Ecological Niche Research Articles

Environmental niche, spatial distribution and size structure of shelf-dwelling populations of the gorgonian Eunicella cavolini (Koch, 1887) in NW Mediterranean

Extensive knowledge exists about the ecology of gorgonian species dwelling in coastal areas of the Mediterranean, but less information is available regarding populations found in deep circalittoral and bathyal environments. In recent years, the use of marine imaging technology has led to the discovery of dense coral gardens below SCUBA depths. This is the case of Eunicella cavolini (Koch, 1887) populations dwelling on the continental shelf off Cap de Creus (northwestern Mediterranean), an area included in a Site of Community Importance (SCI) of the Natura 2000 Network. We characterized the environmental niche of this species using a combination of density data extracted from 60 underwater video transects (80–400 m depth) and a set of environmental factors of a geomorphologic, oceanographic and human nature. Populations of E. cavolini develop within a restricted combination of environmental conditions, predominantly in areas of the mid continental shelf (95–110 m depth) characterized by a mixture of substrates (gravels, pebbles and rocks) with intermediate yearly average bottom current velocities (0.11–0.13 m s−1) and where no records of bottom trawling activity were registered in the years prior to the surveys. The species forms dense aggregations that average 6–8 col·m−2, with local high-density peaks above 15 col·m−2. Areas suitable for the development of E. cavolini were modelled by means of a Random Forest algorithm, which predicted that an area extending over 14 ha could potentially host populations with densities over 5 col·m−2. Bottom current velocity emerged as the most important factor determining the spatial distribution of the species, followed by depth and presence of rocks. Colony height measurements indicated that populations are dominated by small-to-medium sized colonies, with average colony height positively correlated with gorgonian density. The reduced average colony height observed might respond to the strong bottom current regime characteristic of Cap de Creus, but also to the increased likelihood of larger colonies to be captured as by-catch by trammel nets, a common type of fishing gear used in the area. This study provides relevant information about the ecology of E. cavolini populations dwelling on deep circalittoral habitats, useful for policymakers when formulating specific management measures to foster the conservation of this species inside the SCI. Additionally, the data provided could assist on the restoration actions already taking place in Cap de Creus, and be used as baseline data to monitor the evolution of E. cavolini populations through time once management plans are implemented.

Overview of the Saccharomyces cerevisiae population structure through the lens of 3,034 genomes.

With the rise of high-throughput sequencing technologies, a holistic view of genetic variation within populations-through population genomics studies-appears feasible, although it remains an ongoing effort. Genetic variation arises from a diverse range of evolutionary forces, with mutation and recombination being key drivers in shaping genomes. Studying genetic variation within a population represents a crucial first step in understanding the relationship between genotype and phenotype and the evolutionary history of species. In this context, the budding yeast Saccharomyces cerevisiae has been at the forefront of population genomic studies. In addition, it has a complex history that involves adaptation to a wide range of wild and human-related ecological niches. Although to date more than 3,000 diverse isolates have been sequenced, there is currently a lack of a resource bringing together sequencing data and associated metadata for all sequenced isolates. To perform a comprehensive analysis of the population structure of S. cerevisiae, we collected genome sequencing data from 3,034 natural isolates and processed the data uniformly. We determined ploidy levels, identified single nucleotide polymorphisms (SNPs), small insertion-deletions (InDels), copy number variations (CNVs), and aneuploidies across the population, creating a publicly accessible resource for the yeast research community. Interestingly, we showed that this population captures ∼93% of the species diversity. Using neighbor-joining and Bayesian methods, we redefined the populations, revealing clustering patterns primarily based on ecological origin. This work represents a valuable resource for the community and efforts have been made to make it evolvable and integrable to future yeast population studies.

Using ensemble modeling to predict the current distribution of Pistacia atlantica Desf. in Algeria.

To understand the distribution of Atlas pistachio (Pistacia atlantica Desf.) in Algeria, we analyzed the environmental factors influencing its habitat. This study employs an ensemble modelling (EM) approach, a robust predictive technique in ecological niche modelling that enables us to identify critical environmental drivers affecting plant distributions across different ecosystems' focal species. The EM incorporated four prediction algorithms (generalized linear model, boosted regression trees, random forest, and maximum entropy algorithms); we modelled Atlas pistachio's niche with 2810 occurrence points and 32 environmental variables, including climatic, edaphic, topographic, and anthropogenic factors. The model demonstrated high accuracy, with an AUC of 0.97 and TSS of 0.88. Key factors influencing distribution were precipitation in the driest month (Bio14), soil bulk density (BD), cation exchange capacity (CEC), human modification, and average diurnal amplitude (Bio2), with a relative importance of 20.1%, 12.7%, 6.7%, 4.9%, and 3.1%, respectively. These findings underscore the utility of ensemble modelling to pinpoint specific environmental variables critical to the species' presence and ecological adaptability, which has broader implications for other plant species in arid landscapes. Notably, the probability of Atlas pistachio occurrence increased with BD and decreased with CEC and human influence. Our results emphasize the EM approach as a versatile tool in ecological modelling, facilitating species-specific analyses that contribute to broader ecological restoration efforts, especially in degraded arid and semi-arid regions. This study advances our understanding of Atlas pistachio's environmental requirements and highlights the importance of EM in developing targeted programs to restore degraded ecosystems.

Prevalence of Crimean-Congo Haemorrhagic Fever virus and Ganjam virus among livestock & ticks in Wayanad, Kerala.

The Western Ghat region of Kerala has abundant flora and domestic and wild animal species that provide an ideal ecological niche for the ticks. Kyasanur Forest Disease virus (KFDV), a zoonotic tick-borne virus causing Haemorrhagic fever, commonly known as monkey fever is prevalent in the area. The tick infestations have been documented in the majority of household animals in Wayanad and risks are further amplified as the majority of the animals reared, graze in the adjoining forest areas and these animals are often housed in and around farmer's dwellings. Therefore, the farmers are at high risk of contracting deadly tick-borne diseases, and surveillance in animals can act as an indicator of disease hotspots. Even though the tick-borne KFDV is endemic to the area, the surveillance data on other significant zoonotic tick-borne viruses such as CCHFV and GANV are scanty. Overall CCHFV seroprevalence of 2.33 was reported amongst livestock sampled. Species-wise percent seropositivity was 1.01 and 5.10 in cattle and goats, respectively. The study revealed the presence of ticks belonging to 3 genera viz. Rhipicephalus, Amblyomma, and Haemaphysalis. Despite the CCHFV seroprevalence, CCHFV and GANV could not be detected in ticks. Even though ticks were negative for the CCHFV genome, seroprevalence in adjoining taluks indicates the local virus circulation. Therefore serological as well as molecular investigation with a large number of samples collected at the peak of tick activity across the western ghat would help identify the potential hotspot for CCHFV.

Psyllid‐mite interactions promote psyllid fecundity by selecting for a different life history

AbstractBACKGROUNDIn interspecific competitive interactions at the same trophic level, herbivores are often hypothesized to exhibit a fast life‐history strategy characterized by early reproduction and a short lifespan. Here, we analyzed the shift in life history of the psyllid Bactericera gobica when it interacts with the aphid Aphis gossypii, the thrips Frankliniella occidentalis, or the mite Aceria pallida in similar ecological niches because all of them cause damage to goji berry leaves.RESULTSWe found that psyllids displayed a typical fast life history when interacting with aphids and thrips. Psyllids that interacted with mites also reproduced earlier than those without any interactions, but later than those interacting with aphids and thrips. Trophic competition typically led to a loss of fecundity in psyllids. To mitigate this loss, psyllids that interacted with mites allocated more resources to reproduction compared to those interacting with aphids and thrips, resulting in their reproduction being spread over a longer lifespan. This life history can be best described as a bet‐hedging strategy.CONCLUSIONOur study suggests that interspecific interactions cannot be solely explained by invoking faster life histories. Instead, the shift in life history may converge towards a finely‐tuned match between interacting species. Interactions between psyllids and mites increase psyllid fecundity, potentially promoting the persistence of both species. © 2024 Society of Chemical Industry.

A phenotypic study of the resistome in a peri-urban ecosystem

Since the discovery of antibiotics, the dispersion of resistance genes has increased exponentially, leading to the current state in which it has become increasingly difficult to achieve an effective treatment for infectious diseases. The enormous capacity for genetic exchange between microorganisms is causing resistance genes to be able to reach all environments, even those where there is no anthropogenic impact or exposure to these drugs. In this work, a phenotypic study of the resistome has been conducted in a peri-urban ecosystem (Granada, Spain), wherein the resistance to 32 antibiotics of 710 bacterial strains isolated from 70 samples from different ecological niches with varying levels of exposure to antibiotics and anthropic action has been determined. The study of resistances using phenotypic procedures constitutes a very useful and complementary alternative to genomic methods. The obtained results show a high percentage of resistance in all the subsystems analysed, stating high multi-resistance profiles. Vancomycin and erythromycin were the antibiotics to which the highest levels of resistance were observed, whereas the lowest levels were obtained in chloramphenicol. Regarding the environments studied, the highest percentages of resistance were found in wastewater, farms and food. It should be noted that in natural soil samples (not exposed to antibiotics or anthropogenic activities), worrying levels of resistance to practically all the groups of antibiotics analysed were detected. These results support the generally accepted conclusion that an appropriate control and management of wastewater and solid waste that may contain antibiotics or resistant bacteria is really important to prevent the wide propagation of the resistome in the environment.

The Effect of Climate Change on Spatio-Temporal Activity in Burrowing Frogs of the Smilisca Group

Measuring the potential effects of future climate changes on the spatio-temporal variance of optimal conditions for seasonal species is a key conservation issue. This study assesses the impact of climate change on the spatial and temporal patterns of optimal conditions for activity in two burrowing frogs, Smilisca fodiens and S. dentata. Ecological Niche Modeling was used to implement niche seasonality models, with calibration performed during the peak activity (July). These models were then transferred to current and future conditions for the remainder of the year, predicting future scenarios up to 2070 with an intermediate trajectory greenhouse gas concentration of 4.5 W/m2. Climate change transferability was assessed for four potential scenarios: 1) high precipitation and low temperature, 2) high precipitation and high temperature, 3) low precipitation and low temperature, and 4) low precipitation and high temperature. We examined the impact across future projected areas and analyzed geographic change trends based on latitude, longitude, and elevation. For both species, the best scenario would involve increased precipitation in the future. However, the worst-case would be a combination of reduced precipitation and higher temperatures. Due to large area loss, northern populations of S. fodiens may be highly vulnerable. Concerning S. dentata, the outlook is worrisome, with all known populations experiencing losses in most months. Area gains may not help either species since they tend to occur at elevations above their known ranges. Using a seasonal approach in spatio-temporal analysis enhances comprehension of the behavioral adaptations of seasonal species and their vulnerability to current and future climatic variations

Niche-Aware Metagenomic Screening for Enzyme Methioninase Illuminates Its Contribution to Metabolic Syntrophy

The single-step methioninase-mediated degradation of methionine (as a sulfur containing amino acid) is a reaction at the interface of carbon, nitrogen, sulfur, and methane metabolism in microbes. This enzyme also has therapeutic application due to its role in starving auxotrophic cancer cells. Applying our refined in silico screening pipeline on 33,469 publicly available genome assemblies and 1878 metagenome assembled genomes/single-cell amplified genomes from brackish waters of the Caspian Sea and the Fennoscandian Shield deep groundwater resulted in recovering 1845 methioninases. The majority of recovered methioninases belong to representatives of phyla Proteobacteria (50%), Firmicutes (29%), and Firmicutes_A (13%). Prevalence of methioninase among anaerobic microbes and in the anoxic deep groundwater together with the relevance of its products for energy conservation in anaerobic metabolism highlights such environments as desirable targets for screening novel methioninases and resolving its contribution to microbial metabolism and interactions. Among archaea, majority of detected methioninases are from representatives of Methanosarcina that are able to use methanethiol, the sulfur containing product from methionine degradation, as a precursor for methanogenesis. Branching just outside these archaeal methioninases in the phylogenetic tree, we recovered three methioninases belonging to representatives of Patescibacteria reconstructed from deep groundwater metagenomes. We hypothesize that methioninase in Patescibacteria could contribute to their syntrophic interactions where their methanogenic partners/hosts benefit from the produced 2-oxobutyrate and methanethiol. Our results underscore the significance of accounting for specific ecological niche in screening for enzyme variates with desired characteristics. Finally, complementing of our findings with experimental validation of methioninase activity confirms the potential of our in silico screening in clarifying the peculiar ecological role of methioninase in anoxic environments.

Exploring plant-microbe interactions in adapting to abiotic stress under climate change: a review.

Climatic change and extreme weather events have become a major threat to global agricultural productivity. Plants coexist with microorganisms, which play a significant role in influencing their growth and functional traits. The rhizosphere serves as an ecological niche encompassing plant roots and is a chemically complex environment that supports the growth and development of diverse plant-interactive microbes. Although plant-microbe interactions have been extensively investigated however, limited exploration have been made how abiotic stresses affect the structure and assembly of microbial communities in the rhizosphere. This review highlights climate change influence on plant growth, functional traits, and microbial communities. It explores plant mechanisms for mitigating abiotic stress, such as removing reactive oxygen species (ROS), regulating antioxidant activity and indole-3-acetic acid (IAA) production, and controlling growth-inhibitory ethylene levels through colonization by bacteria producing ACC deaminase. Additionally, we elaborated the systematic communicatory network steered by hormonal crosstalk and root exudation, which can modulate and initiate the dialogues between plants and surrounding microbes. This network ultimately promotes the chemotactic movement of microbes towards the rhizosphere, facilitating their early colonization. Finally, we reviewed the recent advancements for understanding how plant-microbe interactions foster resilience under climate stress.

Molecular Innovations Shaping Beak Morphology in Birds.

The beak, a pivotal evolutionary trait characterized by high morphological diversity and plasticity, has enabled birds to survive mass extinction events and subsequently radiate into diverse ecological niches worldwide. This remarkable ecological adaptability underscores the importance of uncovering the molecular mechanisms shaping avian beak morphology, particularly benefiting from the rapidly advancing archives of genomics and epigenomics. We review the latest advancements in understanding how genetic and epigenetic innovations control or regulate beak development and drive beak morphological adaptation and diversification over the past two decades. We conclude with several recommendations for future endeavors, expanding to more bird lineages, with a focus on beak shape and the lower beak, and conducting functional experiments. By directing research efforts toward these aspects and integrating advanced omics techniques, the complex molecular mechanisms involved in avian beak evolution and morphogenesis will be deeply interpreted.

Genetics of conditional extended mycelial cell viability of Streptomyces minutiscleroticus in deep starvation phase implicates the involvement of (p)ppGpp, clpX, and a histidine kinase sasA.

Bacterial lifespan ranges from a few hours to geological timescales. The prolonged survival trait under extreme energy starvation is essential for the perpetuation of their existence. The theme for long-term survival [long-term stationary phase (LTSP)] in the non-growing state may be dependent on the diversity in the environmental niche and the lifestyle of the bacteria, exemplified by longevity studies, albeit few, with model organisms. In the present study, we characterized the LTSP of mycelial cells of Streptomyces Minutiscleroticus, which remain metabolically active, demonstrate ongoing protein synthesis-killed by protein synthesis inhibitors-and remarkably by the cell-wall synthesis inhibitors, vancomycin, and ampicillin, suggesting "growth." Their rapid turnover is also evident in ~10-fold loss of colony-forming unit (CFU) over a year, suggesting that for the death of one "old" cell, slightly less than one "new" cell is born. This longevity is consequent to (i) induction of the gene expression program effected by non-metabolizable, non-ionic osmolyte, sucrose, thus conditional, and (ii) possibly rendering this carbon utilizable by the production of a slow hydrolytic activity generating glucose, reinforcing the relevance of low-level energy resource for long term survival in the starvation phase. The viability parameters of LTSP cells measured through up to 90 days suggest that the stationary phase transitioning into LTSP following nutrient exhaustion is nearly quantitative. Expectedly, the viability in LTSP is (p)ppGpp/RelA dependent. Whereas mutation in chaperone clpX, negatively affects survival in stationary phase, overexpression of signal sensor-transducer histidine kinase, SasA8, enhances cell survivability. The relevance of longevity functions identified here requires further deduction of the genetic program.

Complex interplay between the microfluidic and optical properties of Hoplia sp. beetles

BackgroundAll living organisms exist in a world affected by many external influences, especially water and light. Photonic nanostructures present in certain insects, have evolved over time in response to diverse environmental conditions, facilitating communication within and between species, camouflage, thermoregulation, hydration, and more. Up to now, only a few insect species have been discovered whose elytron changes its color due to permeation of water (or its vapor) through cuticle.ResultsHere we report on a scarabaeid beetle Hoplia argentea remarkable in its ability to shift from green to brownish-red when exposed to water, demonstrating reversible changes. Here we show that elytron and scales form a complex and efficient micro/nano-optofluidic system. Water is channeled into the elytral lacunae, then transported internally to the petals of the scales, where it is wicked inside each scale, pushing the entrapped air out. Wicking is a very fast process, occurring during a few seconds. The advantage of this principle is in extremely high pressure (approximately 15 bar) produced by capillary forces, which expediates permeation of air. We present optical models that explain the physical mechanisms behind the coloration, detailing how superhydrophilic properties influence optical behavior.ConclusionSpecies within the genus Hoplia exhibit diverse coloration strategies, likely linked to their specific ecological niches. These organisms have evolved intricate optical and microfluidic systems that facilitate rapid alterations in body coloration, potentially serving purposes such as environmental camouflage and thermoregulation. Studying microfluidic and optical properties of the elytra will not only enhance our understanding of the biological purposes behind color change but also inspires design of artificial biomimetic devices. Dynamic fluid flow patterns, described in this paper, are fairly constant and unique and can be used in security applications as a, so called, physically unclonable functions (PUF). More broadly, this kind of microfluidic system can be used for controlled drug release, sensing, hydraulic and pneumatic pumping.

Non-antibiotic disinfectant synchronously interferes methane production and antibiotic resistance genes propagation during sludge anaerobic digestion: Activation of microbial adaptation and reconfiguration of bacteria-archaea synergies

Waste activated sludge (WAS) presents both resource recovery potential and pollution risks, making its efficient treatment challenging. Anaerobic digestion is broadly recognized as a green and sustainable approach to WAS treatment, whose efficiency is easily impacted by the exogeneous pollutants in WAS. However, the impact of polyhexamethylene guanidine (PHMG), as a widely-used non-antibiotic disinfectant, on WAS digestion under semi-continuous flow conditions remains unclear. In this study, CH4 production decreased from 16.1 mL/g volatile suspended solids (VSS) in the control to 13.2 mL/g VSS and 0.3 mL/g VSS under low and high PHMG exposure, respectively, while PHMG increased the number of antibiotic resistance gene (ARG) copies per bacterium by 4.6-12.7 %. Molecular docking analysis revealed that PHMG could spontaneously bind to and disintegrate WAS (binding energy:2.35 and -9.62 kcal/mol), increasing the likelihood of microbial exposure to PHMG. This led to an increase in bacterial abundance and a reduction in archaeal populations, resulting in bacterial dominance in ecological niches. The network topology index in PHMG-treated reactors was consistently lower than in the control, with a higher proportion of negatively correlated links, indicating a more antagonistic relationship between bacteria and archaea. Consequently, PHMG significantly interfered with key genes involved in CH4 biosynthesis (e.g., mch and mtd). Interestingly, methanogenic activity and archaeal chemotaxis (e.g., rfk and cheA) partially recovered under low PHMG exposure due to archaeal adaptation through quorum sensing and two-component systems. However, this adaptation process also contributed to the propagation of ARGs through horizontal gene transfer, facilitated by the enhancement of mobile genetic elements and ARGs hosts. These findings confirm the ecological risks of PHMG and highlight the need for effective WAS disposal strategies.

The Role of Polyploidy in the Genetic Structure and Expansion of Lepisorus clathratus in the Qinghai-Tibetan Plateau and Hengduan Mountains.

Polyploidy plays a crucial role in plant evolution, particularly in shaping genetic diversity and geographic distribution. This study investigates the genetic diversity and distribution of Lepisorus clathratus (C. B. Clarke) Ching, a polyploid fern species endemic to the Qinghai-Tibetan Plateau and Hengduan Mountains. We sampled 586 individuals from 66 populations and identified three ploidy levels: diploid, tetraploid, and hexaploid. Flow cytometry and chloroplast DNA sequencing were used to assess ploidy variation and genetic structure. Tetraploid populations dominated the Hengduan Mountains and exhibited wider geographic ranges, while diploids were largely confined to the Qinghai-Tibetan Plateau. Molecular variance analysis revealed significant genetic differentiation among regions, with polyploid populations demonstrating higher cross-region migration rates compared with diploids, as evidenced by the historical gene flow analysis. Ecological niche modeling suggested that polyploids expanded more successfully in post-glacial periods, likely due to their greater ecological flexibility and capacity for long-distance colonization. These findings highlight the critical role of polyploidy in shaping genetic structure and species expansion, contributing to the understanding of plant adaptation in response to historical climatic changes.

Convergent Degenerated Regulatory Elements Associated with Limb Loss in Limbless Amphibians and Reptiles.

Limbs are a defining characteristic of tetrapods, yet numerous taxa, primarily among amphibians and reptiles, have independently lost limbs as an adaptation to new ecological niches. To elucidate the genetic factors contributing to this convergent limb loss, we present a 12 Gb chromosome-level assembly of the Banna caecilian (Ichthyophis bannanicus), a limbless amphibian. Our comparative analysis, which includes the reconstruction of amphibian karyotype evolution, reveals constrained gene length evolution in a subset of developmental genes across 3 large genomes. Investigation of limb development genes uncovered the loss of Grem1 in caecilians and Tulp3 in snakes. Interestingly, caecilians and snakes share a significantly larger number of convergent degenerated conserved noncoding elements than limbless lizards, which have a shorter evolutionary history of limb loss. These convergent degenerated conserved noncoding elements overlap significantly with active genomic regions during mouse limb development and are conserved in limbed species, suggesting their essential role in limb patterning in the tetrapod common ancestor. While most convergent degenerated conserved noncoding elements emerged in the jawed vertebrate ancestor, coinciding with the origin of paired appendage, more recent degenerated conserved noncoding elements also contribute to limb development, as demonstrated through functional experiments. Our study provides novel insights into the regulatory elements associated with limb development and loss, offering an evolutionary perspective on the genetic basis of morphological specialization.

Randomising spatial patterns supports the integration of intraspecific variation in ecological niche models

Ecological niche models (ENMs) are an essential modelling technique in biodiversity prediction and conservation and are frequently used to forecast species responses to global changes. Classic species‐level models may show limitations as they assume species homogeneity, neglecting intraspecific variation. Composite ENMs allow the integration of intraspecific variation by combining intraspecific‐level ENMs, capturing individual environmental responses over the species' geographic range. While recent studies suggest that accounting for intraspecific variation improves model predictions, we currently lack methods to test the significance of the improvement. Here, we propose a null model approach that randomises observed intraspecific structures as an appropriate baseline for comparison. We illustrate this approach by comparing predictive performance of a species‐level ENM to composite ENMs for European beech Fagus sylvatica. To investigate the influence of spatial lineage structure, we tested all models against the same withheld data to allow comparison across models based on five common performance metrics. We found that the species‐level ENM expressed higher overall performance (i.e. AUC, TSS, and Boyce index) and specificity (ability to predict absences), while the composite ENMs achieved higher sensitivity (ability to predict presences). In line with this, the composite ENMs also showed increased sensitivity and decreased specificity compared to the null models that randomised lineage structure. We showed that the assessment of model performance strongly varies based on the used measures, emphasising a careful investigation of multiple measures for evaluation. The application of null models allowed us to disentangle the effect of observed patterns of intraspecific variation in ENMs. Further, we highlight the validation and use of well‐founded subgroups for modelling. Although intraspecific variation improves the prediction of occurrences of European beech, it did not fully outcompete the classic species‐level model and should be used with care and rather to improve understanding and to supplement, not replace, species‐level models.

Avian Responses to Different Grazing Management Practices in Neotropical Temperate Grasslands: A Meta-Analysis

Bird populations inhabiting the Rio de la Plata Grasslands in southern Brazil, Argentina, and Uruguay are known to be affected by livestock grazing practices. Cattle grazing can lead to changes in bird assemblages by affecting the heterogeneity of vegetation structures. We conducted a meta-analysis using studies that reported bird richness and abundance under different grazing management practices. We compared ranches under continuous grazing management (control, CGM) to (1) ranches under technological inputs management (TIM, herbicides and exotic pastures) and (2) ranches under ecological process-based management (EPM), which include ranches that utilise controlled and rotational grazing. We used random effects multilevel linear models to evaluate grazing regimen impacts. Our results indicate a negative impact of TIM on both bird abundance and richness (mean ± SE: −0.25 ± 0.07 and −0.92 ± 0.10, respectively) since the use of inputs simplifies vegetation structure and results in the loss of ecological niches. Compared to CGM, the influence of EPM on total bird abundance appears to be more dependent on grassland height, as evidenced by a decline in short grasses and increase in tall grasses. Our meta-analysis suggests that EPM practices may be beneficial for the conservation of endangered tall-grass birds.

Distinct causes underlie double-peaked trilobite morphological disparity in cephalic shape

Trilobite cephalic shape disparity varied through geological time and was integral to their ecological niche diversity, and so is widely used for taxonomic assignments. To fully appreciate trilobite cephalic evolution, we must understand how this disparity varies and the factors responsible. We explore trilobite cephalic disparity using a dataset of 983 cephalon outlines of c. 520 species, analysing the associations between cephalic morphometry and taxonomic assignment and geological Period. Elliptical Fourier transformation visualised as a Principal Components Analysis suggests significant differences in morphospace occupation and in disparity measures between the groups. Cephalic shape disparity peaks in the Ordovician and Devonian. The Cambrian–Ordovician expansion of morphospace occupation reflects radiations to new niches, with all trilobite orders established by the late Ordovician. In comparison, the Silurian–Devonian expansion seems solely a result of within-niche diversification. Linear Discriminant Analyses cross-validation, average cephalon shapes, and centroid distances demonstrate that, except for Harpida and the Cambrian and Ordovician Periods, order and geological Period cannot be robustly predicted for an unknown trilobite. Further, k-means clustering analyses suggest the total dataset naturally subdivides into only seven groups that do not correspond with taxonomy, though k-means clusters do decrease in number through the Palaeozoic, aligning with findings of decreasing disparity.

Enhancing monitoring to promote early detection and eradication of invasive species

Ecological niche models are often used to predict the distribution of invasive species before or after they have been detected in new regions. Such models should also be used to guide surveys to promote the early detection and eradication of invasive species. Here we propose a practical framework that seamlessly uses ecological niche models to develop sampling routes that promote detection of invasive species. Our framework uses habitat suitability predictions and occurrence data on incursion populations to generate potential survey sites, which are then prioritized for sampling based on their size and suitability. The generated survey route is then displayed on an open street map platform. Our framework was developed into the ‘enmRoute' R package and a user‐friendly website to facilitate its application, and we validated our framework with a case study. We show that integrating ecological niche models with human transport routes promotes identification of survey sites that are predicted to collect more individuals and have a greater potential for species detection than traditional sampling approaches. Our framework may help industries, invasion biologists, and regulators develop economical and efficient survey programs for invasive pest monitoring that make eradication programs more attainable.

An integrative approach to the taxonomy of Oxymycterus paramensis (Rodentia, Cricetidae) and related nominal forms

Abstract Oxymycterus includes 17 species of small- to medium-sized sigmodontine rodents. The taxonomy of this genus has been widely studied, but several unresolved issues persist. One example of this is the Paramo Hocicudo, Oxymycterus paramensis, which over its extended latitudinal range has been associated with several nominal forms that have not been evaluated with an integrative approach. Based on phylogenetic analyses of the Cytb gene, qualitative and quantitative morphological characters, and environmental niche modeling, we reexamined the taxonomic status of the nominal forms akodontius, jacentior, and paramensis while considering the recently recognized species O. willkaurco. The phylogenetic reconstruction guided subsequent analysis of morphological variation and the development of the niche models. Considering the results in an integrative framework, we observed congruence among phylogenetic, species distribution models, and environmental niche models (a proxy indicating different environmental preferences), which support the recognition of 2 species within the concept of O. paramensis s.l. At the same time, we did not observe congruent support for this taxonomic hypothesis from morphological evidence, with the absence of diagnostic qualitative or quantitative characters differentiating the 2 taxa. Considering that some lines of evidence suggest the interruption of gene flow, we see more support for recognizing existing names for 2 taxa at the species level: O. paramensis, endemic to Bolivia; and O. akodontius (which has priority over jacentior), distributed from southern Bolivia to northwestern Argentina. However, we recommend more detailed studies to test the taxonomic scenario advanced here.