| 1. |
- Cockerill, Christopher Alan, 1994-, et al.
(författare)
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Genomic Consequences of Fragmentation in the Endangered Fennoscandian Arctic Fox (Vulpes lagopus)
- 2022
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Ingår i: Genes. - : MDPI AG. - 2073-4425. ; 13:11
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Tidskriftsartikel (refereegranskat)abstract
- Accelerating climate change is causing severe habitat fragmentation in the Arctic, threatening the persistence of many cold-adapted species. The Scandinavian arctic fox (Vulpes lagopus) is highly fragmented, with a once continuous, circumpolar distribution, it struggled to recover from a demographic bottleneck in the late 19th century. The future persistence of the entire Scandinavian population is highly dependent on the northernmost Fennoscandian subpopulations (Scandinavia and the Kola Peninsula), to provide a link to the viable Siberian population. By analyzing 43 arctic fox genomes, we quantified genomic variation and inbreeding in these populations. Signatures of genome erosion increased from Siberia to northern Sweden indicating a stepping-stone model of connectivity. In northern Fennoscandia, runs of homozygosity (ROH) were on average ~1.47-fold longer than ROH found in Siberia, stretching almost entire scaffolds. Moreover, consistent with recent inbreeding, northern Fennoscandia harbored more homozygous deleterious mutations, whereas Siberia had more in heterozygous state. This study underlines the value of documenting genome erosion following population fragmentation to identify areas requiring conservation priority. With the increasing fragmentation and isolation of Arctic habitats due to global warming, understanding the genomic and demographic consequences is vital for maintaining evolutionary potential and preventing local extinctions.
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| 2. |
- Måsviken, Johannes, 1990-, et al.
(författare)
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Elevational variation of spider and insect communities in the Swedish mountains
- 2023
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Ingår i: Ecosphere. - 2150-8925. ; 14:6
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Tidskriftsartikel (refereegranskat)abstract
- Mountain topography gives rise to often dramatic climate-driven elevation gradients in primary productivity, which can generate substantial biodiversity variation. Therefore, mountain areas may be particularly useful for evaluating the ecological consequences of climate change. Arthropods are the most diverse animal phylum, which play important roles in most ecosystems. However, despite their ecological importance, we have limited information on how arthropods vary along elevation gradients. We investigated how taxonomic richness, taxonomic composition, and spatial structuring of spider and insect communities varied along elevation gradients and among three geographic locations in a mountain region of northern Sweden. The locations provided a latitude gradient spanning approximately 3° (from 62° N to 65° N), but were otherwise selected to contain similar environmental characteristics. Taxonomic richness of both spiders and insects declined monotonically with increasing elevation, and there were limited differences between the geographic locations in such declines. Taxonomic composition varied with elevation for both taxonomic groups, but also differed among the three sites. Linyphiid spiders were more widely distributed along the elevation gradients than other spider taxa, whereas a broad taxonomic range of insects occurred over almost all elevations. We observed nested as well as modular spatial distributions of both spider and insect communities along the elevation gradients. While the modular patterns suggest that species turnover has generated distinct communities at different elevations, some generalist species were still widespread throughout large parts of the gradients. Our results point to smaller differences among geographic locations than among taxonomic groups in how taxonomic richness and community structuring varied with elevation. We interpret these results as support for taxonomically specific adaptations to environmental conditions being important for structuring arthropod communities. We also suggest that climate-driven changes to arthropod communities in mountain environments may be regulated by two not mutually exclusive processes, one in which generalist species may become more dominant and shift their ranges upward and one in which high-elevation specialists may go extinct because of increasingly fragmented habitats.
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| 3. |
- Måsviken, Johannes, 1990-, et al.
(författare)
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The relative importance of abiotic and biotic environmental conditions for taxonomic, phylogenetic, and functional diversity of spiders across spatial scales
- 2023
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Ingår i: Oecologia. - 0029-8549 .- 1432-1939. ; 202:2, s. 261-273
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Tidskriftsartikel (refereegranskat)abstract
- Both abiotic and biotic conditions may be important for biodiversity. However, their relative importance may vary among different diversity dimensions as well as across spatial scales. Spiders (Araneae) offer an ecologically relevant system for evaluating variation in the relative strength abiotic and biotic biodiversity regulation. We quantified the relative importance of abiotic and biotic conditions for three diversity dimensions of spider communities quantified across two spatial scales. Spiders were surveyed along elevation gradients in northern Sweden. We focused our analysis on geomorphological and climatic conditions as well as vegetation characteristics, and quantified the relative importance of these conditions for the taxonomic, phylogenetic, and functional diversity of spider communities sampled across one intermediate (500 m) and one local (25 m) scale. There were stronger relationships among diversity dimensions at the local than the intermediate scale. There were also variation in the relative influence of abiotic and biotic conditions among diversity dimensions, but this variation was not consistent across spatial scales. Across both spatial scales, vegetation was related to all diversity dimensions whereas climate was important for phylogenetic and functional diversity. Our study does not fully support stronger abiotic regulation at coarser scales, and conversely stronger abiotic regulation at more local scales. Instead, our results indicate that community assembly is shaped by interactions between abiotic constrains in species distributions and biotic conditions, and that such interactions may be both scale and context dependent.
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| 4. |
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| 5. |
- von Seth, Johanna, et al.
(författare)
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Genomic trajectories of a near-extinction event in the Chatham Island black robin
- 2022
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Ingår i: BMC Genomics. - : Springer Science and Business Media LLC. - 1471-2164. ; 23
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Tidskriftsartikel (refereegranskat)abstract
- Background: Understanding the micro-evolutionary response of populations to demographic declines is a major goal in evolutionary and conservation biology. In small populations, genetic drift can lead to an accumulation of deleterious mutations, which will increase the risk of extinction. However, demographic recovery can still occur after extreme declines, suggesting that natural selection may purge deleterious mutations, even in extremely small populations. The Chatham Island black robin (Petroica traversi) is arguably the most inbred bird species in the world. It avoided imminent extinction in the early 1980s and after a remarkable recovery from a single pair, a second population was established and the two extant populations have evolved in complete isolation since then. Here, we analysed 52 modern and historical genomes to examine the genomic consequences of this extreme bottleneck and the subsequent translocation.Results: We found evidence for two-fold decline in heterozygosity and three- to four-fold increase in inbreeding in modern genomes. Moreover, there was partial support for temporal reduction in total load for detrimental variation. In contrast, compared to historical genomes, modern genomes showed a significantly higher realised load, reflecting the temporal increase in inbreeding. Furthermore, the translocation induced only small changes in the frequency of deleterious alleles, with the majority of detrimental variation being shared between the two populations.Conclusion: Our results highlight the dynamics of mutational load in a species that recovered from the brink of extinction, and show rather limited temporal changes in mutational load. We hypothesise that ancestral purging may have been facilitated by population fragmentation and isolation on several islands for thousands of generations and may have already reduced much of the highly deleterious load well before human arrival and introduction of pests to the archipelago. The majority of fixed deleterious variation was shared between the modern populations, but translocation of individuals with low mutational load could possibly mitigate further fixation of high-frequency deleterious variation.
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| 6. |
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| 7. |
- von Seth, Johanna, 1989-
(författare)
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The use of museum specimens in conservation genomics
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the face of an increasing number of species being threatened by extinction, museum collections can constitute a powerful resource for acquiring genomic data of endangered taxa. By utilising datasets that combine genomes from present-day populations with those from historical timepoints, several questions relevant for conservation can be investigated. In this thesis, I made use of museum specimens by combining historical and modern genomes to shed light on the genomic status of four species of conservation concern. The thesis focuses on change in genome diversity, inbreeding, and mutational load, but also divergence and structure of extinct populations and present-day populations from which sampling is difficult. Since the 1920’s, the now extinct Sumatran rhinoceros (Dicerorhinus sumatrensis) population on the Malay Peninsula likely experienced genomic erosion (chapter I). Inbreeding increased almost four-fold, and was possibly accompanied by inbreeding depression causing premature deaths and/or lowered reproductive success. Mutational load was higher in the only two remaining populations on Borneo and Sumatra, but as genomic diversity was also relatively high, a large portion of the species’ evolutionary potential might be retained if population sizes can recover quickly. The extinct New Zealand mainland kākāpō (Strigops habroptilus) population comprised higher genomic diversity and lower inbreeding, but higher mutational load, compared to the only extant population on Stewart Island (chapter II). Demographic reconstruction revealed a continuous population decline on Stewart Island since the population split between the mainland and Stewart Island populations around 10,000 years ago, and simulations demonstrated that this could have facilitated a higher efficacy of purifying selection on Stewart Island. While the arctic fox (Vulpes lagopus) is of least concern worldwide, the peripheral Scandinavian population has been threatened by extinction since the early 1900’s. A substantial increase in inbreeding was found in all Scandinavian subpopulations, but was most pronounced in southern Scandinavia (chapter III). In spite of ongoing inbreeding in the past century, genomic diversity remained stable in central and northern Scandinavia, possibly owing to post-bottleneck gene flow from Russia. The population bottleneck of a single breeding pair in the Chatham Island black robin (Petroica traversi) caused a four-fold increase in inbreeding and halved genomic diversity, but caused only minor changes in mutational load (chapter IV). In the light of population history, this suggests that prolonged periods of small population size have facilitated possibilities for purging of genetic load already prior to the historical decline. Overall, this thesis highlights not only the extensive genomic impact that anthropogenic-driven declines have had on genomic diversity of endangered animals, but also that the effect on mutational load varies between taxa.
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| 8. |
- Clark, M. S., et al.
(författare)
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Multi-omics for studying and understanding polar life
- 2023
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Ingår i: Nature Communications. - : NATURE PORTFOLIO. - 2041-1723. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Polar ecosystems are experiencing amongst the most rapid rates of regional warming on Earth. Here, we discuss ‘omics’ approaches to investigate polar biodiversity, including the current state of the art, future perspectives and recommendations. We propose a community road map to generate and more fully exploit multi-omics data from polar organisms. These data are needed for the comprehensive evaluation of polar biodiversity and to reveal how life evolved and adapted to permanently cold environments with extreme seasonality. We argue that concerted action is required to mitigate the impact of warming on polar ecosystems via conservation efforts, to sustainably manage these unique habitats and their ecosystem services, and for the sustainable bioprospecting of novel genes and compounds for societal gain.
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| 9. |
- Erlandsson, Rasmus, 1985-, et al.
(författare)
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Resources and predation : drivers of sociality in a cyclic mesopredator
- 2022
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Ingår i: Oecologia. - : Springer Science and Business Media LLC. - 0029-8549 .- 1432-1939. ; 198:2, s. 381-392
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Tidskriftsartikel (refereegranskat)abstract
- In socially flexible species, the tendency to live in groups is expected to vary through a trade-off between costs and benefits, determined by ecological conditions. The Resource Dispersion Hypothesis predicts that group size changes in response to patterns in resource availability. An additional dimension is described in Hersteinsson's model positing that sociality is further affected by a cost-benefit trade-off related to predation pressure. In the arctic fox (Vulpes lagopus), group-living follows a regional trade-off in resources' availability and intra-guild predation pressure. However, the effect of local fluctuations is poorly known, but offers an unusual opportunity to test predictions that differ between the two hypotheses in systems where prey availability is linked to intra-guild predation. Based on 17-year monitoring of arctic fox and cyclic rodent prey populations, we addressed the Resource Dispersion Hypothesis and discuss the results in relation to the impact of predation in Hersteinsson's model. Group-living increased with prey density, from 7.7% (low density) to 28% (high density). However, it remained high (44%) despite a rodent crash and this could be explained by increased benefits from cooperative defence against prey switching by top predators. We conclude that both resource abundance and predation pressure are factors underpinning the formation of social groups in fluctuating ecosystems.
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| 10. |
- Norén, Anna, 1989, et al.
(författare)
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Removal of organotin compounds and metals from Swedish marine sediment using Fenton’s reagent and electrochemical treatment
- 2022
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Ingår i: Environmental Science and Pollution Research. - : Springer Science and Business Media LLC. - 0944-1344 .- 1614-7499. ; 29:19, s. 27988-28004
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Tidskriftsartikel (refereegranskat)abstract
- Metal and tributyltin (TBT) contaminated sediments are problematic for sediment managers and the environment. This study is the first to compare Fenton’s reagent and electrochemical treatment as remediation methods for the removal of TBT and metals using laboratory-scale experiments on contaminated dredged sediment. The costs and the applicability of the developed methods were also compared and discussed. Both methods removed > 98% TBT from TBT-spiked sediment samples, while Fenton’s reagent removed 64% of the TBT and electrolysis 58% of the TBT from non-spiked samples. TBT in water phase was effectively degraded in both experiments on spiked water and in leachates during the treatment of the sediment. Positive correlations were observed between TBT removal and the added amount of hydrogen peroxide and current density. Both methods removed metals from the sediment, but Fenton’s reagent was identified as the most potent option for effective removal of both metals and TBT, especially from highly metal-contaminated sediment. However, due to risks associated with the required chemicals and low pH level in the sediment residue following the Fenton treatment, electrochemical treatment could be a more sustainable option for treating larger quantities of contaminated sediment.
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