Find research datasets worth reusing

opencc-zeroNov 2023View details →

Data from: Genetic signatures of lineage fusion closely resemble population decline

Accurate interpretation of the genetic signatures of past demographic events is crucial for reconstructing evolutionary history. Lineage fusion (complete merging, resulting in a single panmictic population) is a special case of secondary contact that is seldom considered. Here, the circumstances under which lineage fusion can be distinguished from population size constancy, growth, bottleneck, and decline were investigated. Multi-locus haplotype data were simulated under models of lineage fusion with different divergence versus sampling lag times (D:L ratios). These pseudo-observed datasets also differed in their allocation of a fixed amount of sequencing resources (number of sampled alleles, haplotype length, number of loci). Distinguishability of lineage fusion versus each of 10 untrue non-fusion scenarios was quantified based on six summary statistics (neutrality tests). Some datasets were also analyzed using extended Bayesian skyline plots. Results showed that signatures of lineage fusion very closely resemble those of decline—high distinguishability was generally limited to the most favorable scenario (D:L = 9), using the most sensitive summary statistics (FS and ZnS), coupled with the optimal sequencing resource allocation (maximizing number of loci). Also, extended Bayesian skyline plots often erroneously inferred population decline. Awareness of the potential for lineage fusion to carry the hallmarks of population decline is critical.

opencc-zeroNov 2023View details →

Data from: Quantifying the impacts of management and herbicide resistance on regional plant population dynamics in the face of missing data

A key challenge in the management of populations is to quantify the impact of interven-tions in the face of environmental and phenotypic variability. However, accurate estima-tion of the effects of management and environment, in large-scale ecological research is often limited by the expense of data collection, the inherent trade-off between quality and quantity, and missing data. In this paper we develop a novel modelling framework, and demographically informed imputation scheme, to comprehensively account for the uncertainty generated by miss-ing population, management, and herbicide resistance data. Using this framework and a large dataset (178 sites over 3 years) on the densities of a destructive arable weed (Alo-pecurus myosuroides) we investigate the effects of environment, management, and evolved herbicide resistance, on weed population dynamics. In this study we quantify the marginal effects of a suite of common management prac-tices, including cropping, cultivation, and herbicide pressure, and evolved herbicide re-sistance, on weed population dynamics. Using this framework, we provide the first empirically backed demonstration that herbi-cide resistance is a key driver of population dynamics in arable weeds at regional scales. Whilst cultivation type had minimal impact on weed density, crop rotation, and earlier cultivation and drill dates consistently reduced infestation severity. Synthesis and applications: As we demonstrate that high herbicide resistance levels can produce extremely severe weed infestations, monitoring of herbicide resistance is a pri-ority for famers across western Europe. Furthermore, developing non chemical control methods is essential to control current weed populations, and prevent further resistance evolution. We recommend that planning interventions that center on crop rotation and incorporate spring sewing and cultivation to provide the best reductions in weed densi-ties. More generally, by directly accounting for missing data our framework permits the analysis of management practices with data that would otherwise be severely compro-mised.

zenodo36/100

Data file for Massé et al.'s article, "Unraveling the Life History of Past Populations through Hypercementosis: Insights into Cementum Apposition Patterns and Possible Etiologies using Micro-CT and Confocal Microscopy".

This repository provides a supporting data file for the following research article: Massé L., d’Incau E., Souron A., Vanderesse N., Santos F., Maureille B., Le Cabec A. (2024) Unraveling the Life History of Past Populations through Hypercementosis: Insights into Cementum Apposition Patterns and Possible Etiologies Using Micro-CT and Confocal Microscopy. Biology, 13, 43. doi: <a href="https://doi.org/10.3390/biology13010043" target="_blank" rel="nofollow noopener noreferrer">10.3390/biology13010043</a> For the detailed statistical analyses performed using this dataset, see Supporting Information 1 of the article.

opencc-by-4.0Dec 2023View details →

zenodo36/100

Data for section 3.2 of Stellar Population Properties in the Stellar Streams Around SPRC047

Supplementary (input and output) data for Section 3.2 ("Measurement Uncertainties in the Deconvolved Image") of the paper "Stellar Population Properties in the Stellar Streams Around SPRC047", accepted for publication in ApJ and available in <a href="https://arxiv.org/abs/2312.05358" target="_blank" rel="noopener">arXiv:2312.05358.</a> The source code for this project is publicly available <a href="https://gitlab.com/makhlaghi/sprc047-stream-clumps-photometry" target="_blank" rel="noopener">on Gitlab</a> and is archived on<a href="https://archive.softwareheritage.org/swh:1:dir:882514891cdcfc08261409352437bc6b8a836b8b;origin=https://gitlab.com/makhlaghi/sprc047-stream-clumps-photometry;visit=swh:1:snp:11cb02c374d7856028c57fb7312b60531f1be2e6;anchor=swh:1:rev:5d81b833931e58732627c06998c2488e6d2a8fb7" target="_blank" rel="noopener"> SoftwareHeritage</a> for longevity. A brief description of the contents in this repository are given below. Note that because the AWMLE deconvolution code is not yet publicly released, the second two files below are necessary (they are used by the reproducible Makefile of this section <a href="https://gitlab.com/makhlaghi/sprc047-stream-clumps-photometry" target="_blank" rel="noopener">on Gitlab</a>). <ul> <li><a href="../records/10397812/files/sprc047_3.6um-bck.fits?download=1">sprc047_3.6um-bck.fits</a>: Spitzer image of SPRC047.</li> <li><a href="../records/10397812/files/deconvolved-it75.fits?download=1">deconvolved-it75.fits</a>: The deconvolved Spitzer image.</li> <li><a href="../records/10397812/files/deconvolved-simulated.tar.gz?download=1">deconvolved-simulated.tar.gz</a>: 100 realizations of random noise over a point-like source used to estimate the error of the deconvolved measurements.</li> </ul>

opencc-by-4.0Dec 2023View details →

opencc-zeroDec 2023View details →

Data from: Multi-generation genetic contributions of immigrants reveal cryptic elevated and sex-biased effective gene flow within a natural meta-population

Impacts of immigration on micro-evolution and population dynamics fundamentally depend on net rates and forms of resulting gene flow into recipient populations. Yet, the degrees to which observed rates and sex ratios of physical immigration translate into multi-generational genetic legacies have not been explicitly quantified in natural meta-populations, precluding inference on how movements translate into effective gene flow and eco-evolutionary outcomes. Our analyses of three decades of complete song sparrow (Melospiza melodia) pedigree data show that multi-generational genetic contributions from regular natural immigrants substantially exceeded those from contemporary natives, consistent with heterosis-enhanced introgression. Further, while contributions from female immigrants exceeded those from female natives by up to three-fold, male immigrants' lineages typically went locally extinct soon after arriving. Both the overall magnitude, and the degree of female bias, of effective gene flow therefore greatly exceeded those which would be inferred from observed physical arrivals, reshaping the eco-evolutionary implications of immigration.

Data from: Combining the resurrection approach with transplant experiments to investigate adaptation of plant populations to environmental change

Recent climatic changes, such as more frequent droughts and heatwaves, can lead to rapid evolutionary adaptations in plant populations. Such rapid evolution can be investigated using the resurrection approach by comparing plants raised from stored ancestral and contemporary seeds from the same population. This approach has so far only been used in common garden experiments, allowing it to reveal genetic differentiation but not adaptation. In this study, we performed a novel approach by testing for evolutionary adaptation in natural plant populations using a resurrection study in combination with in situ transplantations. We cultivated seedlings from ancestors (23–26 years old) and contemporary descendants of three perennial species (Melica ciliata, Leontodon hispidus and Clinopodium vulgare) from calcareous grasslands in the greenhouse and transplanted them back to their collection sites. In addition, we sowed seeds of ancestors and descendants of two species (L. hispidus and C. vulgare) to the collection sites in order to investigate germination rates. In transplanted M. ciliata seedlings, we observed lower mortality and larger plant size in descendants compared to ancestors. This indicates that descendants are better adapted than ancestors to the current environmental conditions, which proved to be exceptionally hot and dry during the study period. Descendants of C. vulgare seedlings tended to be smaller and descendants of L. hispidus seedlings produced fewer leaves compared to their ancestors in their contemporary environmental conditions. In C. vulgare and L. hispidus, we found evolution towards faster germination, and especially descendant seeds of C. vulgare were better adapted to the unfavourable conditions during the experimental period. Concluding, we demonstrate that our novel approach to combine resurrection ecology with transplant experiments is a promising avenue to rigorously test for evolutionary adaptations in changing environments.

SNP data for F2 population derived from Oryza rufipogon and O. nivara

To elucidate the genetic architecture underlying phenotypic divergence is essential to the understanding of ecological adaptation and speciation. Two wild rice species (O. rufipogon and O. nivara) are a progenitor-daughter species pair with ecological divergence and provide a unique system for studying ecological adaptation/speciation. Here, we constructed a high-resolved linkage map and conducted a quantitative trait locus (QTL) analysis of 19 phenotypic traits using an F2 population generated from a cross between the perennial O. rufipogon and annual O. nivara. We identified 113 QTLs associated with interspecific divergence of 16 quantitative traits, with effect sizes ranging from 1.61% to 34.1% in terms of the percentage of variation explained (PVE). The distribution of effect sizes of QTLs followed a negative exponential, suggesting that a few genes of large effect and many genes of small effect were responsible for the phenotypic divergence. We observed 18 clusters of QTLs (QTL hotspots), with each involving multiple adaptive traits, demonstrating the importance of coinheritance of loci/genes in ecological adaptation/speciation. Analysis of effect direction and v-test statistics revealed that interspecific differentiation of most traits was driven by divergent natural selection, supporting the argument that ecological adaptation/speciation would proceed rapidly under coordinated selection on multiple traits.

Data from: Contrasting patterns of female house mouse spatial organisation among outbreaking and stable populations

The size and distribution of home ranges reflects how individuals within a population use, defend, and share space and resources, and may thus be an important predictor of population-level dynamics. In eruptive species like the house mouse in Australian grain growing regions, contrasting space use between stable and outbreaking populations allows us to test predictions regarding social or life history strategies that may contribute to an outbreak. In this study we use spatially explicit capture-recapture models to compare home range overlap (as a proxy for territoriality) in female mice from populations showing different outbreak trajectories. We found that female space use in spring varied between outbreaking and stable populations. Our analysis indicated greater home range overlap in populations with stable trajectories compared to those that would later experience an outbreak, suggesting females in these stable populations may have had greater potential for cooperative group formation as indicated by shared space use. We discuss the results with respect to intrinsic factors, such as kin structure, with potential implications for better predicting mouse outbreaks at a microgeographic scale.

Replication data for global population profile of tropical cyclone exposure during 2002 and 2019

Tropical cyclones have far-reaching impacts on livelihoods and population health that often persist years after the event. Characterizing the demographic and socioeconomic profile and the vulnerabilities of the exposed populations is essential to assess health and other risks associated with future tropical cyclone events. Estimates of exposure to tropical cyclones are often regional rather than global and do not consider population vulnerabilities. Here, we combine spatially resolved annual demographic estimates with tropical cyclone wind fields estimates to construct a global profile of the populations exposed to tropical cyclones between 2002 and 2019. We find that approximately 560 million people are exposed yearly and that the number of people exposed has increased across all cyclone intensities over the study period. The age distribution of those exposed has shifted away from children (under-5) and towards older people (over-60) in recent years compared to the early 2000s. Populations exposed to tropical cyclones are more socioeconomically deprived than those unexposed within the same country, and this relationship is more pronounced for people exposed to higher intensity storms. By characterizing the patterns and vulnerabilities of populations exposed to tropical cyclones, our results can help identify mitigation strategies and assess the global burden and future risks of tropical cyclones.

Data from: Plant-soil microbe feedbacks depend on distance and ploidy in a mixed cytotype population of Larrea tridentata

Premise of the study Theory predicts that mixed ploidy populations should be short-lived due to strong fitness disadvantages for the rare ploidy. However, mixed ploidy populations are common, suggesting that the fitness costs for rare ploidies are counterbalanced by ecological benefits that emerge when rare. We investigated whether differences in ecological interactions with soil microbes help to maintain a tetraploid-hexaploid population of Larrea tridentata (creosote bush) in the Sonoran Desert, California, USA, where prior work documented ploidy-specific root-associated microbes. Methods We used a plant-soil feedback (PSF) experiment to test whether host-specific soil microbes can alter the outcomes of intra-ploidy vs. inter-ploidy competition. Host-specific soil microbes can build up over time; thus, distance from a host plant can affect the fitness of nearby plants. Key results Seedlings grown in soils from near plants of a different ploidy produced greater biomass relative to seedlings grown in soils from near plants of the same ploidy. Moreover, seedlings grown in soils from near plants of a different ploidy produced greater biomass than those grown in soils from further away from plants of a different ploidy. This suggests the ecological consequences of PSF may facilitate the persistence of mixed ploidy populations. Conclusions This is the first evidence, to our knowledge, consistent with plant-soil microbe feedback as a viable mechanism to maintain the coexistence of multiple ploidy levels in a single population.

Data from: Cross ocean-basin population genetic dynamics in a pelagic top predator of high conservation concern, the oceanic whitetip shark, Carcharhinus longimanus

The oceanic whitetip shark, Carcharhinus longimanus, is a Critically Endangered, circumtropical, and highly migratory, pelagic shark. Yet, little information exists on its population genetic dynamics to guide conservation management practice. We present a first worldwide, mitochondrial and nuclear DNA assessment of the population genetic status of this imperiled species based on sequences of the complete mitochondrial control region (n = 173) and partial ND4 gene (n = 172), and genotypes from 12 nuclear microsatellites (n = 164). Statistically significant mitochondrial and nuclear DNA population genetic differentiation was detected across all marker datasets between Western Atlantic and Indo-Pacific oceanic whitetip sharks. Additionally, our data, combined with previously published, partial (701-base pairs) mitochondrial control region sequences from additional locations in the Atlantic and Indian Oceans, confirmed significant matrilineal population structure between the Western and Eastern Atlantic. The combined data also provisionally (i.e., with FST but not ΦST) indicated differentiation between Western North and Central-South Atlantic sharks, pointing to the need for further assessment in this region. Matrilineal differentiation was also detected between Indian and Pacific Ocean sharks via pairwise analyses, albeit with the ND4 gene sequence only (ΦST = 0.051; FST = 0.092). Limited sampling in the Pacific leaves open questions about the connectivity dynamics in this large region. Despite the presence of geographic population genetic structure, the mitochondrial data showed no evidence of across ocean basin phylogeographic lineages. A provisional assessment of mitochondrial and nuclear genetic diversity indicated the oceanic whitetip shark's status falls in the middle to upper ranges compared to other shark species, potentially lending some optimism for the present adaptability and resiliency of this species if strong conservation measures are effectively implemented.

Data from: The contribution of carbon budget to masting intervals in Veratrum album populations inhabiting different elevations

Premise: Mast flowering/seeding is often more extreme in lower-resource environments, such as alpine compared to lowland habitats. We studied a masting herb which had less extreme masting at higher elevations, and tested if this difference could be explained by higher photosynthetic productivity and/or lower reproductive investment at the higher elevation sites. Methods: We examined the relationship between flowering intervals and carbon budget (i.e., the balance between reproductive investment and annual carbon fixation) in a masting herb, Veratrum album subsp. oxysepalum, across five lowland and six alpine populations in northern Japan. We evaluated the previous flowering histories of individual plants based on rhizome morphology and analyzed the masting patterns of individual populations. Total mass of the reproductive organs, as a proxy of reproductive investment, was compared between the lowland and alpine populations. Annual carbon fixation was estimated based on photosynthetic capacity, total leaf area per plant, and seasonal transition of light availability. Results: Interval between high-flowering years was shorter and total reproductive investment was smaller in the alpine than in the lowland populations. Owing to its high photosynthetic capacity and continuous bright conditions, annual carbon fixation per plant was 1.5 times greater at the alpine habitat than at the lowland habitat. These results suggest that V. album alpine populations have shorter flowering intervals than lowland populations due to faster recovery from energy loss after reproduction. Conclusions: Our study demonstrated that masting intervals in V. album populations can be explained by habitat-specific carbon budget balances.

Data from: Rapid evolution of flower phenology and clonality in restored populations of multiple grassland species

<ol> <li>Restoration of terrestrial ecosystems often requires re-introduction of plants. In restored sites, the plants often face environments that differ from those of natural populations. This can affect plant traits, reduce performance and impose novel selection pressures. As a response, restored populations might rapidly evolve and adapt to the novel conditions. This may enhance population survival and contribute to restoration success but has been rarely tested so far.</li> <li>Here, we focused on populations of three grassland species restored 20 years ago (Galium wirtgenii, Inula salicina and Centaurea jacea) by the transfer of green hay, and compared them with donor populations that were the source of the hay. We measured plants both in situ and in a common garden under control and three stress conditions.</li> <li>In-situ, plants in restored sites flowered earlier than plants in donor sites in two out of the three species. In the common garden, plants from the restored populations flowered earlier (in Galium) or showed increased plasticity of clonal propagation in response to clipping (in Inula). Both these traits suggest rapid adaptation to the contrasting mowing regimes in restored in comparison to the donor sites. In Centaurea, we detected no differentiation, neither in situ nor in the common garden.</li> <li> Synthesis and applications: Grassland plants introduced into degraded habitats within the framework of ecological restoration may quite commonly evolve in response to novel selection pressures at restored sites. This rapid evolution likely increases the plant's adaptation to the new conditions of the restored grassland and thus enhances the likelihood of survival of the population and ultimately restoration success. While most practitioners do not consider evolution to be part of restoration, our finding highlights that restored populations of grassland species can be systems with considerable eco-evolutionary dynamics.</li> </ol>

Data from: Abundance models of endemic birds of the Sierra Nevada de Santa Marta, northern South America, suggest small population sizes and dependence on montane elevations

Abundance measures are almost non-existent for several bird species threatened with extinction, particularly range-restricted Neotropical taxa, for which estimating population sizes can be challenging. Here we use data collected over nine years to explore the abundance of 11 endemic birds from the Sierra Nevada de Santa Marta (SNSM), one of Earth's most irreplaceable ecosystems. We established 99 transects in the "Cuchilla de San Lorenzo" Important Bird Area within native forest, early successional vegetation, and areas of transformed vegetation by human activities. A total of 763 bird counts were carried out covering the entire elevation range in the study area (~175–2650 m). We applied hierarchical distance-sampling models to assess elevation- and habitat-related variation in local abundance and obtain values of population density and total and effective population size. Most species were more abundant in the montane elevational range (1800–2650 m). Habitat-related differences in abundance were only detected for five species, which were more numerous in either early succession, secondary forest, or transformed areas. Inferences of effective population size indicated that at least four endemics likely maintain populations no larger than 15,000–20,000 mature individuals. Estimates of species' area of occupancy and effective population size were lower than most values previously described, a possible consequence of increasing anthropogenic threats. At least four of the endemics exceeded criteria for threatened species listing and a thorough evaluation of their extinction risk should be conducted. Population strongholds for most of the study species were located on the northern and western slopes of the SNSM between 1500–2700 m. We highlight the urgent need for facilitating effective protection of native vegetation in premontane and montane ecosystems to safeguard critical habitats for the SNSM's endemic avifauna. Follow-up studies collecting abundance data across the SNSM are needed to obtain precise range-wide density estimations for all species.

Data and code from: Accounting for unobserved population dynamics and aging error in close-kin mark-recapture assessments

Obtaining robust estimates of population abundance is a central challenge hindering the conservation and management of many threatened and exploited species. Close-kin mark-recapture (CKMR) is a genetics-based approach that has strong potential to improve monitoring of data-limited species by enabling estimates of abundance, survival, and other parameters for populations that are challenging to assess. However, CKMR models have received limited sensitivity testing under realistic population dynamics and sampling scenarios, impeding application of the method in population monitoring programs and stock assessments. Here, we use individual-based simulation to examine how unmodeled population dynamics and aging uncertainty affect the accuracy and precision of CKMR parameter estimates under different sampling strategies. We then present adapted models that correct the biases that arise from model misspecification. Our results demonstrate that a simple base-case CKMR model produces robust estimates of population abundance with stable populations that breed annually; however, if a population trend or non-annual breeding dynamics are present, or if year-specific estimates of abundance are desired, a more complex CKMR model must be constructed. In addition, we show that CKMR can generate reliable abundance estimates for adults from a variety of sampling strategies, including juvenile-focused sampling where adults are never directly observed (and aging error is minimal). Finally, we apply a CKMR model that has been adapted for population growth and intermittent breeding to two decades of genetic data from juvenile lemon sharks (Negaprion brevirostris) in Bimini, Bahamas, to demonstrate how application of CKMR to samples drawn solely from juveniles can contribute to monitoring efforts for highly mobile populations. Overall, this study expands our understanding of the biological factors and sampling decisions that cause bias in CKMR models, identifies key areas for future inquiry, and provides recommendations that can aid biologists in planning and implementing an effective CKMR study, particularly for long-lived data-limited species.

Data for: Coherent long-term body-size responses across all Northwest Atlantic herring populations to warming and environmental change despite contrasting harvest and ecological factors

Body size is a key component of individual fitness and an important factor in the structure and functioning of populations and ecosystems. Disentangling the effects of environmental change, harvest, and intra- and inter-specific trophic effects on body size remains challenging for populations in the wild. Herring in the Northwest Atlantic provide a strong basis for evaluating hypotheses related to these drivers given that they have experienced significant warming and harvest over the past century, while also having been exposed to a wide range of other selective constraints across their range. Using data on mean length-at-age 4 for the sixteen principal populations over a period of 53 cohorts (1962-2014), we fitted a series of empirical models for temporal and between-population variation in the response to changes in sea surface temperature. We find evidence for a unified cross-population response in the form of a parabolic function according to which populations in naturally warmer environments have responded more negatively to increasing temperature compared with those in colder locations. Temporal variation in residuals from this function was highly coherent among populations, further suggesting a common response to a large-scale environmental driver. The synchrony observed in this study system, despite strong differences in harvest and ecological histories among populations and over time, clearly indicates a dominant role of environmental change on size-at-age in wild populations, in contrast to commonly reported effects of fishing. This finding has important implications for the management of fisheries as it indicates that a key trait associated with population productivity may be under considerably less short-term management control than currently assumed. Our study, overall, illustrates the need for a comparative approach within species for inferences concerning the many possible effects on body size of natural and anthropogenic drivers in the wild.

Data from: Metabarcoding of fecal pellets in wild muskox populations reveals negative relationships between microbiome and diet alpha diversity

Microbiome diversity and diet composition concomitantly influence species health, fitness, immunity, and digestion. In environments where diet varies spatially and temporally, microbiome plasticity may promote rapid host adaptation to available resources. For northern ungulates in particular, metabarcoding of noninvasively collected fecal pellets presents unprecedented insights into their diverse ecological requirements and niches by clarifying the interrelationships of microbiomes, key to deriving nutrients, in context of altered forage availability in changing climates. Muskoxen (Ovibos moschatus) are Arctic-adapted species that experience fluctuating qualities and quantities of vegetation. Geography and seasonality have been noted to influence microbiome composition and diversity in muskoxen, yet it is unclear how their microbiomes intersect with diet. Following observations from other species, we hypothesized increasing diet diversity would result in higher microbiome diversity in muskoxen. We assessed diet composition in muskoxen using three common plant metabarcoding markers and explored correlations with microbiome data. Patterns of dietary diversity and composition were not fully concordant among the markers used, yet all reflected the primary consumption of willows and sedges. Individuals with similar diets had more similar microbiomes, yet in contrast to most literature, yielded negative relationships between microbiome and diet alpha diversity. This negative correlation may reflect the unique capacities of muskoxen to survive solely on high-fiber Arctic forage and provide insight into their resiliency to exploit changing dietary resources in a rapidly warming Arctic altering vegetation diversity.

Data from: Distribution, population dynamics and potential impacts of the invasive snail, Tarebia granifera in aquatic ecosystems of north-eastern South Africa

Aquatic ecosystems globally have been invaded by molluscs. Tarebia granifera is a highly successful invader, often becoming the dominant aquatic invertebrate species in an invaded ecosystem. Resultingly, it has been suggested that T. granifera may have severe negative impacts on these invaded ecosystems. Limited information is available regarding the population structures and densities of T. granifera, particularly in invaded countries such as South Africa, and information on this could assist in developing management and control strategies for this invasive species. The aim of the present study was to assess the current distribution, densities, and population structures of T. granifera in invaded habitats on the Limpopo and Phongolo River systems, South Africa. This was accomplished by collecting aquatic benthic molluscs from sites across these systems. Water quality parameters were measured at each site and water samples collected for chemical nutrient analyses. The density of snails was determined for each site and the population size and structure as well as birth rate was calculated for T. granifera. Tarebia granifera was found to be the dominant molluscan species in habitats where it was present and all size classes from new-born to mature adults were found throughout at some of the highest densities globally. Worryingly, native molluscan species, were often absent or in much lower densities than reported in literature at sites where T. granifera was present, suggesting a negative effect on the native molluscan density and diversity. Contrary to most previous studies, there were no significant correlations between T. granifera and the selected water quality parameters. Higher densities and new-born recruitment of T. granifera were observed in the spring than autumn, likely in response to shifts in environmental conditions. This study provides crucial insights into the population structure and dynamics of T. granifera in invaded habitats, particularly for relatively newly invaded regions such as southern Africa.

opencc-zeroMar 2024View details →

Data for: Climate warming and projected loss of thermal habitat volume in lake populations of brook trout

We applied an ensemble of climate warming models and the seasonal temperature profile model for lakes (STM) to assess changes in brook trout thermal habitat volume (THV) among lakes (N=100) within a large, protected area under two climate warming scenarios, RCP 4.5 and RCP 8.5. Brook trout thermal habitat was defined as 9-17°C. Climate warming projections for the balance of this century, regardless of RCP category, will result in the loss of brook trout habitat in lakes that range widely in size. THV loss will be most extensive in lakes that are relatively shallow given their surface area. By 2071-2100 under RCP 4.5, the 90th percentile of THV loss = 31% vs. 63% under RCP 8.5. By the century's end under RCP 8.5, the protected area landscape will be a matrix of lakes with some serving as climate refugia (with reduced THV) and others having severe reductions in THV (>90th percentile THV loss).