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Crocosphaera watsonii is a unicellular N2‐fixing (diazotrophic) cyanobacterium observed in tropical and subtropical oligotrophic oceans. As a diazotroph, it can be a source of bioavailable nitrogen (N) to the microbial community in N‐limited environments, and this may fuel primary production in the regions where it occurs. Crocosphaera watsonii has been the subject of intense study, both in culture and in field populations. Here, we summarize the current understanding of the phylogenetic and physiological diversity of C. watsonii, its distribution, and its ecological niche. Analysis of the relationships among the individual Crocosphaera species and related free‐living and symbiotic lineages of diazotrophs based on the nifH gene have shown that the C. watsonii group holds a basal position and that its sequence is more similar to Rippkaea and Zehria than to other Crocosphaera species. This finding warrants further scrutiny to determine if the placement is related to a horizontal gene transfer event. Here, the nifH UCYN‐B gene copy number from a recent synthesis effort was used as a proxy for relative C. watsonii abundance to examine patterns of C. watsonii distribution as a function of environmental factors, like iron and phosphorus concentration, and complimented with a synthesis of C. watsonii physiology. Furthermore, we have summarized the current knowledge of C. watsonii with regards to N2 fixation, photosynthesis, and quantitative modeling of physiology. Because N availability can limit primary production, C. watsonii is widely recognized for its importance to carbon and N cycling in ocean ecosystems, and we conclude this review by highlighting important topics for further research on this important species. [ABSTRACT FROM AUTHOR]

Ecological processes that are behind distributions of species that inhabit isolated localities, complex disjunct distributions, remain poorly understood. Traditionally, vicariance and dispersion have been proposed as explanatory mechanisms that drive such distributions. However, to date, our understanding of the ecological processes driving evolution of ecological niches associated with disjunct distributions remains rudimentary.Here, we propose a framework to deconstruct drivers of such distribution using World's most widespread freshwater fish Galaxias maculatus as a model and integrating marine and freshwater environments where its life cycle may occur. Specifically, we assessed ecological and historical factors (Gondwanan vicariance, marine dispersion) and potential dispersion (niche‐tracking) that explain its distribution in the Southern Hemisphere.Estimated distribution was consistent with previously reported distribution and mainly driven by temperature and topography in freshwater environments and by primary productivity and nitrate in marine environments. Niche dynamics of G. maculatus provided evidence of synergy between vicariance and marine dispersion as explanatory mechanisms of its disjunct distribution, suggesting that its ecological niche was conserved since approximately 30 Ma ago.This integrated assessment of ecological niche in marine and freshwater environments serves as a generic framework that may be applied to understand processes underpinning complex distributions of diadromous species. [ABSTRACT FROM AUTHOR]

Ecological similarity plays an important role in biotic interactions. Increased body size similarity of competing species, for example, increases the strength of their biotic interactions. Body sizes of many exothermic species are forecast to be altered under global warming, mediating shifts in existing trophic interactions among species, in particular for species with different thermal niches.Temperate rocky reefs along the southeast coast of Australia are located in a climate warming hotspot and now house a mixture of temperate native fish species and poleward range‐extending tropical fishes (vagrants), creating novel species assemblages. Here, we studied the relationship between body size similarity and trophic overlap between individual temperate native and tropical vagrant fishes.Dietary niche overlap between vagrant and native fish species increased as their body sizes converged, based on both stomach content composition (short‐term diet), stable isotope analyses (integrated long‐term diet) and similarity in consumed prey sizes.We conclude that the warming‐induced faster growth rates of tropical range‐extending fish species at their cool water ranges will continue to converge their body size towards and strengthen their degree of trophic interactions and dietary overlap with co‐occurring native temperate species under increasing ocean warming. The strengthening of these novel competitive interactions is likely to drive changes to temperate food web structures and reshuffle existing species community structures. [ABSTRACT FROM AUTHOR]

First-order streams serve as a nursery of macroinvertebrates which act as secondary producers in the aquatic food chain and indicators of water quality. The present investigation conducted on three first-order streams of Badiyar Gad revealed Trichoptera to be the most diverse order followed by Ephemeroptera, Diptera, Coleoptera, Odonata, Lepidoptera, Plecoptera, Hemiptera, Arhynchobdellida, and Decapoda, indicating good water quality for these streams. High density, diversity, and even distribution of benthic macroinvertebrates during the winter season indicated stable ecosystems and healthy water quality. The presence of 35 families and 52 genera indicates a good habitat with numerous ecological niches for the macroinvertebrates. Two genera Maruina and Neophylax were identified as unique in these streams. They have not been previously reported from the Garhwal Himalayan streams. [ABSTRACT FROM AUTHOR]

Trait polymorphisms can vary across different contexts of selection and be maintained through trade-offs between these contexts. For example, colour polymorphic variants may represent alternative strategies optimizing crypsis or thermoregulation in different populations. Here we use visual modelling to test the conspicuousness of different colour pattern morphs in males and females of an Australian lizard, Lampropholis delicata , to predators and conspecifics. We further assess differences in reflectance, microhabitat selection, and mate preference to determine the functional role of the polymorphism and explain its variable distribution across latitude and the sexes. Plain morphs are more conspicuous than striped morphs in both bird and lizard visual models, suggesting predation selection, and habitat structure varies among sex-morph types, but we find no difference in microhabitat selection or mate preference based on colour. We suggest that a combination of spatially varying selection, habitat preference, and context-specific behaviour may be necessary to explain spatial patterns of colour morph frequencies. [ABSTRACT FROM AUTHOR]

The regulation of energy, water and thermal balance involves integrated processes that should drive ecological responses of ectotherms to climate change. Functional tradeoffs between thermoregulation and hydroregulation are exacerbated during hot or dry spells, but how microhabitat hydric properties and trophic resource availability influence these tradeoffs remains unknown. Here, we investigated the effects of microhabitat humidity and food availability on thermo‐hydroregulation strategies in the ground‐dwelling common lizard Zootoca vivipara during a simulated hot and dry spell event. We exposed lizards to a five‐day long acute water restriction in hot conditions in the laboratory and manipulated hydric quality of the retreat site (wet or dry shelter) as well as food availability (ad libitum food or food deprivation). Water restriction and food deprivation caused physiological responses such as muscle catabolism and mobilization of caudal energy reserves. Lizards also developed behavioural strategies to conserve water or energy via decreased thermoregulation effort, higher shelter use and increased eye closure behaviours through time. These physiological and behavioural changes were importantly buffered by the presence of a wet shelter but not by food availability. A wet retreat site reduced the behavioural conflicts between thermoregulation and hydroregulation, allowed lizards to maintain a better condition and reduced physiological dehydration. Instead, food intake did not play a major role in the regulation of hydration state and increased behavioural conflicts between thermoregulation and hydroregulation. A better consideration of thermo‐hydroregulation behaviours and microhabitat hydric quality is required to address ectotherm responses to future climate change. [ABSTRACT FROM AUTHOR]

Synchronous variation in demographic parameters across species increases the risk of simultaneous local extinction, which lowers the probability of subsequent recolonization. Synchrony therefore tends to destabilize meta‐populations and meta‐communities. Quantifying interspecific synchrony in demographic parameters, like abundance, survival, or reproduction, is thus a way to indirectly assess the stability of meta‐populations and meta‐communities. Moreover, it is particularly informative to identify environmental drivers of interspecific synchrony because those drivers are important across species. Using a Bayesian hierarchical multisite multispecies mark–recapture model, we investigated temporal interspecific synchrony in annual adult apparent survival for 16 common songbird species across France for the period 2001–2016. Annual adult survival was largely synchronous among species (73%, 95% credible interval [47%–94%] of the variation among years was common to all species), despite species differing in ecological niche and life history. This result was robust to different model formulations, uneven species sample sizes, and removing the long‐term trend in survival. Synchrony was also shared across migratory strategies, which suggests that environmental forcing during the 4‐month temperate breeding season has a large‐scale, interspecific impact on songbird survival. However, the strong interspecific synchrony was not easily explained by a set of candidate weather variables we defined a priori. Spring weather variables explained only 1.4% [0.01%–5.5%] of synchrony, while the contribution of large‐scale winter weather indices may have been stronger but uncertain, accounting for 12% [0.3%–37%] of synchrony. Future research could jointly model interspecific variation and covariation in breeding success, age‐dependent survival, and age‐dependent dispersal to understand when interspecific synchrony in abundance emerges and destabilizes meta‐communities. [ABSTRACT FROM AUTHOR]

The present study utilized an ensemble modelling approach to predict the distribution of Diospyros melanoxylon under present, past (last glacial maximum (LGM), ~ 22 000 years BP, middle Holocene (MH) ~ 6000 years BP) and future climate change scenarios (RCP 2.6 and 8.5 for 2050s and 2070s). The annual mean temperature, mean temperature of the wettest quarter and annual precipitations were the most critical parameters that chiefly influence the distribution of D. melanoxylon. The ensemble model rendered high accuracy with AUC = 0.93, TSS = 0.74 and Kappa = 0.71. Past projections of D. melanoxylon indicated a widespread distribution during LGM and MH suggesting its adaptability to semi‐dry as well as warm and humid climate, respectively. Presence of fossil pollen evidence of D. melanoxylon in the suitable habitats derived through past projections in this study complements the model results and marks occurrences of the species during LGM and MH. By 2050s and 2070s (RCP 8.5), there would be a decline in the distribution by only 0.4% (13 622 km2) and 0.2% (6842 km2) of the extremely suitable habitats, respectively. The main factor leading to reduced habitat suitability is the anticipated rise in temperature and variations in seasonal precipitation patterns. Our findings, help in identifying the parts of the country which would be severely affected by future climate change scenarios and plan conservation strategies for this commercially important species to facilitate its growth in suitable habitats which are likely to sustain under future climatic conditions. [ABSTRACT FROM AUTHOR]

Ecological value (EV) is a term used to characterize the biotic or abiotic elements of a landscape, excluding human influence. Significant criteria for EV estimation can be grouped into two categories: ecological properties (biodiversity and vulnerability) and functional/structural features (fragmentation, connectivity, and resilience). While various methodological frameworks exist for estimating these criteria, few studies integrate all five criteria, and even fewer compare their results with fieldwork data. The objective of this study was to devise a novel spatial modelling tool for EV estimation based on biodiversity, vulnerability, fragmentation, connectivity, and resilience, utilizing data from Neotropical montane forests in west-central Mexico. The model incorporated data on (i) biodiversity and vulnerability estimated through ecological niche models, (ii) fragmentation and connectivity using landscape spatial patterns, and (iii) resilience estimated through the inverse of the vegetation sensitivity index. The results were then compared with fieldwork data. Natural protected areas within the Neotropical montane forests of west-central Mexico exhibited high EVs; however, a substantial portion of these forests lack legal protection. In terms of vegetation types, cloud and semideciduous forests exhibited the highest EV, emphasizing the urgent need for legal protection of these vital ecosystems. The comparison process demonstrated a moderate to high correlation in some criteria between the spatial and fieldwork data, indicating that the spatial model robustly captured the landscape spatial patterns. The spatial modelling tool proposed in this study is not only practical but also reproducible and applicable globally. Its efficacy lies in combining ecological properties with the functional and structural features of the landscape, making it particularly suitable for delineating protected natural areas and contributing to landscape planning efforts. [ABSTRACT FROM AUTHOR]

Hybridisation can be an important driver of evolutionary change, but hybridisation with invasive species can have adverse effects on native biodiversity. While hybridisation has been documented across taxa, there is limited understanding of ecological factors promoting patterns of hybridisation and the spatial distribution of hybrid individuals. We combined the results of ecological niche modelling (ENM) and restriction site‐associated DNA sequencing to test theories of niche conservatism and biotic resistance on the success of invasion, admixture, and extent of introgression between native and non‐native fishes. We related Maxent predictions of habitat suitability based on the native ranges of invasive Eastern Banded Killifish (Fundulus diaphanus diaphanus Lesueur 1817) and native Western Banded Killifish (Fundulus diaphanus menona Jordan and Copeland 1877) to admixture indices of individual Banded Killifish. We found that Eastern Banded Killifish predominated at sites predicted as suitable from their ENM, consistent with niche conservatism. Admixed individuals were more common as Eastern Banded Killifish habitat suitability declined. We also found that Eastern Banded Killifish were most common at sites closest to the presumed source of this invasion, whereas the proportion of admixed individuals increased with distance from the source of invasion. Lastly, we found little evidence that habitat suitability for Western Banded Killifish provides biotic resistance from either displacement by, or admixture with, invasive Eastern Banded Killifish. Our study demonstrates that ENMs can inform conservation‐relevant outcomes between native and invasive taxa while emphasising the importance of protecting isolated Western Banded Killifish populations from invasive conspecifics. [ABSTRACT FROM AUTHOR]

Since widespread monitoring began in 1976 in the UK, habitat‐specialist butterfly populations have declined dramatically. The main driver is habitat degradation, caused primarily by land‐use change, perhaps interacting with changes in vegetation phenology.Here, we focus on two declining species: Boloria selene (Dennis & Schiffermüller) and Boloria euphrosyne L., Lepidoptera: Nymphalidae. We hypothesise that these species differ in their preferred breeding habitat, and this is driven by differences in their temperature preferences, mediated by vegetation cover.We use mark‐release‐recapture techniques and oviposition observations to characterise and compare adult distribution, habitat use and oviposition site preferences of the two species.Egg‐laying females of both species are shown to occur in areas with relatively high abundance of the larval food plants, Viola spp. (violets), principally V. riviniana, and they oviposit where Viola spp. abundance is locally high. However, in contrast to B. selene, ovipositing B. euphrosyne tends to occur in areas with relatively short and sparse cover of vegetation.B. euphrosyne oviposit in sites with a relatively high plant surface temperature irrespective of ambient temperatures, in contrast with B. selene in which the temperature of oviposition sites increases as ambient temperature increases. These differential temperature strategies likely underlie differences in breeding habitat preference.Microclimatic cooling caused by increased vegetation growth in spring may be one reason B. euphrosyne is declining in the UK, while both B. euphrosyne and B. selene may be affected by declining Viola spp. availability. Our data provide further evidence that drivers of butterfly declines can be multi‐factorial, and paradoxically, that thermophilic species do not necessarily benefit from climate warming if responses of other species result in cooling of their habitats. [ABSTRACT FROM AUTHOR]

Background: Ecological and genomic attributes of populations can provide two orthologous perspectives on the biological profiles associated with local adaptation. The ability of organisms to track suitable habitats (ecological adaptability) and of populations to shift allele frequencies (adaptive potential) are prerequisite for population sustainability. Aims: Many contemporary populations are threatened by habitat loss (ecological vulnerability) and a lack of adaptive potential (evolutionary vulnerability). Technical advances provide new opportunities to address these challenges in biological conservation: Future habitat shifts can be predicted by ecological niche modelling and adaptive genetic diversity can be discerned using genome sequence data. Together, these two approaches illuminate the local adaptation profile and help identify the environmental and genomic conditions that should maximize evolutionary fitness. Materials and Methods: Here, we reviewed the primary literature to identify key studies that utilize both whole‐genome resequencing (WGR) and ecological niche modelling (ENM) in an effort to envisage future research directions that may benefit conservation efforts. Results: We identified ways to integrate different approaches, such as ENM‐informed adaptive genomics and adaptive genomics‐informed ENMs, that can be used to delineate and conserve local adaptation profiles. Discussion: Integrative approaches can identify adaptive characteristics, vulnerable populations subject to environmental changes, and the patterns of local adaptation from geographic and genomic analyses. We discuss future research directions, limitations and their potential solutions with suggestions for collaborative workflows. Conclusion: The integration of WGR and ENM is promising with their continuous advancement. An integrative approach can be used to evaluate eco‐evolutionary attributes, at both organismal and molecular levels, that can be used to help conserve local adaptation profiles. [ABSTRACT FROM AUTHOR]

Aim: Global climate change has been linked to shifts in species' geographic and elevational distributions, with taxa varying in responsiveness. This variation may be due to a time lag in response or climate alone not being a simple determinant of distribution limits. To tease apart the role of climate in distribution, we compared the temperature response of predicted occurrence revealed by ecological niche modelling (ENM) on historical climate with that of performance in a multi‐population transplant experiment. Congruence would support that climate is a main driver of distribution limits of a species. Location: North America. Taxon: Arabidopsis lyrata subsp. lyrata. Methods: Seeds of 20 populations of North American Arabidopsis lyrata from across the entire range were collected, propagated and then sown along a latitudinal transect across and beyond the species' range. Lifetime performance was related to the main niche‐ and range‐determining climatic variable revealed by ENM. Results: Lifetime performance did not consistently decline towards the high‐latitude range limit, but it did so towards the low‐latitude range limit. This decline was slightly weaker for low‐latitude populations, indicating divergent climate adaptation. The overall performance curve on the field‐measured minimum temperature in early spring was fairly congruent with the curve of ENM‐predicted suitability on this important niche‐determining variable. ENM‐based projections revealed that the southernmost populations were vulnerable under climate warming. Main Conclusions: Results verified that ENM based on species occurrences can well‐predict plant performance under field conditions. Congruence teaches us that with the climate change so far, the species exhibits a colonisation deficit in the north. Furthermore, the southernmost populations are vulnerable to extinction. A likely outcome is the shrinking of the species' range. [ABSTRACT FROM AUTHOR]

Since being described in the year 2000, little ecological information has accumulated for South Mountains Gray-Cheeked Salamanders (Plethodon meridianus), a narrowly distributed salamander in southern Appalachia. In this study, we used repeat surveys to model occupancy and abundance of P. meridianus along a transect running from the approximate range center to range edge. We found a strong effect of elevation and distance to streams as predictors of occupancy and abundance. The number of days since rain had a strong impact on detection probability, likely due to its effect on salamander surface activity (i.e., time outside of burrow), as opposed to observer error. Treating elevation as a proxy for distance to the range edge, we found that occupancy and abundance declined toward the range edge, supporting the center-periphery hypothesis. Our findings matched that of similar previous studies: at low elevations in dry habitat, salamanders are only found along the cooler microhabitat of streams, whereas at high elevations, salamanders are more widespread across the landscape. [ABSTRACT FROM AUTHOR]

Sympatric animals may consume diets of differing breadths as a strategy to reduce competition. Studying patterns of dietary breadth in extinct taxa is difficult because available data are generally limited to morphology. Dental topographic analysis (DTA) is useful for comparing occlusal morphology and allows for examination of dietary adaptations in extinct taxa. What remains unknown is how dental morphology, quantified using DTA, covaries with dietary breadth. The niche variation hypothesis (NVH) posits that taxa with broader ecological niches will be characterized by greater variability in morphology relative to specialized taxa. Therefore, we predict that taxa with greater dietary breadth will have more varied dental morphology compared to specialists as a result of the molar morphology of specialists being under greater genetic control relative to generalists, with specialists requiring teeth specially adapted to efficiently process a smaller range of food sources. We measured curvature, complexity, and relief of the M2 of 3 pairs of closely related euarchontan mammals (primates and treeshrews), with each taxon within a pair categorized as a generalist or specialist. Our results indicate that generalists do not consistently show greater variability in dental morphology compared to specialists among primates, but that atelids and treeshrews do generally follow the predictions of the NVH, with the caveat that our treeshrew sample is small. This suggests that while dietary specialists may be under greater genetic constraint with respect to their molar topography, a link between dietary breadth and dental form is not clear. Our study demonstrates that variation in dental topography does not necessarily reflect dietary breadth and highlights the fact that it is difficult to categorize even the most specialized primates (i.e. bamboo lemurs) as "dietary specialists." [ABSTRACT FROM AUTHOR]

Background: This study explores the biosynthesis, characteristics, and functional properties of exopolysaccharide produced by the strain Liquorilactobacillus mali T6-52. The strain demonstrated significant EPS production with a non-ropy phenotype. Results: The genomic analysis unveiled genes associated with EPS biosynthesis, shedding light on the mechanism behind EPS production. These genes suggest a robust EPS production mechanism, providing insights into the strain's adaptability and ecological niche. Chemical composition analysis identified the EPS as a homopolysaccharide primarily composed of glucose, confirming its dextran nature. Furthermore, it demonstrated notable functional properties, including antioxidant activity, fat absorption capacity, and emulsifying activity. Moreover, the EPS displayed promising cryoprotective activities, showing notable performance comparable to standard cryoprotective agents. The EPS concentration also demonstrated significant freeze-drying protective effects, presenting it as a potential alternative cryoprotectant for bacterial storage. Conclusions: The functional properties of L. mali T6-52 EPS reveal promising opportunities across various industrial domains. The strain's safety profile, antioxidant prowess, and exceptional cryoprotective and freeze-drying characteristics position it as an asset in food processing and pharmaceuticals. [ABSTRACT FROM AUTHOR]

In this paper, we use a stochastic partial differential equation (SPDE) as a model for the density of a population under the influence of random external forces/stimuli given by the environment. We study statistical properties for two crucial parameters of the SPDE that describe the dynamic of the system. To do that, we use the Galerkin projection to transform the problem, passing from the SPDE to a system of independent SDEs; in this manner, we are able to find the maximum likelihood estimator of the parameters. We validate the method by using simulations of the SDEs. We prove consistency and asymptotic normality of the estimators; the latter is showed using the Malliavin–Stein method. We illustrate our results with numerical experiments. [ABSTRACT FROM AUTHOR]

Digestive system tumors are the leading cause of cancer-related deaths worldwide. Despite ongoing research, our understanding of their mechanisms and treatment remain inadequate. One promising tool for clinical applications is the use of gastrointestinal tract tumor organoids, which serve as an important in vitro model. Tumor organoids exhibit a genotype similar to the patient's tumor and effectively mimic various biological processes, including tissue renewal, stem cell, and ecological niche functions, and tissue response to drugs, mutations, or injury. As such, they are valuable for drug screening, developing novel drugs, assessing patient outcomes, and supporting immunotherapy. In addition, innovative materials and techniques can be used to optimize tumor organoid culture systems. Several applications of digestive system tumor organoids have been described and have shown promising results in related aspects. In this review, we discuss the current progress, limitations, and prospects of this model for digestive system tumors. [ABSTRACT FROM AUTHOR]

0D biomaterials (0DBMs) can serve as carriers to enhance and extend the regulatory effects of biological cues they transport on cell fate via bacterial/mammalian cell internalization. However, accurately delivering and amplifying biosignals through 0DBMs remains challenging to cope with ecological niche destabilization induced by factors such as trauma or infection. Herein, the "zero‐dimensional amplification" approach is employed to develop a surface carboxylate carbon dot (CQD‐COOH) conjugated with a neutrophil constitutive peptide (LL‐37), resulting in the formation of a 0D peptide quantum dot (LQD). Hydrogel‐released LQDs, when internalized by bacteria, cause the bacteria to programmatically rupture and die, whereas LQDs internalized by mesenchymal stem cells (MSCs) activate the cellular CXCL12/CXCR4 signaling axis, which directs the stem cells to homing and anchor to the surface of the hydrogel coating. Notably, this strategy of "zero‐dimensional amplification" enables the antimicrobial performance of LL‐37 to be boosted approximately 1.3‐fold, significantly extending the transmission efficiency of biosignals. Meanwhile, 0D lipid nanoparticles (lipo‐NPs) with targeting function incorporated into the hydrogel could deliver the bio‐small molecule MK‐4 to MCSs and induce their endocytosis, further enhancing osseointegration. Thus, the hydrogel coating (HGLL) under this strategy can significantly remodel the ecological niche of the implant–bone interface in infected environment. [ABSTRACT FROM AUTHOR]

Understanding spatial ecology and predicting animal movements in response to environmental changes, such as anthropogenic climate change and multidecadal variability, is critical for effective conservation strategies. Niche structuring is key to some coastal shark species and size classes coexisting in the US Atlantic and Gulf of Mexico to limit interspecific and intraspecific interaction. Data from four fishery‐independent bottom longline surveys were used to evaluate the abiotic ecological niches of eight species of small and large coastal sharks. Gaussian mixture models separated length composition data into 14 size categories for ecological niche analysis. Generalized additive mixed effect models were fit and coupled with output from dynamic high‐resolution ocean models to predict suitable abiotic habitats, evaluate potential shifts in distribution, and explore the impacts of large‐scale climatological trends on abiotic habitats from 1994 to 2019. The abiotic niche for small coastal sharks generally tended toward warmer, high salinity, shallow bottom waters close to shore. No overarching niche was found for large coastal sharks, but appreciable ontogenetic differences were seen. Most taxa analyzed exhibited declining annual trends in higher quality habitats, particularly during fall months. The analysis provided evidence of shifts north along the Atlantic, to deeper offshore waters in the Atlantic and Gulf of Mexico, and the potential to redistribute in response to multidecadal climate variability for multiple species. The analytical framework described could aid in developing various spatiotemporal management measures, and results provide insight into the habitat characteristics of several species over broad spatiotemporal ranges and through ontogeny. [ABSTRACT FROM AUTHOR]

Simple Summary: Conservation strategies often involve reintroducing species back into parts of their historic range where they no longer occur. Reintroduction efforts can be complicated when there are native species present that might compete with the reintroduced species. Exploring the relationship between the existing and reintroduced species can improve the success of reintroduction efforts. Using information from camera-traps, we examined the extent to which reintroduced oryx and native gazelle display similar activity and space use patterns in Sidi Toui National Park, Tunisia. The two species exhibited minimal spatial overlap within the park and favoured habitats with different vegetation features. Activity patterns relative to time of day and season were similar for oryx and gazelle. Both antelope species were most active at dawn and dusk. Seasonally, activity was lowest for both when conditions were hot and dry and was highest following the rainy season in spring, when new vegetation emerged. The differences in space use patterns can facilitate coexistence between the two species of grazers in Sidi Toui National Park. Habitat diversity can be a key determinant for allowing reintroduced and native species to coexist. Examining the distribution patterns and spatiotemporal niche overlap of sympatric species is crucial for understanding core concepts in community ecology and for the effective management of multi-species habitats within shared landscapes. Using data from 26 camera-traps, recorded over two years (December 2020–November 2022), in Sidi Toui National Park (STNP), Tunisia, we investigate habitat use and activity patterns of the scimitar-horned oryx (n = 1865 captures) and dorcas gazelle (n = 1208 captures). Using information theory and multi-model inference methods, along with the Pianka index, we evaluated the habitat characteristics influencing species distribution and their spatial niche overlap. To delineate daily activity patterns, we applied kernel density estimation. Our findings indicate minimal spatial overlap and distinct environmental factors determining suitable habitats for each species. Furthermore, we found significant temporal niche overlaps, indicative of synchrony in daily activity patterns, with both species showing peak activity at dawn and dusk. Our results indicated that oryx and gazelle differ in at least one dimension of their ecological niche at the current density levels, which contributes to their long-term and stable coexistence in STNP. [ABSTRACT FROM AUTHOR]

Simple Summary: Galloanseres are one of the most widely distributed groups of birds, which occupy different ecological niches and exhibit different evolutionary trends. Mitochondria are widely used in phylogenetic analysis and ecological research due to unique genetic mechanisms and significant physiological functions. Adapting to different environments requires meeting varying energy demands, which is closely related to mitochondria. In this study, we constructed two complete mitogenomes of Aythya baeri and Aythya marila. The phylogenetic and divergence time analysis based on the mitochondrial PCGs were conducted to elucidate the evolutionary process of species within Galloanseres. Additionally, the analysis of selective pressures between the two sister clades, Galliformes and Anseriformes, revealed that different evolutionary directions have shaped distinct evolutionary patterns of mitochondrial genes. The two existing clades of Galloanseres, orders Galliformes (landfowl) and Anseriformes (waterfowl), exhibit dramatically different evolutionary trends. Mitochondria serve as primary sites for energy production in organisms, and numerous studies have revealed their role in biological evolution and ecological adaptation. We assembled the complete mitogenome sequences of two species of the genus Aythya within Anseriformes: Aythya baeri and Aythya marila. A phylogenetic tree was constructed for 142 species within Galloanseres, and their divergence times were inferred. The divergence between Galliformes and Anseriformes occurred ~79.62 million years ago (Mya), followed by rapid evolution and diversification after the Middle Miocene (~13.82 Mya). The analysis of selective pressure indicated that the mitochondrial protein-coding genes (PCGs) of Galloanseres species have predominantly undergone purifying selection. The free-ratio model revealed that the evolutionary rates of COX1 and COX3 were lower than those of the other PCGs, whereas ND2 and ND6 had faster evolutionary rates. The CmC model also indicated that most PCGs in Anseriformes exhibited stronger selective constraints. Our study suggests that the distinct evolutionary trends and energy requirements of Galliformes and Anseriformes drive different evolutionary patterns in the mitogenome. [ABSTRACT FROM AUTHOR]

A new stage in promoting the construction of the Silk Road Economic Belt Core Area, and Xinjiang has been transformed from a relatively closed inland area into an open border. In order to promote the high-quality development of Southern Xinjiang and solve the imbalance contradiction between the development of the Northern Xinjiang and Southern Xinjiang, taking the four districts in Southern Xinjiang as the study area, constructing a high-quality development ecological niche index system of three levels, namely economic, social and ecological, adopting the entropy method to assign weights to the evaluation indexes, and measuring the ecological niche width and the degree of ecological niche overlap of this region in the period from 2011 to 2020. The results show that: Firstly, tourism has the greatest impact on the ecological niche of economic development in state N, with a weighting of 14.18%; Secondly, the ecological status width of economic development in state N demonstrates a structural characteristic of "low level and low gap". The average value of ecological niche width is at class III, indicating a low development status and weak regional influence; Thirdly, the ecological niche overlap of state N is significantly influenced by spatial factors. Regions Z and S are closer together, resulting in higher competition for resource utilization and an average ecological niche overlap at class II. The other two regions are at class III. According to the theory of ecological niche expansion and separation, a specialization separation strategy should be adopted for areas with "low width and high overlap", and a strengthening expansion strategy should be adopted for areas with "low width and low overlap", to optimize the structure of ecological niches and promote high-quality development of the region. [ABSTRACT FROM AUTHOR]

Premise: Functional traits reflect species' responses to environmental variation and the breadth of their ecological niches. Fagus grandifolia and Oreomunnea mexicana have restricted distribution in upper montane cloud forests (1700–2000 m a.s.l.) in Mexico. These species were introduced into plantings at lower elevations (1200–1600 m a.s.l.) that have climates predicted for montane forests in 2050 and 2070. The aim was to relate morphological leaf traits to the ecological niche structure of each species. Methods: Leaf functional traits (leaf area, specific leaf area [SLA], thickness, and toughness) were analyzed in forests and plantings. Atmospheric circulation models and representative concentration pathways (RCPs: 2.6, 4.5, 8.5) were used to assess future climate conditions. Trait–niche relationships were analyzed by measuring the Mahalanobis distance (MD) from the forests and the plantings to the ecological niche centroid (ENC). Results: For both species, leaf area and SLA were higher and toughness lower in plantings at lower elevation relative to those in higher‐elevation forests, and thickness was similar. Leaf traits varied with distance from sites to the ENC. Forests and plantings have different environmental locations regarding the ENC, but forests are closer (MD 0.34–0.58) than plantings (MD 0.50–0.70) for both species. Conclusions: Elevation as a proxy for expected future climate conditions influenced the functional traits of both species, and trait patterns related to the structure of their ecological niches were consistent. The use of distances to the ENC is a promising approach to explore variability in species' functional traits and phenotypic responses in optimal versus marginal environmental conditions. [ABSTRACT FROM AUTHOR]

Migratory bird populations are declining globally at alarming rates. Non-breeding site conditions affect breeding populations, but generalising non-breeding habitat conditions over large spatial regions cannot address potential fine-scale differences across landscapes or local populations. Plumage characteristics can mediate the effects of environmental conditions on individual fitness. However, whether different phenotypes use distinctive non-breeding sites, and whether they respond to non-breeding site conditions differently remains largely unknown. Stable isotopes (δ13C, δ15N, δ2H) of inert tissues are useful to infer habitat characteristics and geographic origins where those tissues were grown. We collected winter-grown feathers from pied flycatchers (Ficedula hypoleuca) on their breeding grounds over several years from males whose dorsal plumage colouration ranged continuously from brown to black and assessed their stable isotope values as proxies of local habitat conditions. Based on feather δ2H profiles we found that browner males spent their non-breeding season in drier habitats than black males. Assignment to origin analysis shows potential regional non-breeding ground separation between differently coloured males. High within-individual repeatability of both δ13C and δ15N indicate the pied flycatcher males return yearly to similar areas. Blacker males were more likely to return to the breeding grounds after dry years compared with brown males. The opposite was found in wet years. Our study demonstrates that different phenotypes are exposed to different non-breeding site conditions which can differentially affect individual survivorship. This has important ramifications for population dynamics under predicted climate change scenarios where especially brown phenotype pied flycatcher males may be under a risk of decreasing. [ABSTRACT FROM AUTHOR]

Ageratum conyzoides L., recognized globally as a noxious weed, holds significant value in traditional medicine, particularly in treating cuts, wounds, and tick infestations. This study focuses on identifying specific germplasms of this plant, rich in therapeutically valuable metabolites, across various phytogeographical zones in India. Using the Reverse Phase High-Performance Liquid Chromatography with Photodiode Array Detection (RP-HPLC-PDA) method, we analyzed 110 samples to quantify five key bioactive markers: Precocene-I (PRC-I), Coumarin (CM), Caryophyllene (CAR), Caryophyllene Oxide (CAO), and Humulene (HUM). Our findings revealed distinct geographical variations in these compounds. The highest concentrations of PRC-I (7.86±1.36 %) was found in sample NAC-12, CM (1.50±0.46 %) and HUM (0.0099±0.0004 %) in NAC-104, while CAR (6.33±0.87 %) and CAO (6.23±0.18 %) were predominant in NAC-01 and NAC-02, respectively. Ecological Niche Modelling (ENM) was used to predict the climatic suitability of regions for high yield of these metabolites. The ENM results showed that annual precipitation (Bio 12), precipitation of the coldest quarter (Bio 19) and minimum temperature of coldest month (Bio 6) were the principal climatic factors influencing metabolite content. Geographically, the Indo-Gangetic plain, Indus plain, and Central India were identified as suitable for higher content of PRC-I, CAO, CAR, whereas the North Eastern region favoured high content of CM and HUM. This study underscores the importance of bioactive marker-based assessment in understanding chemotypic diversity and demonstrates the effective use of ENM in predicting optimal habitats for harvesting specific chemotypes. These insights pave the way for location-specific cultivation strategies and targeted procurement of metabolite-rich germplasms, contributing to sustainable sourcing and conservation efforts, as well as to the advancement of herbal product standardization and efficacy. [Display omitted] • Five bioactive markers were quantified in 110 Ageratum conyzoides samples. • Precocene I was in maximum concentration followed by caryophyllene. • Central India region was favorable for precocene and caryophyllenes. • North Eastern region of India favoured high content of coumarin and humulene. [ABSTRACT FROM AUTHOR]

The origin of paired appendages became one of the most important adaptations of vertebrates, allowing them to lead active lifestyles and explore a wide range of ecological niches. The basic form of paired appendages in evolution is the fins of fishes. The problem of paired appendages has attracted the attention of researchers for more than 150 years. During this time, a number of theories have been proposed, mainly based on morphological data, two of which, the Balfour‐Thacher‐Mivart lateral fold theory and Gegenbaur's gill arch theory, have not lost their relevance. So far, however, none of the proposed ideas has been supported by decisive evidence. The study of the evolutionary history of the appearance and development of paired appendages lies at the intersection of several disciplines and involves the synthesis of paleontological, morphological, embryological, and genetic data. In this review, we attempt to summarize and discuss the results accumulated in these fields and to analyze the theories put forward regarding the prerequisites and mechanisms that gave rise to paired fins and limbs in vertebrates. [ABSTRACT FROM AUTHOR]

Habitat fragmentation can facilitate local adaptation of species to heterogeneous environments and affect population demographic history. To understand the factors influencing evolutionary dynamics, such as climatic fluctuations and complex geomorphological features, we used 18 chloroplast microsatellites, 15 nuclear microsatellites, three chloroplast fragments, and two nuclear regions to explore the genetic structure and phylogeographical history of Pseudotaxus chienii. Furthermore, its current and past distributions were constructed based on ecological niche modelling. Moderate to high levels of genetic diversity were found at the species level. Precipitation was a decisive factor influencing the genetic structure of P. chienii. In addition, local adaptation to heterogeneous environments also contributed to maintain the fragmented distribution. Finally, incomplete lineage sorting led to the cyto-nuclear discordance. Overall, we show that pre-Quaternary and Quaternary climatic fluctuations and restricted gene flow exerted significant effects on the formation and maintenance of the fragmented distribution of P. chienii. The study provides new insights into the evolutionary history of plants in subtropical China. [ABSTRACT FROM AUTHOR]

Aim: Oceanic sharks play an important role in maintaining the stability and biodiversity of marine ecosystems, and yet they are among the most threatened taxa worldwide. Currently, large spatial‐scale distribution patterns and conservation gaps are poorly known for most species since they are challenging to study. To address the problem, we here use an integrated approach with an illustration with the blue shark (Prionace glauca), a common bycatch oceanic species. Location: Indo‐Western Pacific Ocean (IWPO). Methods: We first collated decades of species occurrences and marine environmental datasets from open‐access sources. We then applied ensembled species distribution models (SDMs) to predict its seasonal distributions and evaluated the model performance using true skill statistic (TSS) and area under the receiver‐operating characteristic curve (AUC). We finally conducted spatial analyses (e.g. bivariate hotspot analyses) to identify conservation gaps/opportunities based on the predicted distribution maps and two additional datasets, namely, marine protected areas (MPAs) and fishing effort. Results: (1) Both seasonal SDMs performed well (mean TSS > 0.8, AUC > 0.95), and the results suggested that blue sharks were widely distributed in the IWPO with some seasonal differences in ecological niches and distributions (mainly in the West Indian Ocean and the Northwest Pacific Ocean); (2) large MPAs and shark sanctuaries covered comparable, small portions (4%–9%) of blue shark habitats, but these locations (in MPAs and sanctuaries) varied between seasons; (3) fishery‐shark conflict hotspots also varied between seasons with some located in or close to large MPAs and sanctuaries. Main conclusions: We provide seasonal (cold vs. warm) distribution maps of blue sharks across the IWPO to advance their conservation and management. We highlight the importance of strengthening management both in and near large MPAs and shark sanctuaries. Our study contributes a feasible integrated approach to reveal seasonal distribution patterns and conservation opportunities for oceanic sharks. [ABSTRACT FROM AUTHOR]

Aim: The abundant niche‐centre hypothesis has been used to describe patterns of species abundance relative to position in ecological niche space. Such relationships, however, are inconsistently recovered and may be obscured due to non‐equilibrium distributions, such as those caused novel interactions with exotic species. Here, we explore patterns of fitness for the nine‐spotted lady (Coccinella novemnotata) following the introduction of an exotic competitor, the seven‐spotted lady beetle (C. septempunctata). We examine how niche overlap between species may be causing a range reduction for C. novemnotata through a modified abundant niche‐centre relationship. Location: North America. Methods: We applied a time‐oriented view of the abundant niche‐centre relationship for C. novemnotata, both before and after the introduction of C. septempunctata. We tested for both niche overlap and correlation between C. novemnotata body size (i.e. fitness) and the distance from its niche centroid relative to the invasion status of C. septempunctata. Results: The current niche space currently occupied by C. novemnotata is equivalent to its historic niche but has shifted to avoid overlap with C. septempunctata. A historic abundant niche‐centre relationship with larger individuals closer to the niche centroid was observed for C. novemnotata. However, this pattern changed to have smaller beetles near the niche centroid when the current distribution was considered. Main Conclusions: Fitness patterns displayed by C. novemnotata are effectively described by the abundant niche‐centre hypothesis. However, this relationship was modified with the introduction of C. septempunctata. Coccinella novemnotata is not excluded from previously suitable areas that correspond to niche space nearest to its niche centroid. Abundant niche‐centre relationships may provide strong predictions of species' fitness across a species geographic range; however, these relationships may be obscured by novel pressures resulting in non‐equilibrium states. [ABSTRACT FROM AUTHOR]

Aim: As climate change increases the frequency and severity of droughts in many regions, conservation during drought is becoming a major challenge for ecologists. Droughts are multidimensional climate events whose impacts may be moderated by changes in temperature, water availability or food availability, or some combination of these. Simultaneously, other stressors such as extensive anthropogenic landscape modification may synergize with drought. Useful observational models for guiding conservation decision‐making during drought require multidimensional, dynamic representations to disentangle possible drought impacts, and consequently, they will require large, highly resolved data sets. In this paper, we develop a two‐stage predictive framework for assessing how drought impacts vary with species, habitats and climate pathways. Location: Central Valley, California, USA. Methods: We used a two‐stage counterfactual analysis combining predictive linear mixed models and N‐mixture models to characterize the multidimensional impacts of drought on 66 bird species. We analysed counts from the eBird participatory science data set between 2010 and 2019 and produced species‐ and habitat‐specific estimates of the impact of drought on relative abundance. Results: We found that while fewer than a quarter (16/66) of species experienced abundance declines during drought, nearly half of all species (27/66) changed their habitat associations during drought. Among species that shifted their habitat associations, the use of natural habitats declined during drought while use of developed habitat and perennial agricultural habitat increased. Main Conclusions: Our findings suggest that birds take advantage of agricultural and developed land with artificial irrigation and heat‐buffering microhabitat structure, such as in orchards or parks, to buffer drought impacts. A working lands approach that promotes biodiversity and mitigates stressors across a human‐induced water gradient will be critical for conserving birds during drought. [ABSTRACT FROM AUTHOR]

Sky Islands present unique landscapes for organismal evolution because they comprise high mountain peaks separated by low valleys with vastly different environmental conditions. The Espinhaço Mountain Range in eastern Brazil is formed of groups of Sky Islands in the states of Minas Gerais and Bahia. Several phylogeographic studies have discovered strong genetic structure among populations of organisms occupying the campo rupestre (rupestrian fields) in the mountains of the Espinhaço. In this study, we aimed to test the hypothesis of spatio-temporal structuring of populations of Scinax curicica in the campo rupestre of the Espinhaço. We recovered three lineages of S. curicica : one lineage occurs in the north portion of the Espinhaço (North Lineage) in an area called Chapada Diamantina, and other two occur in the south portion of the Espinhaço (South 1 and South 2 Lineages) in Minas Gerais. All three lineages showed stable population sizes through time, probably due to the climatic stability of mountaintop areas, which was supported by ecological niche modelling. [ABSTRACT FROM AUTHOR]

The construction of well-facilitated farmland plays a vital role in ensuring national food security. Therefore, our study sought to facilitate the evaluation of farmland constructions and site selection. To achieve this, we conducted a case study in the Fengxiang District of Baoji City and developed a suitability evaluation model based on the ecological niche theory. This model considered four key factors: soil conditions, infrastructure construction, landscape patterns, and ecological constraints. Through a comparison of realistic and ideal ecological niches for various factors, we established a diagnostic model that identifies obstacle factors along with their respective obstacle degrees and ecological niches. By combining suitability, obstacle level, and transformation difficulty, we categorized different well-facilitated farmland construction priority zones, ranging from the most suitable and easiest to implement to the least suitable and more challenging. A total of 20,669 farmland patches were quantitatively evaluated and our findings indicated that the overall suitability of farmland construction in Fengxiang District is good. Cultivated land in the priority construction areas accounts for 47.49%, demonstrating high suitability for construction and the potential to reach optimal regional levels with minor adjustments. Our analysis revealed that the main obstacle factors in the landscape pattern dimension were mainly at the field scale, whereas the key obstacle factors in the ecological constraints dimension were related to irrigation water sources and slope gradients. Importantly, the evaluation results were generally consistent with the real situation, thus validating the scientific robustness and realistic nature of the ecological niche model for assessing construction suitability. Overall, our proposed approach can be used to effectively evaluate the suitability of regional well-facilitated farmland construction. These findings can serve as a solid basis for making scientifically informed decisions when selecting sites for well-facilitated farmland construction, contributing to its successful, efficient, and cost-effective implementation. [ABSTRACT FROM AUTHOR]

Microbial communities that reduce nitrous oxide (N2O) are divided into two clades, nosZI and nosZII. These clades significantly differ in their ecological niches and their implications for N2O emissions in terrestrial environments. However, our understanding of N2O reducers in aquatic systems is currently limited. This study investigated the relative abundance and diversity of nosZI‐ and nosZII‐type N2O reducers in rivers and their impact on N2O emissions. Our findings revealed that stream sediments possess a high capacity for N2O reduction, surpassing N2O production under high N2O/NO3‐ ratio conditions. This study, along with others in freshwater systems, demonstrated that nosZI marginally dominates more often in rivers. While microbes containing either nosZI and nosZII were crucial in reducing N2O emissions, the net contribution of nosZII‐containing microbes was more significant. This can be attributed to the nir gene co‐occurring more frequently with the nosZI gene than with the nosZII gene. The diversity within each clade also played a role, with nosZII species being more likely to function as N2O sinks in streams with higher N2O concentrations. Overall, our findings provide a foundation for a better understanding of the biogeography of stream N2O reducers and their effects on N2O emissions. [ABSTRACT FROM AUTHOR]

It has been suggested that the American black bear (Ursus americanus) may be responsible for a significant number of purported sightings of an alleged unknown species of hominid in North America. Previous analyses have identified a correlation between 'sasquatch' or 'bigfoot' sightings and black bear populations in the Pacific Northwest using ecological niche models and simple models of expected animal sightings. The present study expands the analysis to the entire US and Canada by modelling sasquatch sightings and bear populations in each state/province while adjusting for human population and forest area in a generalized linear model. Sasquatch sightings were statistically significantly associated with bear populations such that, on the average, every 1000 bear increase in the bear population is associated with a 4% (95% CI: 1–7%) increase in sasquatch sightings. Thus, as black bear populations increase, sasquatch sightings are expected to increase. On average, across all states and provinces in 2006, after controlling for human population and forest area, there were approximately 5000 bears per sasquatch sighting. Based on statistical considerations, it is likely that many supposed sasquatch are really misidentified known forms. If bigfoot is there, it could be a bear. [ABSTRACT FROM AUTHOR]

Co‐occurrence between species may be mediated by ecological differences or competitive interactions, but the nature of these interactions can vary across spatial scales. At coarse scales, species may appear to broadly co‐occur, but at fine scales, particularly for species with small home ranges, species may utilize different aspects of the microhabitat such that co‐occurrence is limited and competitive interactions are reduced or eliminated. We investigated the microhabitat use of two morphologically and ecologically similar woodland salamanders (the Red‐backed Salamander, Plethodon cinereus, and the Northern Ravine Salamander, P. electromorphus) that are distributed throughout the Alleghany Plateau in eastern North America to determine whether they partition habitat at finer scales. We also tested if P. electromorphus is a specialist on habitat types that allow it to exclude P. cinereus, or if P. electromorphus uses lower quality habitat as a refuge to avoid P. cinereus. At a site of microsympatry, we repeatedly sampled plots during two seasons, each within a different area of the landscape, and used occupancy and abundance modeling to assess the extent of co‐occurrence and test whether the species use different microhabitat conditions. Plethodon cinereus greatly outnumbered P. electromorphus and occupied a greater proportion of plots, most plots where we detected P. electromorphus we also detected P. cinereus. In contrast to patterns documented in some montane species pairs, in which a high‐elevation habitat specialist excludes a low‐elevation generalist, we found that P. electromorphus primarily used microhabitat conditions favorable for both species, such as north‐facing slopes, yet did not have a negative effect on the abundances of P. cinereus. In the presence of an abundant competitor, microhabitat use of the less abundant species may narrow toward optimal conditions with sufficient resources to facilitate co‐occurrence. [ABSTRACT FROM AUTHOR]

Competition is a prominent mechanism driving population dynamics and structuring community assemblage, which can be investigated by linking shifts in species' ecological niche and the densities of sympatric species because the ecological release from competitive constraints is a density‐dependent process. In this work we determine how a steppe passerine community segregates their ecological niches and evaluate the role of competition in inducing changes in the ecological niche of species. We built multidimensional ecological niches (with Gaussian kernel density estimators) using data on the habitat features used by 10 bird species collected from seven sites in the natural steppes of Central Spain over 2 consecutive years. We computed distance and niche similarity metrics to explore the ecological niche partitioning of the bird community. Next, we ran multivariate linear regression models to evaluate the effects of conspecific and heterospecific density (as proxies of intraspecific and interspecific competition, respectively) on niche breadth and/or position of the three most abundant species. We found low niche overlap in the community assemblage but varying levels of niche similarity among pairs of species, which could increase the likelihood of current competition operating in the community. However, we found no effect of heterospecific density on niche breadth or position, although conspecific density was negatively related to niche breadth. Contrary to predictions of competition theory, increased density of conspecifics caused niche contraction. Our results from a multispecies system contribute to advanced knowledge of the biotic mechanisms structuring wildlife communities within the framework of ecological niche theory. [ABSTRACT FROM AUTHOR]

Background and Aims The Greater Cape Floristic Region is one of the world's biodiversity hotspots and is considered poor in polyploids. To test this assumption, ploidy variation was investigated in a widespread Cape shrub, Dicerothamnus rhinocerotis (renosterbos, Asteraceae). The aim was to elucidate the cytotype distribution and population composition across the species range, and to assess differences in morphology, environmental niches and genetics. Methods Ploidy level and genome size were determined via flow cytometry and cytotype assignment was confirmed by chromosome counting. Restriction site-associated DNA sequencing (RADseq) analyses were used to infer genetic relationships. Cytotype climatic and environmental niches were compared using a range of environmental layers and a soil model, while morphological differences were examined using multivariate methods. Key Results The survey of 171 populations and 2370 individuals showed that the species comprises diploid and tetraploid cytotypes, no intermediates and only 16.8 % of mixed populations. Mean 2C values were 1.80–2.06 pg for diploids and 3.48–3.80 pg for tetraploids, with very similar monoploid genome sizes. Intra-cytotype variation showed a significant positive correlation with altitude and longitude in both cytotypes and with latitude in diploids. Although niches of both cytotypes were highly equivalent and similar, their optima and breadth were shifted due to differences mainly in isothermality and available water capacity. Morphometric analyses showed significant differences in the leaves and corolla traits, the number of florets per capitulum, and cypsela dimensions between the two cytotypes. Genetic analyses revealed four groups, three of them including both cytotypes. Conclusions Dicerothamnus rhinocerotis includes two distinct cytotypes that are genetically similar. While tetraploids arise several times independently within different genetic groups, morphological and ecological differences are evident between cytotypes. Our results open up new avenues for questions regarding the importance of ploidy in the megadiverse Cape flora, and exemplify the need for population-based studies focused on ploidy variation. [ABSTRACT FROM AUTHOR]

Background and Aims Geoxyles, a distinctive feature of Afrotropical savannas and grasslands, survive recurrent disturbances by resprouting subshrub branches from large below-ground woody structures. Underground trees are a type of geoxyle that independently evolved within woody genera of at least 40 plant families in Africa. The environmental limits and determinants of underground tree biogeography are poorly understood, with the relative influence of frost and fire debated in particular. We aim to quantify variability in the niche of underground tree species relative to their taller, woody tree/shrub congeners. Methods Using occurrence records of four Afrotropical genera, Parinari (Chrysobalanaceae), Ozoroa (Anacardiaceae), Syzygium (Myrtaceae) and Lannea (Anacardiaceae), and environmental data of nine climate and disturbance variables, the biogeography and niche of underground trees are compared with their open and closed ecosystem congeners. Key Results Along multiple environmental gradients and in a multidimensional environmental space, underground trees inhabit significantly distinct and extreme environments relative to open and closed ecosystem congeners. Niche overlap is low among underground trees and their congeners, and also among underground trees of the four genera. Of the study taxa, Parinari underground trees inhabit hotter, drier and more seasonal environments where herbivory pressure is greatest. Ozoroa underground trees occupy relatively more fire-prone environments, while Syzygium underground trees sustain the highest frost frequency and occur in relatively wetter conditions with seasonal waterlogging. Lannea underground trees are associated with the lowest temperatures, highest precipitation, and varying exposure to disturbance. Conclusions While underground trees exhibit repeated convergent evolution, varied environments shape the ecology and biogeography of this iconic plant functional group. The multiplicity of extreme environments related to fire, frost, herbivory and waterlogging that different underground tree taxa occupy, and the distinctiveness of these environments, should be recognized in the management of African grassy ecosystems. [ABSTRACT FROM AUTHOR]

The tree genus Dimorphandra (Fabaceae), which contains 26 species divided into three subgenera, was studied using DNA sequence data from six chloroplast genome regions (cpDNA) and the nuclear internal transcribed spacer (ITS). The analyses, which included Bayesian phylogenies and haplotype networks, ancestral area reconstructions, and ecological niche modeling, allowed for exploring the evolutionary history of Dimorphandra. Within the subgenus Phaneropsia, the cpDNA sequence data were more closely-related to species from the genus Mora, while the ITS sequence data displayed a closer phylogenetic relationship with the subgenus Pocillum. This incongruence may be due to incomplete lineage sorting associated with ancient polymorphisms. The Amazonian Dimophandra lineages were highly polymorphic and divergent, while those from the Cerrado and the Atlantic Forest had low levels of polymorphisms. The Amazon likely gave rise to the Dimophandra lineage that produced the Cerrado species, while a Cerrado lineage likely gave rise to the Atlantic Forest species. Habitat shifts were identified as a key factor in shaping the late evolutionary history of Dimorphandra. [ABSTRACT FROM AUTHOR]

Biological invasions pose significant threats to biodiversity, with invasive species spread often facilitated by human activities. Consequently, this research utilized ecological niche modeling (ENM) to overcome this limitation and map the potential suitability of Microtheca ochroloma Stål, 1860 and Microtheca semilaevis Stål, 1860, which have been evaluated as potential insect pests in the Americas, zones for four genera of Brassicaceae, which include globally cultivated species such as Sinapis L., Raphanus L., Eruca Mill., and Brassica L. We utilized multiple methods to forecast the ecological habitat of Microtheca Stål, 1860 species based on distribution data and various environmental indicators. Our models, exhibiting high-performance metrics (TSS ranging from 0.84 to 0.96), revealed extensive environmental suitability for these species across the Americas, including previously unreported regions. The predicted zones overlapped significantly with areas where Brassicaceae crops were grown. Contrary to some previous assertions, our findings suggest that while these Microtheca species are recognized pests on these crops, their consistent widespread damage may be overstated. Nevertheless, their invasive potential could have broad ecological impacts, including biodiversity loss. Our research emphasizes the need for focused sampling in potential distribution zones and underlines the value of integrating ENM in predicting and managing invasive species spread. [ABSTRACT FROM AUTHOR]

Aim: Animal communities around the world are responding to climate change by altering their taxonomic composition, mainly through an increase in the colonisation rate of warm‐dwelling species and the local extinction of cold‐dwelling ones. We assessed whether the taxonomic composition of bird assemblages in peninsular Spain has changed in accordance with the recent increase in temperature. We also evaluated the role of species thermal affinities and population dynamics on these changes. Location: Peninsular Spain. Taxon: Birds. Methods: We compared assemblages reported in the last Spanish breeding bird atlases (1998–2002 vs. 2014–2018) in 10 × 10 km squares. We described species' thermal niches by overlaying global species breeding distributions and world temperature metrics (based on mean, minimum, maximum and range), and then aggregated them to obtain a set of community thermal indices for each assemblage (CTIs and CTR for ranges). Long‐term average temperatures and local current temperatures were related to changes in CTIs using spatial GLMMs, which considered habitat change. We identified the species most responsible for variation in assemblages and regressed species' influence on thermal affinities and population dynamics. Results: CTIs increased with temperature and warm‐dwelling species became more prevalent to the detriment of cold‐dwelling ones. However, we found a counteracting effect of temperature and habitat. Cold‐dwelling forest species were among the most influential species, mainly through colonisation, while warm‐dwelling farmland species contributed through local extinctions (both attenuated local increases in CTI). The mean thermal breadth of assemblages (CTR) decreased with temperatures. Main conclusions: The taxonomic composition of bird assemblages shifted in line with the main expectations due to global change (thermophilisation), mainly due to local colonisation of warm‐dwelling species, although it did not show the pattern of thermal homogenisation suggested elsewhere. Our results add further evidence of the interplay between climate warming and land‐use change in the ongoing adjustment of animal communities. [ABSTRACT FROM AUTHOR]

Aim: We aimed to understand how biogeographical processes and moisture niche ecology contributed to the spatio‐temporal diversification dynamics in the land snail genus Vertigo. Location: Global (North America, Europe, Asia, Africa). Time Period: Cenozoic era. Major Taxa Studied: Minute terrestrial snails of the genus Vertigo. Methods: We reconstructed a time‐calibrated phylogeny of 94 Vertigo taxa (~85% of all known extant species) based on mitochondrial and nuclear DNA data. Leveraging this phylogeny with distributional and ecological data from >7000 populations, we performed biogeographic and ecological modelling to investigate evolutionary mechanisms of global Vertigo diversification. Results: Vertigo has diversified since the Early Eocene, ca. 47.6 Ma (95% HPD = 46.0–52.7), with its six subgenera originating from the Late Eocene (30.2–48.7 Ma) to the Early Miocene (13.3–23.0 Ma). Species diversity accumulated linearly, with a slight increase 35–30 and 25–20 Ma, coinciding with the emergence of most subgenera and northern hemisphere cooling, respectively. Biogeographic modelling indicated that most diversification events occurred in sympatry (no range modification), but that rare founder events drove global diversification. Soil moisture conditions, a major variable defining Vertigo niches, displayed significant phylogenetic signal, but varied less among subgenera relative to within. Shifts in biogeographical ranges and moisture niches (or the absence thereof) were significantly associated at macroevolutionary scales, with most niche shifts upon sympatric cladogenesis and hardly any upon founder‐event speciation. Main Conclusions: Our results indicate that ecological shifts in soil moisture niches occasionally drove cladogenesis in sympatry and anagenetic range extensions, but that long‐distance dispersal was mainly successful in the absence of such shifts. A combination of neutral (founder events and drift) and selective mechanisms (adaptive habitat shifts) has determined the macroevolutionary success of Vertigo. Our results imply that species with high niche fidelity or fewer opportunities for long‐distance dispersal will be more vulnerable to future anthropogenic stressors. [ABSTRACT FROM AUTHOR]

The diversity‐habitat complexity relationship has been utilised widely in conservation and biodiversity enhancement interventions, but few studies have attempted to tease apart the components of complexity that drive this relationship. The ecological engineering of seawalls is one area where this topic has advanced, albeit not often at scales relevant to fish.We constructed habitat enhancement units (Simple, Complex and Freestyle 'fish houses') out of hollow concrete blocks and installed them at the base of tropical rip‐rap seawalls. Simple and Complex fish houses were cuboid, had the same surface area and volume and included 100 holes (microhabitats). The holes in Simple fish houses were all the same size, whereas 25 size variations were used in the Complex design (volume‐independent manipulation of a single complexity element). The Freestyle fish house was non‐cuboid and had more overall volume, microhabitat types and sizes.We examined the volume‐independent (Simple vs. Complex fish houses) and volume‐dependent (Freestyle fish house) effects of microhabitat complexity on fish taxonomic and functional assemblage metrics at two spatial scales and across diel cycles. We also investigated diurnal and nocturnal fish‐microhabitat size relationships.There was a modest, but not significant, volume‐independent effect of complexity on fish assemblages. The Freestyle design, however, supported significantly greater abundance, species richness, and distinct taxonomic and functional compositions. These results were dependent on spatial scales and diel cycles. Diel variation in fish activity patterns resulted in stronger size‐matching relationships between fish and microhabitats at night than during the day.Synthesis and applications. Our study shows that, to enhance fish diversity, it is important to provide three‐dimensional habitat architecture that incorporates a wide range of microhabitat sizes and types. Our findings also highlight some key considerations when assessing the performance of intervention designs, including spatial‐scale dependent effects of structural complexity, diel variation in fish‐microhabitat relationships, and choice of intervention assessment metric (i.e. taxonomic vs. functional diversity). [ABSTRACT FROM AUTHOR]

Enantiornithines were the dominant birds of the Mesozoic, but understanding of their diet is still tenuous. We introduce new data on the enantiornithine family Bohaiornithidae, famous for their large size and powerfully built teeth and claws. In tandem with previously published data, we comment on the breadth of enantiornithine ecology and potential patterns in which it evolved. Body mass, jaw mechanical advantage, finite element analysis of the jaw, and traditional morphometrics of the claws and skull are compared between bohaiornithids and living birds. We find bohaiornithids to be more ecologically diverse than any other enantiornithine family: Bohaiornis and Parabohaiornis are similar to living plant-eating birds; Longusunguis resembles raptorial carnivores; Zhouornis is similar to both fruit-eating birds and generalist feeders; and Shenqiornis and Sulcavis plausibly ate fish, plants, or a mix of both. We predict the ancestral enantiornithine bird to have been a generalist which ate a wide variety of foods. However, more quantitative data from across the enantiornithine tree is needed to refine this prediction. By the Early Cretaceous, enantiornithine birds had diversified into a variety of ecological niches like crown birds after the K-Pg extinction, adding to the evidence that traits unique to crown birds cannot completely explain their ecological success. [ABSTRACT FROM AUTHOR]

Morphological diversity within organisms can arise from factors other than genetic diversity alone. Local adaptations and combinations of various factors are also involved in shaping morphology. We investigated the relationship between morphological diversity and ecological niche divergence within two related tropical stream‐dwelling newt species from Indochina: Paramesotriton deloustali and P. guangxiensis. We identified sexual dimorphism within both species and a significantly larger body size in P. deloustali than in P. guangxiensis. Our findings highlighted that climatic variables strongly influence Asian warty newt distribution, indicating the potential effects of climate change on tropical newt populations. Furthermore, we identified significant intra‐ and interspecific morphological and niche differentiation across five populations of the two newt species, suggesting that newt morphology is responsive to environmental factors. A significant negative relationship was observed only between ecological niche similarity and geographic distance among various combinations of factors, indicating that the distinct morphology of the study species mirrors ecological adaptation. [ABSTRACT FROM AUTHOR]

A mechanistic understanding of algal growth is essential for maintaining a sustainable environment in an era of climate change and population expansion. It is known that algal growth is tightly controlled by complex interactive physical and chemical conditions. Many mathematical models have been proposed to describe the relation of algal growth and environmental parameters, but experimental verification has been difficult due to the lack of tools to measure cell growth under precise physical and chemical conditions. As such, current models depend on the specific testing systems, and the fitted growth kinetic constants vary widely for the same organisms in the existing literature. Here, we present a microfluidic platform where both light intensity and nutrient gradients can be well controlled for algal cell growth studies. In particular, light shading is avoided, a common problem in macroscale assays. Our results revealed that light and nitrogen colimit the growth of algal cells, with each contributing a Monod growth kinetic term in a multiplicative model. We argue that the microfluidic platform can lead towards a general culture system independent algal growth model with systematic screening of many environmental parameters. Our work advances technology for algal cell growth studies and provides essential information for future bioreactor designs and ecological predictions. [ABSTRACT FROM AUTHOR]

Aim Location Taxon Methods Results Main Conclusions The continuous development of statistical tools applied to ecology has contributed to great advances for modelling species' niches and distributions from opportunistic observations. However, as these observations are subject to biases caused by spatial variation in sampling effort, ecological niche models (ENMs) are also frequently biased. Among several bias correction methods that have been proposed, spatial filtering—imposing a minimum distance between occurrences—is widely used, yet lacks clear guidelines for choosing the filtering distance. Here, we aimed to explore the impact of spatial filtering distances on the performance of ENMs.Europe.Virtual species.We applied ENMs to two virtual species with contrasting levels of specialisation, across a spectrum of modelling conditions, bias types and sample sizes.Models applied to the specialist species had on average a lower performance than those applied to the generalist species. Using a biased sample reduced model performance, especially when the bias was strong, and when the sample size was large. In many cases, spatial filtering failed to improve model performance or even reduced it. We did find an improvement for the generalist species modelled with large and strongly biased datasets. However, there was no optimal filtering distance, as this improvement was linearly and positively associated with filtering distance. Moreover, because the initial bias was strong and the filtered dataset became very small, the resulting models had only very low accuracy.Our results suggest that there is no optimal filtering distance for dealing with sampling bias in ENMs, and that spatial filtering never improves model performance enough to draw accurate predictions. We therefore recommend spatial filtering to be employed cautiously, only when enough data are available, and bearing in mind that its effectiveness remains highly uncertain. [ABSTRACT FROM AUTHOR]

Summary: Organisms use diverse strategies to thrive in varying habitats. While life history theory partly explains these relationships, the combined impact of resource availability and disturbance frequency on life form strategy evolution has received limited attention.We use Chamaecrista species, a legume plant lineage with a high diversity of plant life forms in the Neotropics, and employ ecological niche modeling and comparative phylogenetic methods to examine the correlated evolution of plant life forms and environmental niches.Chamaephytes and phanerophytes have optima in environments characterized by moderate water and nutrient availability coupled with infrequent fire disturbances. By contrast, annual plants thrive in environments with scarce water and nutrients, alongside frequent fire disturbances. Similarly, geophyte species also show increased resistance to frequent fire disturbances, although they thrive in resource‐rich environments.Our findings shed light on the evolution of plant strategies along environmental gradients, highlighting that annuals and geophytes respond differently to high incidences of fire disturbances, with one enduring it as seeds in a resource‐limited habitat and the other relying on reserves and root resprouting systems in resource‐abundant habitats. Furthermore, it deepens our understanding of how organisms evolve associated with their habitats, emphasizing a constraint posed by low‐resource and high‐disturbance environments. [ABSTRACT FROM AUTHOR]

The marine animal phylum Placozoa is characterized by a poorly explored cryptic biodiversity combined with very limited knowledge of their ecology. While placozoans are typically found as part of the epibenthos of coastal waters, known placozoan predators, namely small, shell‐less sea slugs belonging to the family Rhodopidae (Mollusca: Gastropoda: Heterobranchia), inhabit the interstitium of seafloor sediment. In order to gain further insights into this predator–prey relationship and to expand our understanding of placozoan ecological niches, we screened publicly available whole‐body metagenomic data from two rhodopid specimens collected from coastal sediments. Our analysis not only revealed the signatures of three previously unknown placozoan lineages in these sea slug samples but also enabled the assembly of three complete and two partial mitochondrial chromosomes belonging to four previously described placozoan genera, substantially extending the picture of placozoan biodiversity. Our findings further refine the molecular phylogeny of the Placozoa, corroborate the recently established taxonomic ranks in this phylum, and provide molecular support that known placozoan clades should be referred to as genera. We finally discuss the main finding of our study – the presence of placozoans in the sea floor sediment interstitium – in the context of their ecological, biological, and natural history implications. [ABSTRACT FROM AUTHOR]