate groups of its substrates. While perturbations to the carboxylate group do not significantly affect binding to the resting oxidized form of the deiodinase, dehalogenation (kcat/Km) is suppressed by over 2000-fold. Lack of the α-ammonium group abolishes detectable binding and dehalogenation. Substitution of the ammonium group with a hydroxyl group does not restore measurable binding but does support dehalogenation with an efficiency greater than those of the carboxylate derivatives. Consistent with these observations, the flavin semiquinone does not accumulate during redox titration in the presence of inert substrate analogues lacking either the α-ammonium or carboxylate groups. As a complement, a nitroreductase activity based on hydride transfer is revealed for the appropriate substrates with perturbations to their zwitterion.

Spatial patterns of congruence or mismatch between taxonomic, functional, and phylogenetic diversity and endemism of perennial flora along the aridity gradient of Chile

Spatial patterns of congruence or mismatch between taxonomic, functional, and phylogenetic diversity and endemism of perennial flora along the aridity gradient of Chile

Genetic control over biogenic crystal morphogenesis in zebrafish.

Organisms evolve mechanisms that regulate the properties of biogenic crystals to support a wide range of functions, from vision and camouflage to communication and thermal regulation. Yet, the mechanism underlying the formation of diverse intracellular crystals remains enigmatic. Here we unravel the biochemical control over crystal morphogenesis in zebrafish iridophores. We show that the chemical composition of the crystals determines their shape, particularly through the ratio between the nucleobases guanine and hypoxanthine. We reveal that these variations in composition are genetically controlled through tissue-specific expression of specialized paralogs, which exhibit remarkable substrate selectivity. This orchestrated combination grants the organism with the capacity to generate a broad spectrum of crystal morphologies. Overall, our findings suggest a mechanism for the morphological and functional diversity of biogenic crystals and may, thus, inspire the development of genetically designed biomaterials and medical therapeutics.

PSSM-Sumo: deep learning based intelligent model for prediction of sumoylation sites using discriminative features.

Post-translational modifications (PTMs) are fundamental to essential biological processes, exerting significant influence over gene expression, protein localization, stability, and genome replication. Sumoylation, a PTM involving the covalent addition of a chemical group to a specific protein sequence, profoundly impacts the functional diversity of proteins. Notably, identifying sumoylation sites has garnered significant attention due to their crucial roles in proteomic functions and their implications in various diseases, including Parkinson's and Alzheimer's. Despite the proposal of several computational models for identifying sumoylation sites, their effectiveness could be improved by the limitations associated with conventional learning methodologies. In this study, we introduce pseudo-position-specific scoring matrix (PsePSSM), a robust computational model designed for accurately predicting sumoylation sites using an optimized deep learning algorithm and efficient feature extraction techniques. Moreover, to streamline computational processes and eliminate irrelevant and noisy features, sequential forward selection using a support vector machine (SFS-SVM) is implemented to identify optimal features. The multi-layer Deep Neural Network (DNN) is a robust classifier, facilitating precise sumoylation site prediction. We meticulously assess the performance of PSSM-Sumo through a tenfold cross-validation approach, employing various statistical metrics such as the Matthews Correlation Coefficient (MCC), accuracy, sensitivity, specificity, and the Area under the ROC Curve (AUC). Comparative analyses reveal that PSSM-Sumo achieves an exceptional average prediction accuracy of 98.71%, surpassing existing models. The robustness and accuracy of the proposed model position it as a promising tool for advancing drug discovery and the diagnosis of diverse diseases linked to sumoylation sites.

Rh(III)-Catalyzed Sequential ortho-C-H Bond Annulation and Desulfonylation of 3-Aryl-2H-benzo[e][1,2,4]thiadiazine-1,1-dioxides: Access to 1-Aminoisoquinolines.

An efficient Rh(III)-catalyzed C-H functionalization of 3-aryl-2H-benzo[e][1,2,4]thiadiazine-1,1-dioxides with diaryl and dialkyl alkynes has been developed for the first time to the synthesis of 1-aminoisoquinoline derivatives in a single step. This method involves through the formation of two C-C bonds and one C-N bond followed by desulfonylation to generate a novel series of isoquinolines in good to excellent yields. This is a direct method to produce pharmaceutically more relevant scaffolds with a high functional diversity.

Microplastics and biochar interactively affect nitrous oxide emissions from tobacco planting soil

Biochar application to amend acidified tobacco-soils can enhance tobacco quality and reduce nitrous oxide (N2O) emissions. Microplastics from agricultural mulch are commonly found in cash-crop farmland soils and, together with biochar, affect soil N2O emissions. In this study, we applied three types of microplastics (polyethylene, PE; polylactic acid, PLA; polybutylene adipate terephthalate, PBAT) and rice biochar alone or in combination to acidified tobacco planting soil in central China to investigate their effects on soil N2O emissions, soil chemical properties, nitrogen-cycle-related functional genes, and microbial functional diversity during a 35-day laboratory incubation period. Significant increases in N₂O emissions were observed with PE and PLA, which raised emissions by 15.96 % and 21.52 %, respectively. Additionally, different microplastics affected soil N₂O emissions through distinct regulatory pathways. Co-application of microplastics and biochar suppressed N2O emissions compared to microplastics alone. Biochar mitigates N2O emissions mainly by increasing the abundance of the nosZ gene. It can remediate soil contaminated by microplastics and reduce their negative impacts on the soil environment. This study provides deeper insight into the effects of microplastics on soil nitrogen cycling and biochar-mitigated remediation of microplastic-contaminated soil.

A Microbial Phenomics Approach to Determine Metabolic Signatures to Enhance Seabream Sparus aurata Traceability, Differentiating between Wild-Caught and Farmed

Background: The need for efficient and simplified techniques for seafood traceability is growing. This study proposes the Biolog EcoPlate assay as an innovative method for assessing wild and farmed Sparus aurata traceability, offering advantages over other molecular techniques in terms of technical simplicity. Methods: The Biolog EcoPlate assay, known for its high-throughput capabilities in microbial ecology, was utilized to evaluate the functional diversity of microbial communities from various organs of S. aurata (seabream) from the Mediterranean area. Samples were taken from the anterior and posterior gut, cloaca swabs and gills to distinguish between farmed and wild-caught individuals. The analysis focused on color development in OmniLog Units for specific carbon sources at 48 h. Results: Gills provided the most accurate clusterization of sample origin. The assay monitored the development of color for carbon sources such as α-cyclodextrin, D-cellobiose, glycogen, α-D-lactose, L-threonine and L-phenylalanine. A mock experiment using principal component analysis (PCA) successfully identified the origin of a blind sample. Shannon and Simpson indexes were used to statistically assess the diversity, reflecting the clusterization of different organ samples; Conclusions: The Biolog EcoPlate assay proves to be a quick, cost-effective method for discriminate S. aurata traceability (wild vs. farmed), demonstrating reliable reproducibility and effective differentiation between farmed and wild-caught seabream.

Biotechnological Potential of the Soil Microbiome

Molecular biological techniques and bioinformatic analysis were used to investigate the phylogenetic and functional diversity of the prokaryotic complex of soil microcosms. The dominant organisms of the hydrolytic community were different in the samples from different climatic zones. In the soils subject to anthropogenic or abiogenic load, apart from decreased diversity and abundance of prokaryotes, the number of the genes marking the ability to degrade xenobiotics, as well as those encoding nitrogen conversion and metabolism of vitamins and cofactors, was found to increase. Under heavy oil contamination, the bacterial community was capable of nitrification; its role increased in the lower horizons of the soil profile. The patterns revealed in the work indicate high metabolic potential of the prokaryotic component of the studied soils.

Crystal structure of the Rib domain of the cell-wall-anchored surface protein from Limosilactobacillus reuteri.

The immunoglobulin (Ig)-like domain is found in a broad range of proteins with diverse functional roles. While an essential β-sandwich fold is maintained, considerable structural variations exist and are critical for functional diversity. The Rib-domain family, primarily found as tandem-repeat modules in the surface proteins of Gram-positive bacteria, represents another significant structural variant of the Ig-like fold. However, limited structural and functional exploration of this family has been conducted, which significantly restricts the understanding of its evolution and significance within the Ig superclass. In this work, a high-resolution crystal structure of a Rib domain derived from the probiotic bacterium Limosilactobacillus reuteri is presented. This protein, while sharing significant structural similarity with homologous domains from other bacteria, exhibits a significantly increased thermal resistance. The potential structural features contributing to this stability are discussed. Moreover, the presence of two copper-binding sites, with one positioned on the interface, suggests potential functional roles that warrant further investigation.

Gut microbiota contributes to high-altitude hypoxia acclimatization of human populations.

The relationship between human gut microbiota and high-altitude hypoxia acclimatization remains highly controversial. This stems primarily from uncertainties regarding both the potential temporal changes in the microbiota under such conditions and the existence of any dominant or core bacteria that may assist in host acclimatization. To address these issues, and to control for variables commonly present in previous studies which significantly impact the results obtained, namely genetic background, ethnicity, lifestyle, and diet, we conducted a 108-day longitudinal study on the same cohort comprising 45 healthy Han adults who traveled from lowland Chongqing, 243 masl, to high-altitude plateau Lhasa, Xizang, 3658 masl, and back. Using shotgun metagenomic profiling, we study temporal changes in gut microbiota composition at different timepoints. The results show a significant reduction in the species and functional diversity of the gut microbiota, along with a marked increase in functional redundancy. These changes are primarily driven by the overgrowth of Blautia A, a genus that is also abundant in six independent Han cohorts with long-term duration in lower hypoxia environment in Shigatse, Xizang, at 4700 masl. Further animal experiments indicate that Blautia A-fed mice exhibit enhanced intestinal health and a better acclimatization phenotype to sustained hypoxic stress. Our study underscores the importance of Blautia A species in the gut microbiota's rapid response to high-altitude hypoxia and its potential role in maintaining intestinal health and aiding host adaptation to extreme environments, likely via anti-inflammation and intestinal barrier protection.

Quantifying the functional genes of C, N, P, and S cycling in a deep lake: Depth patterns and drivers

Microbial functional composition is important for biogeochemical cycles, and is usually constrained by taxonomic species pool and natural environmental gradients. However, the distribution of functional genes in deep lakes and the driving factors remains elusive. Here, we quantified the abundance of 71 functional genes relevant to carbon degradation, carbon fixation, methane metabolism, nitrogen cycling, phosphorus cycling, and sulfur cycling in 38 sediments along the water depth ranging from 0 to 90 m in Lugu Lake, China, using Quantitative Microbial Ecology Chip (QMEC) and then explored their water-depth diversity pattern and abiotic and biotic drivers. Functional gene diversity showed a hump-shaped pattern along the depth and peaked at around 50 m which is the low boundary of thermocline layer. There were specific environmental preferences among functional gene subgroups such as nitrogen and sulfur cycling genes preferring to deeper and shallow waters, respectively. The dissimilarity of total functional genes increased with water depth distance indicating a distance-decay relationship. There was a congruence between functional and taxonomic composition by showing the positive correlations between the compositions of functional genes and bacteria or archaea. This phenomenon is consistently observed for the six functional gene subgroups, and the congruence strength was highest for nitrogen cycling while lowest for sulfur cycling. Compared to abiotic factors, biotic factors were more relevant to the functional gene diversity and composition. Biotic factors explained 28.5 % of the variance of functional gene diversity, while water depth and other environmental factors such as water total phosphorus and sediment carbon explained 4.2 % and 3.8 %, respectively. For functional gene composition, biotic factors accounted for 25.2 % of the variance, whereas water depth and other environmental factors contributed to 0.7 % and 4.4 %, respectively. Among all explanatory variables for function genes, bacterial composition had the highest contribution, which was further supported by showing its direct effects of 1.45 and 0.86 on functional diversity and composition, respectively. This study for the first time quantified the microbial functional genes along water depth in deep lakes and provided a more comprehensive understanding of the functional dynamics in microbial communities within aquatic ecosystems.

Intercropping outweighs straw incorporation driving community and functional diversity of microarthropods after 5 years of tillage practices

Crop-leguminous intercropping and straw incorporation are considerable approaches to sustainable agriculture and have been widely used as a coping strategy to mitigate the negative effects caused by intensive agriculture. Yet, as a sustainable agriculture requires a deeper understanding of the impacts of conservation tillage practices on soil fauna, such as collembolans and acarid mites. These organisms are considered the most abundant and functionally critical soil fauna in many terrestrial natural, agricultural, and urban systems. In the present study, we assessed the responses of the community and functional diversity of collembolan and acarid mite assemblages to long-term intercropping and straw incorporation practices in a temperate farming land, in China. The experimental site was established with a full-factorial design of conservation managements (maize monocropping, maize-peanut intercropping, without maize straw addition, and with maize straw addition) over five consecutive years. Results showed that intercropping doubled collembolan and acarid density. Most of the enriched species in the intercropping field were euedaphic collembolans and cleptoparasitic mites. Nonetheless, the density of most phoretic species decreased, resulting in a negative effect of intercropping on acarid diversity. Despite straw incorporation additionally boosting the intercropping-induced increases in biomass, richness, and density of the collembolan community, the effects of straw incorporation on the community structure of collembolans and acarid mites were negligible. Similarly, intercropping affected the functional composition of collembolans and mites differently. Intercropping favored euedaphic collembolans characterized by less-developed furca, ocelli and sexual reproduction, but fungivorous, and benefited the cleptoparasitic mites that might be transported by their provisional hosts during pollinating peanut flowers. Moreover, intercropping decreased the functional dispersion of acarid mites, resulting in an acarid community with a homogenized ecological niche of acarid mites. In contrast, the ecological niche was more differentiated. Similar to intercropping, the ecological niche of collembolans in the field with straw was relatively higher, as well as the functional divergence, suggesting more intense resource competition between collembolans. In conclusion, intercropping has species-specific effects on the community and functional diversity of collembolans and mites and is relatively beneficial to collembolans, whereas straw incorporation has a marginal advantage on collembolans and acarid mites.

Unveiling multifaceted roles of myeloid innate immune cells in the pathogenesis of psoriasis

Psoriasis is a chronic inflammatory skin disease occurring worldwide. Initially viewed as a keratinocyte disorder, psoriasis is now recognized to involve a complex interplay between genetic predisposition, environmental triggers, and a dysregulated immune system, with a significant role of CD4+ T cells producing IL-17. Recent genetic studies have identified susceptibility loci that underscore the importance of innate immune responses, particularly the roles of myeloid cells, such as dendritic cells, macrophages, and neutrophils. These cells initiate and sustain inflammation through cytokine production triggered by external stimuli. They influence keratinocyte behavior and interact with adaptive immune cells. Recent techniques have further revealed the heterogeneity of myeloid cells in psoriatic lesions, highlighting the contributions of less-studied subsets, such as eosinophils and mast cells. This review examines the multifaceted roles of myeloid innate immune cells in psoriasis, emphasizing their functional diversity in promoting psoriatic inflammation. It also describes current treatment targeting myeloid innate immune cells and explores potential new therapeutic strategies based on the functional characteristics of these subsets. Future research should focus on the detailed characterization of myeloid subsets and their interactions to develop targeted treatments that address the complex immune landscape of psoriasis.

Determining diagnostic characteristics of the nonmarine Ostracoda (Crustacea) and their habitat selection with unique functional traits in the Kastamonu province (Türkiye)

Nonmarine ostracods are widely distributed in a variety of aquatic habitats, from mountain lakes to underground waters, where each species tends to show species-specific habitat preferences with unique functional traits to increase their survival chances. To understand the patterns of such a relationship between habitat preferences and functional traits of the species, 101 different aquatic sites in the Kastamonu province (Türkiye) were randomly sampled during August 2023. A total of 39 ostracods (20 species, 19 unnamed taxa) were encountered from 49 sites. Seventeen species are new reports for the province. Among them, six species are the most common species with cosmopolitan (or cosmoecious) characteristics. The contribution of these species to the diversity of alpha species (p < 0.05) was more than 90 %. The species with relatively high ecological tolerances generally unveiled low-optimum estimates. Canonical correspondence analysis explained 62.5 % of the correlation between environmental variables and species in which redox potential, electrical conductivity, calcium, and pH were found to be the most related variables to the species (p < 0.05). Fundiversity analysis showed that the presence of swimming setae was correlated with high values of functional diversity, functional richness, and functional distribution of species among five elevation ranges. The results of the habitat selection index and the standardized selection index coincided with the functional traits of the most common species. The species characterized by their habitat selection can be considered as diagnostic species of those specific habitats. Among them, Neglecandona neglecta, reported primarily from dams, springs, and troughs, is considered a typical diagnostic species of these habitats, while Cypridopsis vidua found in lakes and dams can be used as an indicator species for these types of lentic habitats. Similarly, three species (Heterocypris incongruens, Ilyocypris bradyi, Psychrodromus olivaceus) can play a critical role as diagnostic species in troughs but reporting them from different habitats such as ditches and rivers / lakes (I. bradyi) and dams (P. olivaceus and H. salina) indicated their wide range of habitat preferences. Hence, the results suggest that the occurrence of diagnostic species seems to correspond to certain habitat types and their functional traits.