Search

BACKGROUND: Dendroctonus valens along with its symbiotic fungi have caused unprecedented damage to pines in China. Leptographium procerum, its primary symbiotic fungus, facilitates the invasion and colonization of the pest, thereby aggravating ecological threats. Assessing shifts in the niches and ranges of D. valens and its symbiotic fungus could provide a valuable basis for pest control. Here, we conducted niche comparisons between native and invasive populations of D. valens. Then, we employed standard ecological niche models and ensembles of small models to predict the potential distributions of D. valens and L. procerum under climate change conditions and to estimate areas of overlap. RESULTS: The niche of invasive population of D. valens in Chinese mainland only occupied a limited portion of the niche of native population in North America, leaving a substantial native niche unfilled and without any niche expansion. The suitable regions for D. valens are predicted in central and southern North America and central and northeastern Chinese mainland. The overlap with the suitable regions of L. procerum included eastern North America and the central and northeastern Chinese mainland under historical climatic scenarios. The regions susceptible to their symbiotic damage will shift northward in response to future climate change. CONCLUSIONS: Projected distributions of D. valens and its symbiotic fungus, along with areas vulnerable to their symbiotic damage, provide essential insights for devising strategies against this association. Additionally, our study contributes to comprehending how biogeographic approaches aid in estimating potential risks of pest–pathogen interactions in forests within a warming world. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Background: Cache Valley virus (CVV) is an understudied Orthobunyavirus with a high spillover transmission potential due to its wide geographical distribution and large number of associated hosts and vectors. Although CVV is known to be widely distributed throughout North America, no studies have explored its geography or employed computational methods to explore the mammal and mosquito species likely participating in the CVV sylvatic cycle. Methods: We used a literature review and online databases to compile locality data for CVV and its potential vectors and hosts. We linked location data points with climatic data via ecological niche modeling to estimate the geographical range of CVV and hotspots of transmission risk. We used background similarity tests to identify likely CVV mosquito vectors and mammal hosts to detect ecological signals from CVV sylvatic transmission. Results: CVV distribution maps revealed a widespread potential viral occurrence throughout North America. Ecological niche models identified areas with climate, vectors, and hosts suitable to maintain CVV transmission. Our background similarity tests identified Aedes vexans, Culiseta inornata, and Culex tarsalis as the most likely vectors and Odocoileus virginianus (white-tailed deer) as the most likely host sustaining sylvatic transmission. Conclusions: CVV has a continental-level, widespread transmission potential. Large areas of North America have suitable climate, vectors, and hosts for CVV emergence, establishment, and spread. We identified geographical hotspots that have no confirmed CVV reports to date and, in view of CVV misdiagnosis or underreporting, can guide future surveillance to specific localities and species. [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]

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]

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: Description of the driving forces for genetic divergence is important for understanding spatial pattern of biodiversity and development of conservation plans. Paleo‐climate, geographical barriers and habitat heterogeneity are considered to be the main influential factors; however, an integrative study is still lacking to reveal their interactions. Location: Eastern North America. Methods: Here, we generated MIG‐seq SNPs of 403 Sanguinaria canadensis samples and seven plastome data. The methods of phylogeography and landscape genomics were applied to infer their genetic divergence, demography, species distribution modelling, ecological differentiation and local adaptation. Results: We identified three distinct genetic lineages corresponding to geographical distributions isolated by the Appalachian Mountains and the Mississippi River. Ecological niche modelling and population demographic inference demonstrated that the response of S. canadensis to Pleistocene climate changes was consistent with the pattern of southward contraction during the ice age and northward recolonization during the inter−/postglacial period. Isolation in multiple southern refugia was a key factor resulting in the genetic divergence, whereas secondary contact triggered by repeated range shifts allowed gene flow among different lineages. A greater effect of isolation‐by‐environment than isolation‐by‐distance was founded, which suggested heterogeneous environment was also a promotor of genetic differentiation. Candidate adaptive loci related to transposable elements were identified under the influence of divergent environmental selection. Ecological niche divergence also reflected adaptation to different environments. Main Conclusions: This study revealed that genetic divergence has occurred within S. canadensis populations under the combined effect of paleo‐climate, geographical barriers and habitat heterogeneity, and emphasized the necessity of establishing different conservation units in future biological conservation and management work. [ABSTRACT FROM AUTHOR]

One of the drivers of life's diversification has been the emergence of "evolutionary innovations": The evolution of traits that grant access to underused ecological niches. Since ecological interactions can occur separately from mating, mating-related traits have not traditionally been considered factors in niche evolution. However, in order to persist in their environment, animals need to successfully mate just as much as they need to survive. Innovations that facilitate mating activity may therefore be an overlooked determinant of species' ecological limits. Here, we show that species' historical niches and responses to contemporary climate change are shaped by an innovation involved in mating--a waxy, ultra-violet-reflective pruinescence produced by male dragonflies. Physiological experiments in two species demonstrate that pruinescence reduces heating and water loss. Phylogenetic analyses show that pruinescence is gained after taxa begin adopting a thermohydrically stressful mating behavior. Further comparative analyses reveal that pruinose species are more likely to breed in exposed, open-canopy microhabitats. Biogeographic analyses uncover that pruinose species occupy warmer and drier regions in North America. Citizen-science observations of Pachydiplax longipennis suggest that the extent of pruinescence can be optimized to match the local conditions. Finally, temporal analyses indicate that pruinose species have been buffered against con-temporary climate change. Overall, these historical and contemporary patterns show that successful mating can shape species' niche limits in the same way as growth and survival. [ABSTRACT FROM AUTHOR]

The big‐bracted dogwood clade Benthamidia of Cornus is a typical example of the well‐known eastern Asia (EA) and North America (NA) floristic disjunction, with greater species diversity in EA than in NA. The lineage provides an opportunity to explore factors contributing to the plant diversity unevenness between EA and NA and test hypotheses on the origin of disjunct distribution from a phylogenetic perspective. We generated RAD‐seq data, conducted phylogenomic and biogeographic analyses for the clade with sampling of all species (9) and subspecies (10) currently recognized in floras. We also assessed species delineation and calculated phylogenetic diversity to evaluate the diversity unevenness between EA and NA. Finally, we examined variation of diversification rates and ecological niches on the phylogeny to explore potential causes underlying the observed diversity pattern. Our results revealed phylogenetic relationships congruent with previous studies and suggested a trans‐Beringian ancestral distribution of the clade Benthamidia in the mid‐Oligocene, dispersal from Mexico to eastern United States in the mid‐Miocene, and early diversification of the EA clade in SW China. Our results also confirmed greater phylogenetic diversity and diversification rate of the EA clade. Species delimitation analysis suggested 17 species in the clade Benthamidia, including all recognized subspecies. By integrating the results of molecular data with morphology, we proposed to retain the subspecies without changing their ranks. Our data suggested increased diversification rate in EA as an intrinsic factor explaining the greater species diversity in the region driven mainly by biogeographic isolation and partially by niche divergence. [ABSTRACT FROM AUTHOR]

Aim: Current distributions of widespread North American (NA) species have been shaped by Pleistocene glacial cycles, latitudinal temperature gradients, sharp longitudinal habitat transitions and the vicariant effects of major mountain and river systems that subdivide the continent. Within these transcontinental species, genetic diversity patterns might not conform to established biogeographic breaks compared to more spatially restricted taxa due to intrinsic differences or spatiotemporal differences. In this study, we highlight the effects of these extrinsic variables on genetic structuring by investigating the phylogeographic history of a widespread generalist squamate found throughout NA. Location: North America. Taxon: Common gartersnake, Thamnophis sirtalis. Methods: We evaluate the effects of major river basins and the forest‐grassland transition into the Interior Plains on genetic structure patterns using phylogenetic, spatially informed population structure and demographic analyses of single nucleotide polymorphism data and address range expansion history with ecological niche modelling using locality and historic climate data. Results: We identify four phylogeographic lineages with varying degrees of connectivity between them. We find discordant population structure patterns between sex‐linked and autosomal loci with respect to the relationship between the central NA lineage relative to coastal lineages. We find support for southeast Pleistocene refugia where recent secondary contact occurred during the Last Glacial Maximum and evidence for both northern and southern refugia in western NA. Main Conclusion: Our results provide strong evidence for a Pliocene origin for T. sirtalis in central‐southeastern NA preceding its rapid expansion across the continent prior to middle Pleistocene climate‐mediated lineage formation. We implicate major riverine networks within the Mississippi watershed in likely repeated westward expansion events across the Interior Plains. Finally, we corroborate prior conclusions that phenotypic differences between subspecies do not reflect shared evolutionary history and note that the degree of separation between inferred lineages warrants further investigation before any taxonomic revisions are proposed. [ABSTRACT FROM AUTHOR]

Aim: Quantifying niche shifts of non‐native species and their interactions with natives is vital in evaluating invasion risk yet remains difficult. Climate filtering and competition with native congeners are two important processes impacting niche changes and yielding contradictory predictions for the coexistence of non‐native and native species. Closely related species representing the Eastern Asia (EA)–Eastern North America (ENA) floristic disjunction provide a powerful yet unexplored system for assessing the relative roles of these two processes. Here, we tested three niche change scenarios (unfilling, expansion and stable) using EA species naturalized in ENA. We aim to answer: (1) which scenario is observed for naturalized species? and (2) how has niche overlap between EA and ENA congeners changed after naturalization? Location: ENA and EA. Time Period: Present. Major Taxa Studied: Angiosperms. Methods: Niches were estimated using both occurrences and predictions generated by ecological niche models. Niche changes of naturalized species and their niche overlap with natives were measured using Schoener's D. Contributions of niche expansion and unfilling on niche changes of naturalized niches were evaluated using hierarchical partitioning and linear regressions. We further measured pairwise phylogenetic distances among EA and ENA congeners and evaluated the association with niche overlap. Results: Unfilling‐dominated postintroduction niche changes of the naturalized species. EA species naturalized in ENA exhibited lower niche overlap with ENA native congeners compared with native range populations in EA. These results remain when considering time since introduction and potential physical dispersal limitations interpreted by projecting suitable niche space between EA and ENA. However, dispersal limitation may contribute to the degree of niche unfilling. Main Conclusions: Using intercontinental disjunct species as a study system, we found that naturalization is shaped jointly by climate filtering and competition with native congeners, providing valuable insights for evaluating invasion risk underlying global floristic exchanges. [ABSTRACT FROM AUTHOR]

Cyprinid herpesvirus‐3 (CyHV‐3) is an important pathogen of common carp (Cyprinus carpio, carp) causing significant economic and ecological impacts worldwide. The recent emergence of CyHV‐3 in the Upper Midwest region of the United States has raised questions related to the disease ecology and host specificity of CyHV‐3 in wild carp populations. To determine the prevalence of CyHV‐3 in wild populations of fishes in Minnesota, we surveyed five lakes in 2019 in which the virus was known to have caused mass mortality events in carp from 2017 to 2018. A total of 28 species (n = 756 total fish) of native fishes and 730 carp were screened for the presence of CyHV‐3 DNA using specific qPCR. None of the native fish tissues tested positive for CyHV‐3 although the prevalence of CyHV‐3 in carp was 10%–50% in the five lakes. A single lake (Lake Elysian) with a 50% DNA detection rate and evidence of ongoing transmission and CyHV‐3‐associated mortality was surveyed again in 2020 from April to September. During this period, none of the tissues from 24 species (n = 607 total fish) tested positive for CyHV‐3 though CyHV‐3 DNA and mRNA (indicating viral replication) was detected in carp tissues during the sampling period. CyHV‐3 DNA was detected most often in brain samples without evidence of replication, potentially indicating that brain tissue is a site for CyHV‐3 latency. Paired qPCR and ELISA testing for Lake Elysian in 2019–2020 identified young carp (especially males) to be the primary group impacted by CyHV‐3‐associated mortality and acute infections, but with no positive detections in juvenile carp. Seroprevalence of carp from Lake Elysian was 57% in 2019, 92% in April of 2020 and 97% in September 2020. These results further corroborate the host specificity of CyHV‐3 to carp in mixed wild populations of fishes in Minnesota and provide additional insights into the ecological niche of CyHV‐3 in shallow lake populations of carp in North America. [ABSTRACT FROM AUTHOR]

Measuring species richness at varying spatial extents can be challenging, especially at large extents where exhaustive species surveys are difficult or impossible. Our work aimed at determining the reliability of species richness estimates from stacked ecological niche models at different spatial extents for taxonomic groups with vastly different environmental dependencies and interactions. To accomplish this, we generated ecological niche models for the species of Cactaceae and Pinaceae that occur within 180 published floras from North America north of Mexico. We overlaid or stacked the resulting species' potential distribution estimates over the bounding boxes representing each of the 180 floras to generate predictions of species richness. In general, our stacked models of Cactaceae and Pinaceae were poor predictors of species richness. The relationships between observed and predicted values improved noticeably with the size of spatial extents. However, the stacked models tended to overpredict the richness of Cactaceae and over‐ and underpredict the richness of Pinaceae. Cactaceae stacked models showed higher sensitivity and lower specificity than those for Pinaceae. We conclude that stacked ecological niche models may be somewhat poor predictors of species richness at smaller spatial extents and should be used with caution for this purpose. Perhaps more importantly, abilities to compensate for their limitations or apply corrections to their reliability may vary with taxonomic groups. [ABSTRACT FROM AUTHOR]

Premise: Researchers often use ecological niche models to predict where species might establish and persist under future or novel climate conditions. However, these predictive methods assume species have stable niches across time and space. Furthermore, ignoring the time of occurrence data can obscure important information about species reproduction and ultimately fitness. Here, we assess compare ecological niche models generated from full‐year averages to seasonal models. Methods: In this study, we generate full‐year and monthly ecological niche models for Capsella bursa‐pastoris in Europe and North America to see if we can detect changes in the seasonal niche of the species after long‐distance dispersal. Results: We find full‐year ecological niche models have low transferability across continents and there are continental differences in the climate conditions that influence the distribution of C. bursa‐pastoris. Monthly models have greater predictive accuracy than full‐year models in cooler seasons, but no monthly models can predict North American summer occurrences very well. Conclusions: The relative predictive ability of European monthly models compared to North American monthly models suggests a change in the seasonal timing between the native range to the non‐native range. These results highlight the utility of ecological niche models at finer temporal scales in predicting species distributions and unmasking subtle patterns of evolution. [ABSTRACT FROM AUTHOR]

The historic western edge of the bison (Bison bison) range and the ecological processes that caused its formation are frequently debated with important implications for bison restoration across North America. We test the hypothesis that a combination of bottom-up habitat suitability and top-down harvest pressure from Indigenous peoples were important processes in forming the western edge of bison distribution. Using 9384 historical journal observations from 1691–1928, we employ MaxEnt ecological niche modelling to identify suitable bison habitat across the Western Cordillera from bottom-up climatic, land cover, and topographic factors. We then use mixed-effect logistic regression to test if bison occurrence in journal records can be in part explained by the abundance of humans, wolves, or grizzly bears, in addition to MaxEnt-derived habitat suitability. We find support for our hypothesis because of the limited suitable habitat in the Rocky Mountains that likely prevented westward bison dispersal from their core habitat, and there was a negative relationship between bison occurrence and human harvest pressure. On this basis, we propose that intensive human harvest from large populations in the Western Cordillera, subsidized by other wildlife, salmon, and vegetation resources, is an underappreciated socioecological process that needs to be restored alongside bison populations. Co-managing bison with Indigenous peoples will also mitigate the adverse effects of overabundant bison populations and maximize the ecological and cultural benefits of bison restoration. [ABSTRACT FROM AUTHOR]

Aim: Species persistence in the face of climate change depends on both ecological and evolutionary factors. Here, we integrate ecological and whole‐genome sequencing data to describe how populations of an alpine specialist, the Brown‐capped Rosy‐Finch (Leucosticte australis) may be impacted by climate change. Location: Southern Rocky Mountains in North America. Methods: We sampled 116 Brown‐capped Rosy‐Finches from 11 sampling locations across the breeding range. Using 429,442 genetic markers from whole‐genome sequencing, we described population genetic structure and identified a subset of 436 genomic variants associated with environmental data. We modelled future climate change impacts on habitat suitability using ecological niche models (ENMs) and impacts on putative local adaptation using gradient forest models (a genetic‐environment association analysis; GEA). We used the metric of niche margin index (NMI) to determine regions of forecasting uncertainty due to climate shifts to novel conditions. Results: Population genetic structure was characterized by weak genetic differentiation, indicating potential ongoing gene flow among populations. Precipitation as snow had high importance for both habitat suitability and changes in genetic variation across the landscape. Comparing ENM and gradient forest models with future climate predicted suitable habitat contracting at high elevations and population allele frequencies across the breeding range needing to shift to keep pace with climate change. NMI revealed large portions of the breeding range shifting to novel climate conditions. Main conclusions: Our study demonstrates that forecasting climate vulnerability from ecological and evolutionary factors reveals insights into population‐level vulnerability to climate change that are obfuscated when either approach is considered independently. For the Brown‐capped Rosy‐Finch, our results suggest that persistence may depend on rapid adaptation to novel climate conditions in a contracted breeding range. Importantly, we demonstrate the need to characterize novel climate conditions that influence uncertainty in forecasting methods. [ABSTRACT FROM AUTHOR]

Simple Summary: The spongy moth (SM) lives in the temperate latitudes of Europe and Asia, as well as in North America (as an invasive species). Caterpillars of the spongy moth feed on tree leaves. They cause significant economic damage, as they lead to the defoliation of trees over vast areas. Studies of the ecology of the spongy moth are necessary to predict possible outbreaks of this insect, as well as to develop effective methods for controlling their numbers. In North America, where the SM is an invasive species, its range is still expanding. Therefore, it is vitally important to build adequate models that will help predict the regions where the SM may appear in the future. The results of our study of Asian SM populations suggest another possible pathway for the SM to spread in the forests of North America. It turns out that the temperature of the rock surface, where the spongy moth lays eggs overwinter, is significantly higher than the temperature of the winter air. Therefore, insects (or their eggs) wintering on rocks can survive colder winter air temperatures than their physiology allows. These results help to reassess the role of the mountain landscape in the spread of insect species. Many insect species overwinter in various rock shelters (cavities and crevices), but the microclimates of rock biotopes remain poorly understood. We investigated the temperature dynamics in rock microhabitats where clusters of egg masses of the wintering spongy moth Lymantria dispar L. (SM) were observed. Our research objective was to find the relation between the ovipositing behaviour of females and the landscape features in different parts of this species' range. Studies of the ecology of the SM are important from a practical point of view, as the moth causes significant economic damage to forests of the Holarctic. We found that the average monthly temperature of rock surfaces in the studied microhabitats was 2–5 °C above the average air temperature. More importantly, the minimum temperatures in these microhabitats were 4–13 °C higher than the minimum air temperature. These results help to reassess the role of the mountain landscape in the spread of insect species. Rock biotopes provided a significant improvement in the conditions for wintering insects. We believe that, when modelling the spread of invasive species (such as the SM), it is necessary to account for the influence of rock biotopes that may facilitate shifts in the northern boundaries of their range. [ABSTRACT FROM AUTHOR]

Competition is a major determinant of where species occur and how species interact. Among carnivorans, interspecific competition is particularly apparent, as many of these species have evolved to be efficient killers. Theoretically, phylogenetically related carnivorans that occupy seasonal habitats, share common resources, and differ in body size by a factor of 2.5–10× should exhibit the most interference competition.Fishers Pekania pennanti and martens Martes americana and Martes caurina are members of the subfamily Guloninae (Mustelidae, Carnivora) that occupy forests throughout northern North America. These taxa occur sympatrically throughout much of their range, utilise similar habitats, and consume similar prey; fishers and martens also differ in body size by a factor 2–5×. Consequently, these two taxa appear to be locked in particularly strong interspecific competition and should attempt to limit competitive overlap.We review the current knowledge of this dyadic interaction in the framework of ecological niches and niche partitioning. In particular, we explore the three critical niche axes of diet, space, and time.We found that, in contrast to the traditional view of them being highly specialised, both martens and fishers are dietary generalists; however, they also appear to be specialists in complexity, at least in space and habitats. Collectively, martens and fishers exhibit high degrees of diet and habitat niche overlap across their ranges, and this overlap is likely to have the greatest fitness consequences for the smaller and subordinate martens. Nevertheless, fine‐scale habitat and prey partitioning, and especially partitioning along snow clines, seem to be the mechanisms by which these two taxa can coexist.We predict that rapid ecological change – especially from increasingly homogenised forests and prey communities, as well as from declining snow cover and snowpack due to climate warming – is likely to destabilise marten–fisher coexistence. As the climate continues to change, fishers and martens are likely to experience distributional and numerical shifts and increased isolation at their southern range boundaries, and vulnerable populations – especially of martens – will be driven to local extirpation. [ABSTRACT FROM AUTHOR]

Aim: While the floras of eastern Asia (EA) and eastern North America (ENA) share numerous genera, they have drastically different species richness. Despite an overall similarity in the quality of their temperate climates, the climate of EA is more spatially heterogeneous than that of ENA. Spatial environmental heterogeneity has been found to play a key role in influencing species richness in some regions. Here, we tested the following hypotheses: (a) EA species will occupy larger climatic niches than their ENA congeners, (b) congeners of EA‐ENA disjunct genera will occupy statistically equivalent climatic niches, and (c) congeners of EA‐ENA disjunct genera will occupy more similar climatic niches than expected by their respective physiographic context. Location: North America and Asia. Time period: Present. Major taxa studied: Seed plants. Methods: Predictions generated by ecological niche models (ENMs) were compared for 88 species across 31 EA‐ENA disjunct genera. ENM predictions were assessed for geographic and ecological breadth. Tests for niche equivalency and similarity were performed for congeneric species pairs to determine if species of disjunct genera have experienced niche conservatism or divergence. Results: EA species tend to occupy greater amounts of climatic niche space than their close relatives in ENA. Over two‐thirds of the conducted niche comparisons show that EA‐ENA congeners either occupy equivalent climatic niche space within these broader climatic regimes or occupy non‐equivalent niches that are as similar as expected given their physiographic contexts. Main conclusions: EA species tend to occupy larger climatic niches, and congeners of EA‐ENA disjunct genera tend to occupy equivalent/similar niche space within their respective distributions, with differences in occupied niches possibly due to their respective physiographic contexts, highlighting how niche‐neutral processes and niche conservatism may affect the distributions of disjunct species. [ABSTRACT FROM AUTHOR]

Aims: In many taxa, the latitudinal span of species' geographic ranges are positively correlated with median latitude (the Rapoport effect). This correlation is frequently explained as adaptation to contemporary climate; however, variability in post‐glacial range expansion among species could also explain this observation. We analyse geographic data for North American salamanders to test the potential causes of Rapoport effects. Location: Temperate North America. Taxon: Salamanders (order Caudata). Methods: We tested for a Rapoport effect by estimating correlations between the latitudinal midpoint and latitudinal range among species. Next, we manipulated species' latitudinal ranges by removing post‐glacial habitat and assessing the impact of species demonstrating post‐glacial range expansion in forming a Rapoport effect. We built ecological niche models for species found south of the Wisconsin Ice Sheet during the Last Glacial Maximum and transferred these models to post‐glacial areas. If dispersal is important in forming a Rapoport effect, then some species may tolerate northern climates but have not expanded northward as a result of variation in geographic access to post‐glacial habitats. We created binary ecological niche models by thresholding using the equal sensitivity and specificity value. Results: We recovered a Rapoport effect that was robust to the null models we tested. Analyses that manipulated ranges and species pools supported a role for variation in post‐glacial range expansion among species, especially for eastern North America. Results from transferring ecological niche models indicated that species have suitable habitat north of their range limit. Main conclusions: Variation in post‐glacial range expansion is important in shaping geographic range size clines among species in areas where climates changed rapidly, though we also found support for the climatic variability hypothesis. Post‐glacial colonization and range expansion likely plays an important role in forming latitudinal biodiversity gradients in northern taxa. While ecophysiology and biotic interactions have been emphasized as important contributors to diversity gradients, our study indicates that post‐glacial colonization also plays a key role in forming latitudinal gradients. [ABSTRACT FROM AUTHOR]

Polyploidy results from whole-genome duplication and is a unique form of heritable variation with pronounced evolutionary implications. Different ploidy levels, or cytotypes, can exist within a single species, and such systems provide an opportunity to assess how ploidy variation alters phenotypic novelty, adaptability, and fitness, which can, in turn, drive the development of unique ecological niches that promote the coexistence of multiple cytotypes. Switchgrass, Panicum virgatum, is a widespread, perennial C4 grass in North America with multiple naturally occurring cytotypes, primarily tetraploids (4×) and octoploids (8×). Using a combination of genomic, quantitative genetic, landscape, and niche modeling approaches, we detect divergent levels of genetic admixture, evidence of niche differentiation, and differential environmental sensitivity between switchgrass cytotypes. Taken together, these findings support a generalist (8×)-specialist (4×) trade-off. Our results indicate that the 8× represent a unique combination of genetic variation that has allowed the expansion of switchgrass' ecological niche and thus putatively represents a valuable breeding resource. [ABSTRACT FROM AUTHOR]

In a landmark comparative phylogeographic study, "Comparative phylogeography of unglaciated eastern North America," Soltis et al. (Molecular Ecology, 2006, 15, 4261) identified geographic discontinuities in genetic variation shared across taxa occupying unglaciated eastern North America and proposed several common biogeographical discontinuities related to past climate fluctuations and geographic barriers. Since 2006, researchers have published many phylogeographical studies and achieved many advances in genotyping and analytical techniques; however, it is unknown how this work has changed our understanding of the factors shaping the phylogeography of eastern North American taxa. We analyzed 184 phylogeographical studies of eastern North American taxa published between 2007 and 2019 to evaluate: (1) the taxonomic focus of studies and whether a previously detected taxonomic bias towards studies focused on vertebrates has changed over time, (2) the extent to which studies have adopted genotyping technologies that improve the resolution of genetic groups (i.e., NGS DNA sequencing) and analytical approaches that facilitate hypothesis‐testing (i.e., divergence time estimation and niche modeling), and (3) whether new studies support the hypothesized biogeographic discontinuities proposed by Soltis et al. (Molecular Ecology, 2006, 15, 4261) or instead support new, previously undetected discontinuities. We observed little change in taxonomic focus over time, with studies still biased toward vertebrates. Although many technological and analytical advances became available during the period, uptake was slow and they were employed in only a small proportion of studies. We found variable support for previously identified discontinuities and identified one new recurrent discontinuity. However, the limited resolution and taxonomic breadth of many studies hindered our ability to clarify the most important climatological or geographical factors affecting taxa in the region. Broadening the taxonomic focus to include more non‐vertebrate taxa, employing technologies that improve genetic resolution, and using analytical approaches that improve hypothesis testing are necessary to strengthen our inference of the forces shaping the phylogeography of eastern North America. [ABSTRACT FROM AUTHOR]

Aim: The plant species sharing ancestors now disjunctly distributed in eastern Asia (EAS) and eastern North America (ENA) have long been a biogeographic puzzle. Species within the EAS–ENA disjunct genera are presumed to exhibit niche conservatism, the tendency of closely related species to be more ecologically similar, reflecting lineages' common evolutionary history. However, the hypothesis has not been well examined at the species level. Location: EAS and ENA. Time period: Current. Major taxa studied: Species within the EAS–ENA disjunct genera. Methods: We compiled data on climate, species occurrence, growth form, and phylogeny to examine niche conservatism. We first built a phylogenetic tree to select intercontinental congeneric pairwise species and obtained their divergence times. We then quantified the observed niche overlaps with Schoener's D, which has a 0–1 range, based on species occurrence and climate of species' native ranges. To obtain projected distributions, each species' niche was projected to the non‐native region using ensemble ecological niche models. Projected‐related niche overlaps were then calculated using projected distributions and the corresponding climatic conditions. Results: Average observed niche overlaps of congeneric pairwise species were relatively small:.124,.211 and.109 for all, herbaceous and woody species, respectively. Both observed and projected‐related niche overlaps had significant negative relationships with divergence times of intercontinental congeneric pairwise species, with niche overlap for herbaceous species being higher than that for woody plants when controlling for divergence times. Main conclusions: We conclude that the significant negative relationships between niche overlap and divergence times of congeneric pairwise species confirm niche conservatism among species of EAS–ENA disjunct plants and that the extent of niche conservatism is slightly different for herbaceous and woody plants. These findings suggest the potential role of allopatric speciation in EAS, and could help to understand the evolutionary history and the Asian‐bias diversity pattern of the EAS–ENA disjunct plants. [ABSTRACT FROM AUTHOR]

Aim: Abiotic, biotic and dispersal factors interact to shape species distributions. At broad geographic extents, abiotic factors are thought to exert the greatest influence on the distribution, while biotic and dispersal factors strongly influence the distribution regionally and locally. We test whether reproductive traits relating to biotic and dispersal factors explain differences between estimated potential and occupied geographic distributions for 21 species of Trillium. Location: Eastern North America. Methods: Fundamental niches and associated predicted suitable distributions were estimated using climate‐calibrated ecological niche models. We defined occupied distributions as the intersection between known ranges and predicted suitable areas (PSAs). Proportional occupancy of the predicted suitable distribution (PO) was calculated by dividing the area of the occupied distribution by the PSA. We related reproductive traits (ovule number, seed set, number of seeds/plant, seed mass, adult biomass, flower type: sessile/pedicellate) to PO using beta regression models. AICc was used to assess model fit. Results: There was considerable variation in PO across species (1.1%–96%, mean = 51%). Eighty‐five percent of species with PO < 60% were sessile; 88% of species with PO > 60% were pedicellate. The best‐fit beta regression (pseudo R2 =.70) yielded significantly lower PO for sessile‐flowered species; ovule number and seed mass were also significant predictors of PO. Main conclusions: Variation in PO among study species can be explained by flower type, ovule number and seed mass—biotic traits related to dispersal ability. We posit that variation in dispersal potential stemming from primary and long‐distance dispersers is related to occupancy of the predicted suitable distribution in Trillium. We exemplify a scenario in which life history traits explain why some species are range‐restricted when their close relatives are widespread. Our methodology constitutes a powerful comparative framework that can be applied to diverse biological systems to inform conservation of rare species. [ABSTRACT FROM AUTHOR]

The introduction of alien species is one of the main problems in conservation. Many successful invaders cause severe economic and ecological damage. Such is the case of Leptoglossus occidentalis, a phytophagous true bug native to North America, which has become a pest in Europe, Asia, Africa and South America. Within the genus, another species whose distributional range is expanding toward the east of North America is Leptoglossus clypealis. As climate determines the successful establishment of insects, the identification of climatically suitable areas for invasive species based on ecological niche models (ENMs) offers an excellent opportunity for preventing invasions. In this study, ENMs were built for both species and their native climatic niches were compared. Their niche breath was also measured. The climatic niches of both species are identical and the niche breadth of L. clypealis is broader than that of L. occidentalis. In view of the great ecological resemblance between these two species, we believe that L. clypealis could became a major pest thus it should be carefully monitored. The results of the present worldwide ENMs showed numerous regions with suitable conditions for the establishment of both species. The future ENMs exhibited a retraction in the suitable areas in North America, Europe and Asia. [ABSTRACT FROM AUTHOR]

Biological invasions and climate change are important drivers of biodiversity loss. In freshwater ecosystems, golden and zebra mussels are two highly aggressive invasive species that have caused ecological and economic damages in South and North America, respectively. Here, we used ecological niche models (ENMs) to investigate the invasive potential of golden and zebra mussels in present and future scenarios of global warming in the New World. We found two main patterns in the distribution of suitable areas for golden and zebra mussels. First, the distribution of potentially suitable areas, both in present and future scenarios, is different between mussel species: zebra mussel has areas that are more suitable in temperate regions, while suitable areas for golden mussel are concentrated in tropical and subtropical regions. Second, suitable habitats for golden mussel will increase more in future global warming scenarios compared to suitable habitats for zebra mussel. Indeed, there are experimental indications that zebra mussel has a lower tolerance to high temperatures compared to golden mussel, which is in agreement with our findings. We recommend that the future monitoring of both golden and zebra mussels in the New World should consider areas of highest thermic suitability for current and future scenarios. [ABSTRACT FROM AUTHOR]

In ecological niche theory, diet is a trait frequently used to place species along a continuum from specialists to generalists. A multidimensional approach to investigating species' niches has been developed to incorporate nutrition. We apply the concepts of multidimensional nutritional niche theory to the dietary patterns of a widespread, large herbivore, the American bison Bison bison, at various levels of its nutritional niche.Specifically, we sought to estimate dietary niches for female bison at the levels of the forage items they consume and the macronutrients they acquire from those forage items. We assessed how these dietary niches changed seasonally and explored physical and climatic mechanisms that contribute to observed differences in the dietary niches. We also examined dietary differences between the two bison subspecies: wood bison Bison bison athabascae and plains bison Bison bison bison.We compiled data for 16 bison subpopulations using 26 peer‐reviewed publications, government reports, conference proceedings, and graduate theses that described the dietary composition of female bison for analysis of dietary niches.We found that the diets of female bison were, as expected, dominated by graminoids throughout the year, but during the growing season (spring and summer), dietary niches had greater breadth. Their diets were relatively high in carbohydrates, but percentages of dietary lipid and protein increased during the growing season. Further, we found significant increases in consumption of browse items, lipids, and proteins with increasing latitude (†N), and differences between American bison subspecies.Our study provides insight into the fundamental macronutrient niche of the American bison and also provides a framework for the nutritional targets of bison. We show that bison are able to adapt to availability of local forage and that they may consume different items in different proportions in order to regulate nutritional composition of their diet. [ABSTRACT FROM AUTHOR]

Stable isotopes of mammoths and mastodons have the potential to illuminate ecological changes in late Pleistocene landscapes and megafaunal populations as these species approached extinction. The ecological factors at play in this extinction remain unresolved, but isotopes of bone collagen (δ13C, δ15N) and tooth enamel (δ13C, δ18O, 87Sr/86Sr) from midwestern North America are leveraged to examine ecological and behavioral changes that occurred during the last interglacial-glacial cycle. Both species had significant C3 contributions to their diets and experienced increasing levels of niche overlap as they approached extinction. A subset of mastodons after the last glacial maximum exhibit low δ15N values that may represent expansion into a novel ecological niche, perhaps densely occupied by other herbivores. Stable isotopes from serial and microsampled enamel show increasing seasonality and decreasing temperatures as mammoths transitioned from Marine Isotope Stage (MIS) 5e to glacial conditions (MIS 4, MIS 3, MIS 2). Isotopic variability in enamel suggests mobility patterns and life histories have potentially large impacts on the interpretation of their stable isotope ecology. This study further refines the ecology of midwestern mammoths and mastodons demonstrating increasing seasonality and niche overlap as they responded to landscape changes in the final millennia before extinction. [ABSTRACT FROM AUTHOR]

Species distribution estimates are often used to understand the niche of a species; however, these are often based solely on climatic predictors. When the influences of biotic factors are ignored, erroneous inferences about range and niche may be made. We aimed to integrate climate data with a unique set of available land cover and land use data for the six cold‐adapted amphibians of North America (Ambystoma macrodactylum, Anaxyrus hemiophrys, Anaxyrus boreas, Pseudacris maculata, Rana sylvatica, Rana luteiventris) to determine the relative importance of climate and non‐climate drivers through the use of ecological niche models for present‐day range estimates. We compared climate‐only, land use‐only, and combination models of climate and land use, derived from two different model selection techniques, to determine which was most likely to drive current distributions of cold‐adapted amphibian species. Land use layers included land cover type, human population, vegetation type, ecoregion, and the overall human footprint. The most supported models included both climate and land use, with climate and human footprint variables having the highest permutation importance and percent contribution. Models that incorporated climate and land use data performed best as measured with AIC and AUC, although qualitatively most underestimated the northern range edge, implying potential sampling bias or locations of reduced habitat quality for these species in the northern area of the ranges. There were small differences in overall combination models dependent on the method of model selection. The overall effect sizes of landscape factors within the combination models were small except for one landscape feature: human footprint, which incorporated multiple aspects of anthropogenic change on the landscape, including human population density, travel access, and agricultural impact. This aspect of the landscape was just as important as climate, and counter to what we expected, the association was mostly positive, with a negative response only occurring at very high levels. This highlights the importance of moving beyond climate only species range estimates as land cover, specifically human impact, may be driving the patterns of species' ranges. [ABSTRACT FROM AUTHOR]

The conservation of aquatic species with complex life histories requires the protection of habitat for each life stage. Coastal cutthroat trout (Oncorhynchus clarkii clarkii) exhibit both mobile and sessile stages and are of conservation concern in north‐western North America. Models that predict how habitat changes with flow can inform water management for the species but rely on habitat descriptors that change with flow and are not suited to sessile life stages.Spawning and incubation habitat availability and use for coastal cutthroat trout were assessed in mesohabitats and microhabitats. Primary channel units were tallied, dimensions were measured, redds were counted, and redd locations within channel units were measured.Primary channel units were subdivided based on relative residual depth (RRD, bed elevation in relation to maximum pool depth) and hydraulic control (HC, the lowest point on the highest ridge across the riffle that controls the water surface elevation in the upstream pool). Habitat suitability was calculated for depth (D), velocity (V), Froude number (Fr), substrate (S), RRD, and channel units.Redds in riffles and pools were close to hydraulic controls; suitability decreased upstream in pools and downstream in riffles. Maximum suitability values were: 21–24 cm for D, 0.05–0.10 for RRD, 61–64 cm s−1 for V, >0.80 for Fr, and 1.3 to <3.8 cm for S. Channel units, RRDs, and microhabitat better identified spawning habitat than microhabitat alone.The results suggest that RRD and stage of zero flow are good indicators of habitat suitability for spawning through fry emergence and could be adapted for use with other species. This work generates criteria for delineating flow‐independent channel units that can be used to set more protective instream flows, prioritize the acquisition of instream water or conservation easements to protect critical habitat, and inform restoration projects to optimize habitat availability. [ABSTRACT FROM AUTHOR]

Globally, savanna trees experience bottlenecks to recruitment. Likelihoods are low that juveniles, especially of nonclonal, reseeder species, will survive and reach sizes that survive recurrent fires. We hypothesized if ground layer vegetation within savannas contained patches with reduced fire effects, likelihoods of juvenile trees surviving fires would be increased. We refined our general hypothesis based on a field study in an old-growth southeastern pine savanna of North America, in which longleaf pine (Pinus palustris Mill.) is the most abundant tree. We hypothesized that recruitment of pines into the fire-resistant 'grass stage' may be more likely in three ground layer microhabitats (inside crowns of fallen pines, around pine tree stumps, and inside patches of oak/hardwood stems) than in surrounding groundcover located away from overstory pines. We measured the composition and abundance of ground layer vegetation and censused juvenile grass stages (< 1.5 m height) of longleaf pine in plots in replicated patches of these three microhabitats and in the surrounding ground layer matrix, all located away from large trees. Ground layer vegetation was less abundant inside than outside the three microhabitats and abundances of grasses and shrubs differed among microhabitats. A zero-inflated Poisson model indicated that occurrence of grass stage longleaf pines was >5 times more likely inside the three microhabitats than in the surrounding ground layer matrix. Recruitment was also more likely in pine than oak/hardwood microhabitats. We propose that altered microhabitats, especially those generated by death of large longleaf pines, likely facilitate recruitment into populations of this reseeding savanna tree. [ABSTRACT FROM AUTHOR]

Climate variability is the most important force affecting distributional range dynamics of common and widespread species with important impacts on biogeographic patterns. This study integrates phylogeography with distributional analyses to understand the demographic history and range dynamics of a widespread bird species, the Ruffed Grouse (Bonasa umbellus), under several climate change scenarios. For this, I used an ecological niche modeling approach, together with Bayesian based phylogeographic analysis and landscape genetics, to develop robust inferences regarding this species' demographic history and range dynamics. The model's predictions were mostly congruent with the present distribution of the Ruffed Grouse. However, under the Last Glacial Maximum bioclimatic conditions, the model predicted a substantially narrower distribution than the present. The predictions for the Last Glacial Maximum also showed three allopatric refugia in south-eastern and west-coast North America, and a cryptic refugium in Alaska. The prediction for the Last Interglacial showed two separate distributions to the west and east of the Rocky Mountains. In addition, the predictions for 2050 and 2070 indicated that the Ruffed Grouse will most likely show slight range shifts to the north and will become more widely distributed than in the past or present. At present, effective population connectivity throughout North America was weakly positively correlated with Fst values. That is, the species' distribution range showed a weak isolation-by-resistance pattern. The extended Bayesian Skyline Plot analysis, which provided good resolution of the effective population size changes over the Ruffed Grouse's history, was mostly congruent with ecological niche modelling predictions for this species. This study offers the first investigation of the late-Quaternary history of the Ruffed Grouse based on ecological niche modelling and Bayesian based demographic analysis. The species' present genetic structure is significantly affected by past climate changes, particularly during the last 130 kybp. That is, this study offers valuable evidence of the 'expansion–contraction' model of North America's Pleistocene biogeography. [ABSTRACT FROM AUTHOR]

Springs ecosystems are globally abundant, geomorphologically diverse, and bio‐culturally productive, but are highly imperiled by anthropogenic activities. More than a century of scientific discussion about the wide array of ecohydrological factors influencing springs has been informative, but has yielded little agreement on their classification. This lack of agreement has contributed to the global neglect and degradation of springs ecosystems by the public, scientific, and management communities. Here we review the historical literature on springs classification variables, concluding that site‐specific source geomorphology remains the most diagnostic approach. We present a conceptual springs ecosystem model that clarifies the central role of geomorphology in springs ecosystem development, function, and typology. We present an illustrated dichotomous key to terrestrial (non‐marine) springs ecosystem types and subtypes, and describe those types. We identify representative reference sites, although data limitations presently preclude selection of continentally or globally representative reference springs of each type. We tested the classification key using data from 244 randomly selected springs of 13 types that were inventoried in western North America. The dichotomous key correctly identified springs type in 87.5% of the cases, with discrepancies primarily due to differentiation of primary vs. secondary typology, and insufficient inventory team training. Using that information, we identified sources of confusion and clarified the key. Among the types that required more detailed explanation were hypocrenes, springs in which groundwater is expressed through phreatophytic vegetation. Overall, springs biodiversity and ecosystem complexity are due, in part, to the co‐occurrence of multiple intra‐springs microhabitats. We describe microhabitats that are commonly associated with different springs types, reporting at least 13 microhabitats, each of which can support discrete biotic assemblages. Interdisciplinary agreement on basic classification is needed to enhance scientific understanding and stewardship of springs ecosystems, the loss and degradation of which constitute a global conservation crisis. [ABSTRACT FROM AUTHOR]

Aim: Temperature plays an important role in determining distributions of ectothermic species, yet many ectotherms have wide distributions across diverse environmental conditions. Our goal was to model regional differences in annual and seasonal activity patterns among populations of Phrynosoma platyrhinos across its climatically diverse distribution. We hypothesize that microhabitat availability and behavioural thermoregulation will not mitigate large‐scale climatic differences across the species' distribution, resulting in alteration of activity patterns of populations. Location: Western deserts of North America. Taxon: Desert Horned Lizard (Phrynosoma platyrhinos). Methods: We used biophysical models to (a) model microhabitat conditions at 31 localities across the species' range, (b) model body temperature profiles of a theoretical lizard using microhabitat conditions, physiological and thermal parameters and the ability of lizards to thermoregulate behaviourally and (c) predict year‐round activity patterns of P. platyrhinos across its range, quantified as the percentage of time permissible for basking or foraging. Results: The models identified that different populations of P. platyrhinos experience differences in predicted activity patterns, both daily and seasonally, with up to 67% more time suitable for foraging in the southern than northern deserts. Southern populations have more potential for year‐round activity, but predicted activity is reduced during hot summer months. The northern populations have less time for activity overall because of low temperatures in the spring and fall. However, summer‐predicted activity is greater than in the southern regions. Main conclusions: We detected pronounced regional differences in the times available to P. platyrhinos for activity. We conclude that behaviour and microclimate conditions are not able to fully mitigate the effects of large‐scale thermal variation, and that lizards compensate for climatic variation by shifting their daily and seasonal predicted activity patterns. These differences can be tied to inter‐population variation in life history traits. [ABSTRACT FROM AUTHOR]

Aim: We tested whether we could detect geographical shifts in modelled‐suitable habitat. We aim to enhance phylogenetic niche models of past suitable habitats for Sceloporus lineages by integrating modern and fossil occurrences with ecological and phylogenetic comparative modelling methods. Specifically, we hypothesized that our integrated approach is sensitive enough to detect geographical shifts in suitable habitat between lineages and through evolutionary time. Location: North America. Taxon: Sceloporus lizards. Methods: We used extant and fossil occurrence data, general circulation models of palaeoclimate, climate envelope modelling and phylogenetic comparative methods to reconstruct past suitable climates for Sceloporus lizards over the last 20 million years, and then visualized the geographical locations of individual lineages using multivariate environmental similarity surfaces (MESS) maps. Results: We were able to reconstruct ancestral suitable climate for Sceloporus lineages with sufficient resolution to identify shifts in geographical location between lineages. We found that large shifts in climate regimes drove the expansion and contraction of suitable habitat through time. We found a positive association between tectonic events, like mountain uplift, and lineage diversification in the Sceloporus clade. Mountain uplift also facilitated the emergence of open grassland habitat, which excluded many Sceloporus species. Main conclusions: Our approach was sensitive enough to detect differences in geographical location of suitable habitat across lineages and through evolutionary time. Doing so is a critical first step to tracking the evolutionary ecology of individual taxa over long periods of evolutionary time, and to inferring which species co‐existed in which locations. Such inferences would allow for more precise predictions of current and future ecological needs for conservation efforts, and to inform efforts to mitigate climate change. [ABSTRACT FROM AUTHOR]

Nyssa (Nyssaceae, Cornales) represents a classical example of the well‐known eastern Asian–eastern North American floristic disjunction. The genus consists of three species in eastern Asia, four species in eastern North America, and one species in Central America. Species of the genus are ecologically important trees in eastern North American and eastern Asian forests. The distribution of living species and a rich fossil record of the genus make it an excellent model for understanding the origin and evolution of the eastern Asian–eastern North American floristic disjunction. However, despite the small number of species, relationships within the genus have remained unclear and have not been elucidated using a molecular approach. Here, we integrate data from 48 nuclear genes, fossils, morphology, and ecological niche to resolve species relationships, elucidate its biogeographical history, and investigate the evolution of morphology and ecological niches, aiming at a better understanding of the well‐known EA–ENA floristic disjunction. Results showed that the Central American (CAM) Nyssa talamancana was sister to the remaining species, which were divided among three, rapidly diversified subclades. Estimated divergence times and biogeographical history suggested that Nyssa had an ancestral range in Eurasia and western North America in the late Paleocene. The rapid diversification occurred in the early Eocene, followed by multiple dispersals between and within the Erasian and North American continents. The genus experienced two major episodes of extinction in the early Oligocene and end of Neogene, respectively. The Central American N. talamancana represents a relic lineage of the boreotropical flora in the Paleocene/Eocene boundary that once diversified in western North America. The results supported the importance of both the North Atlantic land bridge and the Bering land bridge (BLB) for the Paleogene dispersals of Nyssa and the Neogene dispersals, respectively, as well as the role of Central America as refugia of the Paleogene flora. The total‐evidence‐based dated phylogeny suggested that the pattern of macroevolution of Nyssa coincided with paleoclimatic changes. We found a number of evolutionary changes in morphology (including wood anatomy and leaf traits) and ecological niches (precipitation and temperature) between the EA–ENA disjunct, supporting the ecological selection driving trait evolutions after geographic isolation. We also demonstrated challenges in phylogenomic studies of lineages with rapid diversification histories. The concatenation of gene data can lead to inference of strongly supported relationships incongruent with the species tree. However, conflicts in gene genealogies did not seem to impose a strong effect on divergence time dating in our case. Furthermore, we demonstrated that rapid diversification events may not be recovered in the divergence time dating analysis using BEAST if critical fossil constraints of the relevant nodes are not available. Our study provides an example of complex bidirectional exchanges of plants between Eurasia and North America in the Paleogene, but "out of Asia" migrations in the Neogene, to explain the present disjunct distribution of Nyssa in EA and ENA. [ABSTRACT FROM AUTHOR]

The eastern Asian (EA)–eastern North American (ENA) floristic disjunction represents a major pattern of phytogeography of the Northern Hemisphere. Despite 20 years of studies dedicated to identification of taxa that display this disjunct pattern, its origin and evolution remain an open question, especially regarding post‐isolation evolution. The blue‐ or white‐fruited dogwoods (BW) are the most species‐rich among the four major clades of Cornus L., consisting of ~35 species divided into three subgenera (subg. Yinquania, subg. Mesomora, and subg. Kraniopsis). The BW group provides an excellent example of the EA–ENA floristic disjunction for biogeographic study due to its diversity distribution centered in eastern Asia and eastern North America, yet its species relationships and delineation have remained poorly understood. In this study, we combined genome‐wide markers from RAD‐seq, morphology, fossils, and climate data to understand species relationships, biogeographic history, and ecological niche and morphological evolution. Our phylogenomic analyses with RAxML and MrBayes recovered a strongly supported and well‐resolved phylogeny of the BW group with three intercontinental disjunct clades in EA and ENA or Eurasia and North America, of which two are newly identified within subg. Kraniopsis. These analyses also recovered a potential new species but failed to resolve relationships within the C. hemsleyi–C. schindleri complex. In an effort to develop an approach to reduce computation time, analysis of different nodal age settings in treePL suggests setting a node's minimum age constraint to the lower bound of a fossil's age range to obtain similar ages to that of BEAST. Divergence time analyses with BEAST and treePL dated the BW stem back to the very Late Cretaceous and the divergence of the three subgenera in the Paleogene. By integrating fossil ages and morphology, a total evidence‐based dating approach was used in conjunction with time‐slice probabilities of dispersal under a DEC model to resolve ancestral ranges of each disjunct in the Miocene: Eurasia and ENA (disjunct 1), EA and western North America (disjunct 2), and EA (disjunct 3). The dated biogeographic history supports dispersal via the North Atlantic Land Bridge in the late Paleogene in disjunct 1 and dispersal via the Bering Land Bridge in the Miocene for disjuncts 2 and 3. Character mapping with a stochastic model in phytools and comparison of ecological niche, morphospace, and rate of evolution indicated differential divergence patterns in morphology, ecological niche, and molecules between disjunct sisters. Although morphological stasis was observed in most of the characters, evolutionary changes in growth habit and some features of leaf, flower, and fruit morphology occurred in one or both sister clades. A significant differentiation of ecological habitats in temperature, precipitation, and elevation between disjunct sisters was observed, suggesting a role of niche divergence in morphological evolution post‐isolation. The patterns of evolutionary rate between morphology and molecules varied among disjunct clades and were not always congruent between morphology and molecules, suggesting cases of non‐neutral morphological evolution driven by ecological selection. Our phylogenetic evidence and comparisons of evolutionary rate among disjunct lineages lend new insights into the formation of the diversity anomaly between EA and ENA, with particular support of an early diversification in EA. These findings, in conjunction with previous studies, again suggest that the EA–ENA disjunct floras are an assembly of lineages descended from the Mesophytic Forests that evolved from the early Paleogene "boreotropical flora" through varied evolutionary pathways across lineages. [ABSTRACT FROM AUTHOR]

Diapensiaceae (Ericales) are a small family of about 15 species. Within this clade, two species are broadly distributed throughout the Northern Hemisphere, whereas the remaining species have a disjunct distribution between eastern North America and eastern Asia. To address patterns and processes of diversification in Diapensiaceae, we conducted biogeographic analyses and inferred shifts in the ecological niche across the phylogeny of the clade. Although Diapensiaceae have been the focus of multiple phylogenetic and biogeographic studies, previous studies have been taxonomically limited. This study has greatly improved the phylogenetic underpinning for Diapensiaceae with the most inclusive taxonomic sampling thus far, employing both nuclear and plastid gene sequence data for at least one sample per species in the family. Our estimates indicate that genera of Diapensiaceae variously diverged in the Eocene, Oligocene, and early to mid‐Miocene. The biogeographic analysis suggests that the probable ancestor of the Diapensiaceae crown clade originated in the Nearctic, with vicariance events contributing to the current distribution of the disjunct taxa. Ecological niche, when considered in a phylogenetic context, was observed to be clustered on the basis of biogeographic realm. In general, a greater ecological overlap was found at younger nodes and a greater niche divergence was found among distantly related species. Diversification in Diapensiaceae appears to have been shaped by both large‐scale biogeographic factors, such as vicariance, and divergence in an ecological niche among closely related species. [ABSTRACT FROM AUTHOR]

The round goby (Neogobius melanostomus) is among the fastest‐spreading introduced aquatic species in North America and is radiating inland from the Great Lakes into freshwater ecosystems across the landscape. Predicting and managing the impacts of round gobies requires information on the factors influencing their distribution in habitats along the invasion front, yet this information is not available for many recently invaded ecosystems. We evaluated the seasonal habitat use and biomass of round gobies in an inland temperate lake to define the spatiotemporal scope of biological interactions at the leading edge of the round goby invasion.Using novel statistical approaches, we combined hierarchical models that control for imperfect species detection with flexible smooth terms to describe non‐linear relationships between round goby abundance and environmental gradients. Subsequently, we generated accurate detection‐corrected estimates of the standing stock biomass of round gobies.Our results show seasonally differentiated habitat niches, where suitable round goby habitat in summer months is restricted to shallow depths (<18.4 m) with a mixture of vegetative and mussel cover. We found high round goby biomass of 122 kg/ha in occupied habitats during the summer, with a total lake‐wide biomass of 766,000 kg. In winter, round gobies migrate to deep offshore habitats and disperse, dramatically altering their scope for biological interactions with resident aquatic species across summer and winter seasons.The results of this study indicate that the scope of biological interactions in inland lakes may be seasonally variable, with potential for high round goby biomass in shallow lakes or at the periphery of deep lakes in the summer months. Such shallow‐water habitats may therefore present higher risk of ecological impacts from round gobies in invaded lentic ecosystems. As round gobies expand inland, consideration of seasonal habitat use will be an important factor in predicting the impacts of this pervasive invader. [ABSTRACT FROM AUTHOR]

The coastal rock pool mosquito, Aedes (Tanakius) togoi (Theobald) (Diptera: Culicidae), is found in coastal east Asia in climates ranging from subtropical to subarctic. However, a disjunct population in the Pacific Northwest of North America has an ambiguous heritage. Two potential models explain the presence of Ae. togoi in North America: ancient Beringian dispersal or modern anthropogenic introduction. Genetic studies have thus far proved inconclusive. Here we described the putative ancient distribution of Ae. togoi habitat in east Asia and examined the climatic feasibility of a Beringian introduction into North America using modern distribution records and ecological niche modeling of bioclimatic data from the last interglacial period (~120,000 BP), the last glacial maximum (~21,000 BP), and the mid-Holocene (~6000 BP). Our results suggest that suitable climatic conditions existed for Ae. togoi to arrive in North America through natural dispersal as well as to persist there until present times. Furthermore, we find that ancient distributions of suitable Ae. togoi habitat in east Asia may explain the genetic relationships between Ae. togoi populations identified in other studies. These findings indicate the utility of ecological niche modeling as a complementary tool for studying insect phylogeography. [ABSTRACT FROM AUTHOR]

Aim: Assessing the relevance of niche evolution in the diversification patterns and geographical distribution of species driven by climate remains a challenge. We apply an integrative approach to evaluate the role of the environment on the phylogeography of bear species, incorporating fossil data to characterize the changes in the ecological niche through time. We evaluate our approach with the four extant species of bears within Ursus, the best represented taxon in the fossil record of the family Ursidae. Location: Eurasia and North America. Taxa: Asian black bear, Ursus thibetanus; American black bear, U. americanus; Brown bear, U. arctos; and Polar bear, U. maritimus. Methods: We built a genetic and a geographical database from all published mitochondrial DNA sequences and of species occurrence records. We defined the most significant climatic variables based on each species ecological realm using correlation matrices, and characterized the ecological niches and existing environmental conditions with ellipsoid models. We inferred their current and Last Glacial Maximum (LGM) ecological niche modellings (ENMs) and compared the results with the fossil record. We estimated the times of divergence (d‐loop sequences) of lineages and applied a phyloclimatespace approach to discern the phylogeographical patterns along each species' ecological space. Results: Ecological niche modelling showed wider niches for U. thibetanus and U. americanus encompassing higher temperature and precipitation, while U. arctos and U. maritimus showed an opposite pattern. LGM models were consistent with the fossil record, predicting 55%–89% of the fossil occurrences (within their suitability areas). The phyloclimatespace revealed different degrees of environmental signal in the lineages' phylogeographical patterns and ecological trajectories associated with LGM climatic conditions. Results indicated habitat tracking and ecological expansion since the LGM towards more extreme precipitation and temperature conditions for three species, except U. maritimus that showed ecological niche reduction. Main Conclusions: Incorporating fossil information from the LGM improved our characterization and interpretation of ecological models, by enabling definition of the limits of the climatic conditions explored by the species in the past. Our approach also provided insights about the existing set of environmental conditions shaping the ecological niche divergence of Ursus bears. We were able to depict key features of the lineages' evolutionary history, ecology and distribution, revealing the dynamics of niche occupation and the environmental signal on the phylogeographical patterns of Ursus. [ABSTRACT FROM AUTHOR]

Copyright of Forestry Chronicle is the property of Canadian Institute of Forestry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Cladrastis clade is an early‐diverged lineage within the subfamily Papilionoideae of Leguminosae. Several taxonomic uncertainties limit a robust understanding of its taxonomy: (1) Should the genus Platyosprion be resurrected? (2) How should Cladrastis be delimited to maintain the generic monophyly? (3) Is Styphnolobium best classified into two or three sections? We assessed specific/sectional/generic boundaries within this clade by integrating evidence from phylogenetic analyses, morphology, and multivariate ecological methods. With an extensive sampling of the clade, we reconstructed the phylogenies using nrDNA (ITS) and plastid DNA regions (matK, psbA‐trnH, trnL‐F). Based on environmental data for 841 occurrences, clusters of species were sought according to their environmental preferences with the principal component analysis (PCA), and explicit hypotheses on species/sectional boundaries were tested using ecological niche modeling (ENM). A new tribe, Cladrastideae, is established based on the Cladrastis clade with four monophyletic groups: the Cladrastis platycarpa complex, Cladrastis s.str., Pickeringia and Styphnolobium. The C. platycarpa complex constitutes the resurrected genus Platyosprion. The putative species C. chingii, C. parvifolia, C. scandens and C. yungchunii are suggested to be treated as synonyms of Platyosprion platycarpum. Cladrastis is recircumscribed as equal to Cladrastis s.str., with three species from eastern Asia, and one species, C. kentukea, from eastern North America. Styphnolobium is herein classified into three sections: St. sect. Oresbios, St. sect. Styphnolobium and a new section, St. sect. Affine. [ABSTRACT FROM AUTHOR]

This paper describes and interprets the results of multiple analyses conducted on human paleofeces from Turkey Pen Ruin, an early Ancestral Pueblo farming site in Cedar Mesa, Utah. Analyses of pollen and macroscopic contents were performed on 44 specimens; DNA testing for several faunal and botanical dietary constituents was also conducted on select samples (n = 20) using targeted PCR analysis. These data were used to assess what foods supplemented the predominant dietary staple—maize (Zea mays). Resources were evaluated based on caloric efficiency and nutritional value to gain insight into what motivated these late Basketmaker II period (ca. AD 1-400) farmers to continuously rely so heavily on corn, in lieu of incorporating a higher proportion of foraged resources into their diet. This project confirms a very high level of maize reliance (likely around 80% of the diet) as established by earlier studies. However, these results also show common inclusion of wild resources that are much less calorically efficient than the type of maize farming practiced here, including weedy plants commonly associated with agricultural fields. This suggests early farmers on Cedar Mesa were pushed by low environmental productivity to rely on farming, and to include low-ranked wild resources to calorically and nutritionally augment their maize-based diet. These findings also indicate that farmers were harvesting much more than corn from their fields, and that the productivity of the anthropogenic ecological niche created by farming activities may have influenced supplemental foraging choices, as well as the degree of labor dedicated to fields. [ABSTRACT FROM AUTHOR]

What makes a species able to colonize novel environments? This question is key to understand the dynamics of adaptive radiations and ecological niche shifts, but the mechanisms that underlie expansion into novel habitats remain poorly understood at a genomic scale. Lizards from the genus Anolis are typically tropical, and the green anole (Anolis carolinensis) constitutes an exception since it expanded into temperate North America from subtropical Florida. Thus, we used the green anole as a model to investigate signatures of selection associated with colonization of a new environment, namely temperate North America. To this end, we analysed 29 whole‐genome sequences, covering the entire native range of the species. We used a combination of recent methods to quantify both positive and balancing selection in northern populations, including FST outlier methods, machine learning and ancestral recombination graphs. We naively scanned for genes of interest and assessed the overlap between multiple tests. Strikingly, we identified many genes involved in behaviour, suggesting that the recent successful colonization of northern environments may have been linked to behavioural shifts as well as physiological adaptation. Using a candidate genes strategy, we determined that genes involved in response to cold or behaviour displayed more frequently signals of selection, while controlling for local recombination rate, gene clustering and gene length. In addition, we found signatures of balancing selection at immune genes in all investigated genetic groups, but also at genes involved in neuronal and anatomical development. [ABSTRACT FROM AUTHOR]

Landscape heterogeneity plays an important role in population structure and divergence, particularly for species with limited vagility. Here, we used a landscape genetic approach to identify how landscape and environmental variables affect genetic structure and color morph frequency in a polymorphic salamander. The eastern red‐backed salamander, Plethodon cinereus, is widely distributed in northeastern North America and contains two common color morphs, striped and unstriped, that are divergent in ecology, behavior, and physiology. To quantify population structure, rates of gene flow, and genetic drift, we amplified 10 microsatellite loci from 648 individuals across 28 sampling localities. This study was conducted in northern Ohio, where populations of P. cinereus exhibit an unusually wide range of morph frequency variation. To test whether genetic distance was more correlated with morph frequency, elevation, canopy cover, waterways, ecological niche or geographic distance, we used resistance distance and least cost path analyses. We then examined whether landscape and environmental variables, genetic distance or geographic distance were correlated with variation in morph frequency. Tests for population structure revealed three genetic clusters across our sampling range, with one cluster monomorphic for the striped morph. Rates of gene flow and genetic drift were low to moderate across sites. Genetic distance was most correlated with ecological niche, elevation and a combination of landscape and environmental variables. In contrast, morph frequency variation was correlated with waterways and geographic distance. Thus, our results suggest that selection is also an important evolutionary force across our sites, and a balance between gene flow, genetic drift and selection interact to maintain the two color morphs. [ABSTRACT FROM AUTHOR]

Efforts to mitigate the current biodiversity crisis require a better understanding of how and why humans value other species. We use Internet query data and citizen science data to characterize public interest in 621 bird species across the United States. We estimate the relative popularity of different birds by quantifying how frequently people use Google to search for species, relative to the rates at which they are encountered in the environment. In intraspecific analyses, we also quantify the degree to which Google searches are limited to, or extend beyond, the places in which people encounter each species. The resulting metrics of popularity and geographic specificity of interest allow us to define aspects of relationships between people and birds within a cultural niche space. We then estimate the influence of species traits and socially constructed labels on niche positions to assess the importance of observations and ideas in shaping public interest in birds. Our analyses show clear effects of migratory strategy, color, degree of association with bird feeders, and, especially, body size on niche position. They also indicate that cultural labels, including "endangered," "introduced," and, especially, "team mascot," are strongly associated with the magnitude and geographic specificity of public interest in birds. Our results provide a framework for exploring complex relationships between humans and other species and enable more informed decision-making across diverse bird conservation strategies and goals. [ABSTRACT FROM AUTHOR]

What are the ecological consequences of allopolyploid speciation in ferns? In northeastern North America, this question is relevant to the Adiantum pedatum complex. Adiantum viridimontanum (Green Mountain maidenhair fern) is an allotetraploid hybrid derived from a sterile cross between the serpentine-restricted diploid species A. aleuticum (Aleutian maidenhair fern) and the rich-woods diploid species A. pedatum (northern maidenhair fern). In this study, we characterized the ecological niche of the allotetraploid hybrid maidenhair fern relative to the niches of its two progenitors by establishing 48 survey plots at 13 sites where the three species occur in Vermont and by measuring a set of ecological attributes in each plot, including the habitat type, light availability, topography, substrate characteristics, and soil chemistry. These data were analyzed using principal component analysis (PCA) to characterize the multivariate ecological niche of each species as circumscribed by the position of survey plots in environmental space. Along the first principal component, the ecological niche of the allotetraploid was situated between those of its progenitors in environmental space, closely overlapping the niche of A. aleuticum and slightly overlapping that of A. pedatum. Along the second principal component, a portion of the ecological niche of the allotetraploid was transgressive relative to the niches of its progenitors in environmental space; in geographic space, these survey plots correspond to northern hardwood serpentine-influenced forests, a habitat type that is novel for the species complex. Thus, the ecological outcome of allopolyploid speciation in the A. pedatum complex appears to include elements of both niche intermediacy and niche expansion into novel habitats. [ABSTRACT FROM AUTHOR]

Copyright of Therya is the property of Asociacion Mexicana de Mastozoologia, A. C. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract The classic traits of modern horses (Equidae) – large body size, high-crowned teeth (hypsodonty), and a single toe (monodactyly) – are often considered adaptations to grassland environments. However, extinct horses that varied in these three traits overlapped geographically for millions of years during the Miocene and Pliocene. It has been hypothesized that co-occurring horse species partitioned habitats, with large-bodied, hypsodont, and monodactyl equids dominating open grasslands, while equids with different combinations of traits lived in more wooded areas. We tested for the presence of broad-scale habitat partitioning by compiling a large database of North American horse fossil occurrences with data on trait state (body size, hypsodonty index, and toe number) and paleoenvironment (derived from paleovegetation records). Null modeling of niche overlap in each of the North American Land Mammal Ages of the Miocene and Pliocene revealed that taxonomic and trait-based groups show no differences in habitat occupancy. Cluster dendrograms visualizing niche overlap showed that some ecological guilds shared derived traits, but derived traits were not associated exclusively with grassland habitats. Trait values are not predicted by the proportion of grassland habitats in time bins. Further, the three traits show no co-evolution across the equid tree when corrected for phylogenetic relatedness. Together, these results suggest that the evolution of large body size, hypsodonty, and monodactyly in equids was not due to a shared selective regime in response to expanding grassland habitats; instead, these traits may have evolved separately, likely due to a variety of small-scale selective pressures acting across the variety of habitats present in the Miocene and Pliocene. Highlights • Low niche overlap was found between fossil horse genera and trait-based groups. • Grassland habitat occupancy cannot be inferred from derived equid traits. • Body size, hypsodonty index, and degree of toe reduction are not significantly correlated. [ABSTRACT FROM AUTHOR]