Blar i forfatter "Böhner, Hanna"

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    • Changing species dominance patterns of Boreal-Arctic heathlands: evidence of biotic homogenization 

      Bråthen, Kari Anne; Tuomi, Maria Wilhelmina; Kapfer, Jutta; Böhner, Hanna; Maliniemi, Tuija (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-03-29)
      Heathlands are extensive systems often dominated by slow-growing and long-lived woody plants. These systems require longer-term studies to capture if and how they are changing over time. In 2020, we resurveyed species richness and cover of vascular plant communities in 139 heathlands along the coastline of northern Fennoscandia, first surveyed during 1965–1975. The first survey included six ...

    • Environmental drivers of increased ecosystem respiration in a warming tundra 

      Maes, S.L.; Dietrich, J.; Midolo, G.; Schwieger, S.; Kummu, M.; Vandvik, Vigdis; Aerts, R.; Althuizen, Inge; Biasi, C.; Björk, R.G.; Böhner, Hanna; Carbognani, M.; Chiari, G.; Christiansen, Casper Tai; Clemmensen, K.E.; Cooper, Elisabeth J.; Cornelissen, J.H.C.; Elberling, Bo; Faubert, P.; Fetcher, N.; Forte, T.G.W.; Gaudard, Joseph; Gavazov, K.; Guan, Z.; Guðmundsson, J.; Gya, Ragnhild; Hallin, S.; Hansen, Brage Bremset; Haugum, Siri Vatsø; He, J.-S.; Hicks Pries, Pries; Hovenden, M.J.; Jalava, M.; Jónsdóttir, I.S.; Juhanson, J.; Jung, J.Y.; Kaarlejärvi, E.; Kwon, M.J.; Lamprecht, R.E.; Le Moullec, Mathilde; Lee, Hanna; Marushchak, M.E.; Michelsen, A; Munir, T.M.; Myrsky, E.M.; Nielsen, C.S.; Nyberg, M.; Olofsson, J.; Óskarsson, H.; Parker, T.C.; Pedersen, E.P.; Petit Bon, Matteo; Petraglia, A.; Raundrup, K.; Ravn, N.M.R.; Rinnan, R.; Rodenhizer, H.; Ryde, I.; Schmidt, N.M.; Schuur, E.A.G.; Sjögersten, S.; Stark, S.; Strack, M.; Tang, J.; Tolvanen, A.; Töpper, Joachim Paul; Väisänen, M.K.; van Logtestijn, Logtestijn; Voigt, C.; Walz, J.; Weedon, J.T.; Yang, Y.; Ylänne, H.; Björkman, Mats Peter; Sarneel, J.M.; Dorrepaal, E. (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-04-17)
      Arctic and alpine tundra ecosystems are large reservoirs of organic carbon1,2. Climate warming may stimulate ecosystem respiration and release carbon into the atmosphere3,4. The magnitude and persistency of this stimulation and the environmental mechanisms that drive its variation remain uncertain5,6,7. This hampers the accuracy of global land carbon–climate feedback projections7,8. Here we synthesize ...

    • Herbivory and warming have opposing short-term effects on plant-community nutrient levels across high-Arctic tundra habitats 

      Petit Bon, Matteo; Bråthen, Kari Anne; Ravolainen, Virve; Ottaviani, Gianluigi; Böhner, Hanna; Jonsdottir, Ingibjørg (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-05-11)
      Environmental changes can rapidly alter standing biomass in tundra plant communities; yet, to what extent can they modify plant-community nutrient levels? Nutrient levels and their changes can affect biomass production, nutrient cycling rates and nutrient availability to herbivores. We examined how environmental perturbations alter Arctic plant-community leaf nutrient concentrations (percentage of ...

    • Long-term herbivore removal experiments reveal how geese and reindeer shape vegetation and ecosystem CO2-fluxes in high-Arctic tundra 

      Petit Bon, Matteo; Hansen, Brage Bremset; Loonen, M. J. J. E; Petraglia, Alessandro; Bråthen, Kari Anne; Böhner, Hanna; Layton-Matthews, Kate; Beard, Karen H.; Le Moullec, Mathilde; Jonsdottir, Ingibjorg Svala; Van der Wal, René (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-23)
      1. Given the current rates of climate change, with associated shifts in herbivore population densities, understanding the role of different herbivores in ecosystem functioning is critical for predicting ecosystem responses. Here, we examined how migratory geese and resident, non-migratory reindeer—two dominating yet functionally contrasting herbivores—control vegetation and ecosystem processes in ...

    • One leaf for all: Chemical traits of single leaves measured at the leaf surface using near-infrared reflectance spectroscopy 

      Petit Bon, Matteo; Böhner, Hanna; Kaino, Sissel; Moe, Torunn; Bråthen, Kari Anne (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-10)
      1. The leaf is an essential unit for measures of plant ecological traits. Yet, measures of plant chemical traits are often achieved by merging several leaves, masking potential foliar variation within and among plant individuals. This is also the case with cost‐effective measures derived using near‐infrared reflectance spectroscopy (NIRS). The calibration models developed for converting NIRS spectral ...

    • A semi-automatic workflow to process images from small mammal camera traps 

      Böhner, Hanna; Kleiven, Eivind Flittie; Ims, Rolf Anker; Soininen, Eeva M (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-05)
      Camera traps have become popular for monitoring biodiversity, but the huge amounts of image data that arise from camera trap monitoring represent a challenge and artificial intelligence is increasingly used to automatically classify large image data sets. However, it is still challenging to combine automatic classification with other steps and tools needed for efficient, quality-assured and adaptive ...

    • A versatile, semi-automated image analysis workflow for time-lapse camera trap image classification 

      Celis, Gerardo; Ungar, Peter; Sokolov, Aleksandr; Soininen, Eeva M; Böhner, Hanna; Liu, Desheng; Gilg, Olivier; Fufachev, Ivan; Pokrovskaya, Olga; Ims, Rolf Anker; Zhou, Wenbo; Morris, Dan; Ehrich, Dorothee (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-03-26)
      Camera traps are a powerful, practical, and non-invasive method used widely to monitor animal communities and evaluate management actions. However, camera trap arrays can generate thousands to millions of images that require significant time and effort to review. Computer vision has emerged as a tool to accelerate this image review process. We propose a multi-step, semi-automated workflow which ...