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- Johannes, Måsviken, 1990-, et al.
(författare)
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Elevational variation of arthropod communities in the Swedish mountains
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Mountain topography gives rise to elevation gradients in both abiotic and biotic conditions, which can generate substantial biodiversity variation. Due to the close link between elevation and climate, mountain areas may be particularly useful for evaluating the ecological consequences of climate change. Arthropods are the most diverse animal phylum and play important roles in most ecosystems. Although arthropods are exposed to multiple stressors and are in global decline, we only have scant information on the distribution of arthropods along elevation gradients. We investigated how taxonomic richness, taxonomic composition, and spatial structuring of spider-, insect-, and springtail communities differed along elevation gradients at three sites in a high latitude mountain area. Taxonomic richness of spiders and insects declined monotonically with increasing elevation, but there were limited differences between sites in such declines. We did not observe any significant relationships between the taxonomic richness of springtails and elevation. Taxonomic composition did vary with elevation for all three taxonomic groups, and it also differed among the three sites. Spider- and insect communities were both spatially nested and showed spatial modularity 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. We observed no spatial structuring in springtail communities along elevation gradients. Our results point to smaller differences among sites 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 which high elevation specialists may go extinct because of increasingly fragmented habitats.
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| 4. |
- Måsviken, Johannes, 1990-
(författare)
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Biodiversity patterns and the processes regulating them along elevation gradients in the Swedish mountains
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Biodiversity describes the total variation of life and includes the taxonomic, genetic, and phenotypic differences among organisms. Variations of biodiversity in space and time may be driven by ecological, evolutionary, or neutral processes. The topography in mountains gives rise to substantial gradients in environmental conditions over short geographical distances. This makes them suitable for studies of how environmental conditions influence spatial variation in biodiversity. Additionally, climate change is stronger in high latitude and high elevation environments compared to the global average, which makes mountain environments particularly relevant systems for evaluating the biodiversity consequences of a changing climate. In this thesis I have assumed a declining primary productivity with increasing elevation and tested if this has led to related monotonic declines in biodiversity and a stronger environmental regulation of biodiversity at higher elevations. I pursued the following specific questions; (i) what are the patterns of biodiversity along elevation gradients in the Swedish mountains? (ii) do such patterns vary among organism groups at different trophic levels? (iii) what processes regulate biodiversity along elevation gradients in the Swedish mountains? To address these questions, I quantified patterns of alpha diversity, beta diversity, community composition and community structuring of vascular plants, spiders, insects, and springtails along elevation gradients distributed along the Swedish mountains (Chapter I-III). I also quantified the relative importance of abiotic and biotic environmental conditions for spider diversity (IV), and finally I evaluated if elevational variation in phylogenetic and phenotypic dispersion within vascular plant and spider communities corresponded with an increased environmental regulation at higher elevations (V). Alpha diversity of all organism groups generally declined with elevation. However, while there were geographic differences in these patterns for vascular plants (I-II), there were mainly taxonomic differences in the observed patterns among arthropod groups (III). Taxonomic beta diversity of vascular plants did not show any uniform pattern with elevation but differed both among sites and spatial scales (I-II). The structuring of vascular plant, spider and insect communities were all modular along elevation gradients, but this modularity was less prominent for springtails. Spider and insect communities were also nested along the elevation gradients (III). Vegetation and climate conditions had the largest effects on spider diversity, but the relative effects of different environmental conditions varied both among biodiversity dimensions and spatial scales (IV). Vascular plant and spider communities were both phenotypically and phylogenetically under-dispersed, suggesting that communities were regulated by environmental filtering. However, for vascular plants the phylogenetic dispersion increased while the phenotypic dispersion was constant with elevation, whereas for spiders both phenotypic and phylogenetic dispersion decreased with elevation (V). My results suggest that site-specific and scale-dependent processes may partly override the effects of elevational declines in primary productivity on biodiversity. My results also suggest that biodiversity regulation along gradients can vary among different taxonomic groups and highlight the need to quantify multiple diversity dimensions.
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| 5. |
- 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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| 6. |
- 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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| 7. |
- Pečnerová, Patrícia, et al.
(författare)
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Population genomics of the muskox' resilience in the near absence of genetic variation
- 2024
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Ingår i: Molecular Ecology. - 0962-1083 .- 1365-294X. ; 33:2
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Tidskriftsartikel (refereegranskat)abstract
- Genomic studies of species threatened by extinction are providing crucial information about evolutionary mechanisms and genetic consequences of population declines and bottlenecks. However, to understand how species avoid the extinction vortex, insights can be drawn by studying species that thrive despite past declines. Here, we studied the population genomics of the muskox (Ovibos moschatus), an Ice Age relict that was at the brink of extinction for thousands of years at the end of the Pleistocene yet appears to be thriving today. We analysed 108 whole genomes, including present-day individuals representing the current native range of both muskox subspecies, the white-faced and the barren-ground muskox (O. moschatus wardi and O. moschatus moschatus) and a ~21,000-year-old ancient individual from Siberia. We found that the muskox' demographic history was profoundly shaped by past climate changes and post-glacial re-colonizations. In particular, the white-faced muskox has the lowest genome-wide heterozygosity recorded in an ungulate. Yet, there is no evidence of inbreeding depression in native muskox populations. We hypothesize that this can be explained by the effect of long-term gradual population declines that allowed for purging of strongly deleterious mutations. This study provides insights into how species with a history of population bottlenecks, small population sizes and low genetic diversity survive against all odds.
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