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• Kristiansen, Silje Marie; Leinaas, Hans Petter; Gestel, Cornelis A.M. van & Borgå, Katrine (2024). Thermal adaptation affects the temperature-dependent toxicity of the insecticide imidacloprid to soil invertebrates. Science of the Total Environment. ISSN 0048-9697. 944. doi: 10.1016/j.scitotenv.2024.173845. Fulltekst i vitenarkiv Vis sammendrag

  Terrestrial ectotherms are vulnerable to climate change since their biological rates depend on the ambient temperature. As temperature may interact with toxicant exposure, climate change may cause unpredictable responses to toxic stress. A population's thermal adaptation will impact its response to temperature change, but also to interactive effects from temperature and toxicants, but these effects are still not fully understood. Here, we assessed the combined effects of exposure to the insecticide imidacloprid across the temperatures 10–25 °C of two populations of the Collembola Hypogastrura viatica (Tullberg, 1872), by determining their responses in multiple life history traits. The con-specific populations differ considerably in thermal adaptations; one (arctic) is a temperature generalist, while the other (temperate) is a warm-adapted specialist. For both populations, the sub-lethal concentrations of imidacloprid became lethal with increasing temperature. Although the thermal maximum is higher for the warm-adapted population, the reduction in survival was stronger. Growth was reduced by imidacloprid in a temperature-dependent manner, but only at the adult life stage. The decrease in adult body size combined with the absence of an effect on the age at first reproduction suggests a selection on the timing of maturation. Egg production was reduced by imidacloprid in both populations, but the negative effect was only dependent on temperature in the warm-adapted population, with no effect at 10 °C, and decreases of 41 % at 15 °C, and 74 % at 20 °C. For several key traits, the population best adapted to utilize high temperatures was also the most sensitive to toxic stress at higher temperatures. It could be that by allocating more energy to faster growth, development, and reproduction at higher temperatures, the population had less energy for maintenance, making it more sensitive to toxic stress. Our findings demonstrate the need to take into account a population's thermal adaptation when assessing the interactive effects between temperature and other stressors.

• Silva, Andreia Sofia Jorge; Kristiansen, Silje Marie; Sengupta, Sagnik; Gestel, Cornelis A. M. van; Leinaas, Hans Petter & Borgå, Katrine (2023). Using dietary exposure to determine sub-lethal effects from imidacloprid in two springtail (Collembola) species. Ecotoxicology. ISSN 0963-9292. 32, s. 1209–1220. doi: 10.1007/s10646-023-02715-x. Fulltekst i vitenarkiv Vis sammendrag

  Abstract Standard toxicity tests expose springtails (Collembola) through soil, while dietary exposure tests with animals visible on a surface are less commonly applied. We refined a method for dietary chemical exposure for two widely distributed and abundant Collembola species: Folsomia quadrioculata and Hypogastrura viatica as existing methods were sub-optimal. Newly hatched Collembola were offered bark with a natural layer of Cyanobacteria that was either moistened with a solution of the neonicotinoid insecticide imidacloprid using a micropipette or soaked in the solution overnight. The first method was superior in producing a measured concentration close to the nominal (0.21 and 0.13 mg/kg dry bark, respectively), and resulting in sub-lethal effects as expected. The adult body size was reduced by 8% for both species, but egg production only in H. viatica . Contrastingly, soaked bark resulted in a measured concentration of 8 mg/kg dry bark, causing high mortality and no egg production in either species. Next, we identified the sub-lethal concentration-range by moistening the bark to expose H. viatica to 0, 0.01, 0.04, 0.13, 0.43 and 1.2 mg imidacloprid/kg dry bark. Only the highest concentration affected survival, causing a mortality of 77%. Imidacloprid reduced moulting rate and the body size at first reproduction. The age at first reproduction appeared delayed as some replicates did not reproduce within the experiment duration. The method of moistened bark for dietary exposure proved optimal to continuously study life history traits, such as growth and reproductive outcomes, which are important to understand effects on key events crucial for population viability and growth.

• Pedersen, Åshild Ønvik; Convey, P.; Newsham, Kevin K.; Mosbacher, Jesper Bruun; Fuglei, Eva & Ravolainen, Virve [Vis alle 47 forfattere av denne artikkelen] (2022). Five decades of terrestrial and freshwater research at Ny-Ålesund, Svalbard. Polar Research. ISSN 0800-0395. 41. doi: 10.33265/polar.v41.6310. Fulltekst i vitenarkiv Vis sammendrag

  For more than five decades, research has been conducted at Ny-Ålesund, in Svalbard, Norway, to understand the structure and functioning of High-Arctic ecosystems and the profound impacts on them of environmental change. Terrestrial, freshwater, glacial and marine ecosystems are accessible year-round from Ny-Ålesund, providing unique opportunities for interdisciplinary observational and experimental studies along physical, chemical, hydrological and climatic gradients. Here, we synthesize terrestrial and freshwater research at Ny-Ålesund and review current knowledge of biodiversity patterns, species population dynamics and interactions, ecosystem processes, biogeochemical cycles and anthropogenic impacts. There is now strong evidence of past and ongoing biotic changes caused by climate change, including negative effects on populations of many taxa and impacts of rain-on-snow events across multiple trophic levels. While species-level characteristics and responses are well understood for macro-organisms, major knowledge gaps exist for microbes, invertebrates and ecosystem-level processes. In order to fill current knowledge gaps, we recommend (1) maintaining monitoring efforts, while establishing a long-term ecosystem-based monitoring programme; (2) gaining a mechanistic understanding of environmental change impacts on processes and linkages in food webs; (3) identifying trophic interactions and cascades across ecosystems; and (4) integrating long-term data on microbial, invertebrate and freshwater communities, along with measurements of carbon and nutrient fluxes among soils, atmosphere, freshwaters and the marine environment. The synthesis here shows that the Ny-Ålesund study system has the characteristics needed to fill these gaps in knowledge, thereby enhancing our understanding of High-Arctic ecosystems and their responses to environmental variability and change.

• Kristiansen, Silje Marie; Borgå, Katrine; Rundberget, Jan Thomas & Leinaas, Hans Petter (2021). Effects on Life-History Traits of Hypogastrura viatica (Collembola) Exposed to Imidacloprid Through Soil or Diet. Environmental Toxicology and Chemistry. ISSN 0730-7268. 40(11), s. 3111–3122. doi: 10.1002/etc.5187. Fulltekst i vitenarkiv Vis sammendrag

  Collembola (springtails) are important members of soil communities worldwide by contributing to degradation of organic matter. In nature, Collembola might be exposed to the neonicotinoid insecticide imidacloprid, which is fairly persistent in soil. We exposed the widespread Hypogastrura viatica to imidacloprid through soil or food and monitored the animals during exposure and a post exposure period. We recorded effects on life-history traits affecting individual fitness, that is, mortality, behavioral activity, several reproduction traits, and molting frequency. Exposure through soil led to a concentration-dependent mortality, while the mortality from dietary exposure possibly reflected reduced feeding activity. The body burden of imidacloprid in the Collembola did not differ between treatments. We found no sign of recovery in behavioral activity following exposure in either experiment. The egg production of H. viatica was not significantly affected by imidacloprid at 0.01 mg/kg dry soil but showed a tendency to reduce number of eggs per batch and reduced hatching success. At higher concentrations, reproduction was close to, or completely, stopped. The molting frequency decreased during exposure, while in the post exposure period, we saw milder effects at the highest concentrations, suggesting elimination through molting or reduced toxic response as a result of reduced feeding activity. Overall, H. viatica was more sensitive to imidacloprid than previously studied Collembola, which highlights the importance of considering species sensitivities when risk-assessing soil environments.

• Kristiansen, Silje Marie; Leinaas, Hans Petter; Herzke, Dorte; Hylland, Ketil; Gabrielsen, Geir W. & Harju, Mikael [Vis alle 7 forfattere av denne artikkelen] (2019). Seabird-transported contaminants are reflected in the Arctic tundra, but not in its soil-dwelling springtails (Collembola). Environmental Science and Technology. ISSN 0013-936X. 53(21), s. 12835–12845. doi: 10.1021/acs.est.9b05316. Fulltekst i vitenarkiv Vis sammendrag

  Arctic-breeding seabirds contain high levels of many anthropogenic contaminants, which they deposit through guano to the tundra near their colonies. Nutrient-rich soil in vicinity to seabird colonies are favorable habitats for soil invertebrates, such as springtails (Collembola), which may result in exposure to seabird-derived contaminants. We quantified a wide range of lipid-soluble and protein-associated environmental contaminants in two springtail species (Megaphorura arctica and Hypogastrura viatica) and their respective habitats (soil/moss) collected underneath seabird cliffs. Although springtails are commonly used in laboratory toxicity tests, this is the first study to measure concentrations of persistent organic pollutants (POPs) and mercury (Hg) in springtails from the field, and to study biotransportation of contaminants by seabirds to soil fauna. We categorized the sites a priori as of low, medium, or high seabird influence, based on the seabird abundance and species composition. This ranking was reflected in increasing δ15N values in soil/moss and springtails with increasing seabird influence. We found clear indications of seabirds impacting the terrestrial soil environments with organic contaminants, and that concentrations were higher in soil and moss close to the bird cliff, compared to farther away. However, we did not find a relationship between contaminant concentration in springtails and the concentrations in soil/moss, or with level of seabird influence. Our study indicates a low uptake of contaminants in the soil fauna, despite seabird-derived contamination of their habitat.

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• Kristiansen, Silje Marie; Leinaas, Hans Petter; Herzke, Dorte; Hylland, Ketil; Gabrielsen, Geir W. & Harju, Mikael [Vis alle 7 forfattere av denne artikkelen] (2019). The Arctic tundra and its soil-dwelling springtails (Collembola) reflect nitrogen and contaminants biotransported by seabirds. Fulltekst i vitenarkiv
• Hylland, Ketil; Skei, Bjørn Borge; Gilmore, Erik Howard; Fredriksen, Lene; Keilen, Ellen Kristine & Kristiansen, Silje Marie [Vis alle 11 forfattere av denne artikkelen] (2018). Er det en sammenheng mellom miljøgift-eksponering og DNA-skade i spretthaler, hoppekreps, blåskjell, fisk, fugl og isbjørn? Fulltekst i vitenarkiv

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