Luke
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Jukuri

Tervetuloa käyttämään Jukuria, Luonnonvarakeskuksen (Luke) avointa julkaisuarkistoa. Jukurissa on tiedot Luken julkaisutuotannosta. Osa julkaisuista on vapaasti ladattavissa. Luken muodostaneiden tutkimuslaitosten aikaisemmasta julkaisutuotannosta osan tiedot ovat järjestelmässä jo nyt ja kattavuus paranee jatkuvasti.

Kokoelmat

Viimeksi tallennetut

  • Global Change Reshapes Biosynthesis of LC‐PUFA in Northern Lake Food Webs
    Pilecky, Matthias; Vuorio, Kristiina; Rigaud, Cyril; Calderini, Marco; Kahilainen, Kimmo K.; Ruokonen, Timo J.; Kainz, Martin J.; Vesterinen, Jussi; Taipale, Sami J.
    Global change biology : 8 (Wiley-Blackwell, 2026)
    Global change is altering the physico-chemical characteristics of northern lakes through warming, shifting nutrient regimes, and increasing dissolved organic carbon (DOC). These changes are reshaping the trophic structure and nutritional quality of freshwater food webs. To investigate how such environmental gradients influence the production and trophic transfer of long-chain polyunsaturated fatty acids (LC-PUFA), we quantified LC-PUFA biosynthesis in 12 boreal lakes along a trophic gradient. Bayesian models were used to relate biosynthesis to phytoplankton biomass and community composition, while compound-specific stable hydrogen isotopes and fads2 gene expression were applied to distinguish dietary acquisition from endogenous n-3 LC-PUFA synthesis in zooplankton and planktivorous fish. We further extrapolated LC-PUFA biosynthesis across 643 boreal and subarctic lakes covering a~7°C temperature gradient and a 1–160 μg L−1 phosphorus range using long-term phytoplankton monitoring data. Phytoplankton LC-PUFA biosynthesis ranged from 1 to 400 ng g C−1 h−1, of which the edible (< 35 μm) fraction for zooplankton contributed only 45%–74%. Stable isotope and gene-expression analysis indicated that biosynthesis rates exceeding ~100 ng g C−1 h−1 in the edible fraction were required to reduce consumer reliance on endogenous bioconversion to below 10%. Across the 643 lakes, LC-PUFA production exhibited a unimodal relationship with phosphorus, peaking at intermediate nutrient levels; however, only 166 lakes produced sufficient LC-PUFA to meet inferred consumer requirements. Nutrient enrichment, warming, and browning acted synergistically to restructure phytoplankton community composition and constrain LC-PUFA availability. Eutrophication and browning promoted LC-PUFA-poor taxa, whereas warming altered biomass distribution and reduced LC-PUFA production within the edible phytoplankton size fraction. Together, these changes intensified a nutritional bottleneck at the base of aquatic food webs. Our findings demonstrate that global change profoundly modifies phytoplankton community structure, LC-PUFA production, and trophic transfer efficiency, which may generate cascading effects on the functioning and productivity of northern freshwater ecosystems.
  • Inland and early marine migration patterns of silver european eels Anguilla anguilla (Linnaeus, 1758)
    Dainys, Justas; Frankowski, Jens; Sjöberg, Niklas; Kristensen, Martin Lykke; Koed, Anders; Helminen, Jani
    Estuarine coastal and shelf science (Academic Press, 2026)
  • Kasvutunnelimuovien valonläpäisyominaisuuksien arviointi spektrimittausten avulla
    Kotilainen, Titta; Rikala, Kati
    Luke Tietokortti (Luonnonvarakeskus, 2026)
    Marjojen tuotanto kasvutunneleissa lisääntyy tasaisesti Suomessa, sillä katettu tunneli suojaa sään vaihteluilta, pidentää satokautta, tehostaa tuotantopanosten käyttöä ja lisää satoa pinta-alaa kohden, mikä pienentää myös tuotannon ympäristöjalanjälkeä. Kasvutunnelit tehostavat lisäksi biologisen torjunnan käyttöä ja kouruviljely vähentää maalevintäisten tautien leviämisriskiä. Viimeisen kymmenen vuoden aikana kotimaisen mansikan tunneliviljelyala on kasvanut voimakkaasti ja myös vadelman tunneliviljelyala on kaksinkertaistunut. Vuonna 2025 tunnelimansikkaa oli viljelyssä 89 hehtaaria ja tunnelivadelmaa 33 hehtaaria.
  • On spatial point processes with composition-valued marks
    Eckardt, Matthias; Myllymäki, Mari; Greven, Sonja
    International statistical review (Wiley-Blackwell, 2025)
    Habitat restoration may protect brown trout (Salmo trutta) populations from loss of genetic diversity by increasing environmental carrying capacity and, consequently, population size. However, the accompanying release of hatchery-reared fish may threaten the genetic integrity of native populations through introgression. We monitored the genetic composition of four native brown trout populations using 16 putatively neutral microsatellite loci in small boreal streams subjected to restoration measures and the release of hatchery-reared brown trout. Sampling was conducted before restoration, during the expected recovery phase, and after recovery. Analysis of population composition over the 19-year study period indicated interbreeding between hatchery and wild fish shortly after the releases, but the most recent samples predominantly represented native, presumably resident genotypes. Restoration treatments had no detectable effects on the genetic diversity of the small study populations. Our results add to the evidence suggesting that stocking with non-native fish is ineffective in enhancing wild populations.
  • Modelling covariance structures in determinantal point processes for spatio-temporal interactions
    Vafaei, Nafiseh; Myllymäki, Mari; Ghorbani, Mohammad
    Communications in statistics: theory and methods : 15 (Taylor & Francis, 2026)
    Habitat restoration may protect brown trout (Salmo trutta) populations from loss of genetic diversity by increasing environmental carrying capacity and, consequently, population size. However, the accompanying release of hatchery-reared fish may threaten the genetic integrity of native populations through introgression. We monitored the genetic composition of four native brown trout populations using 16 putatively neutral microsatellite loci in small boreal streams subjected to restoration measures and the release of hatchery-reared brown trout. Sampling was conducted before restoration, during the expected recovery phase, and after recovery. Analysis of population composition over the 19-year study period indicated interbreeding between hatchery and wild fish shortly after the releases, but the most recent samples predominantly represented native, presumably resident genotypes. Restoration treatments had no detectable effects on the genetic diversity of the small study populations. Our results add to the evidence suggesting that stocking with non-native fish is ineffective in enhancing wild populations.