Piippa Wäli

Piippa Wäli, Post doctoral researcher, PhD

Department of Ecology, University of Oulu, Finland

Contact: piippa.wali (at) oulu.fi

Visiting specialist at Natural Resources Institute Finland

Research interests:

  • Arctic-alpine plant ecology

  • Microfungi

  • Symbiosis

  • Mutualism

  • Plant pathogens

  • Grass endophytes (Epichloë spp.)

  • Ecology of ergot (Claviceps purpurae)

  • Microfungal associates of Empetrum nigrum ssp. hermaphroditum

  • Changes in plant and fungal communities due to moth outbreaks in mountain birch forests

  • Evolution of symbiosis

  • Herbivores

  • Conservation of rare arctic-alpine plant species

  • Bioremediation by plants and their symbiotic microbes

  • Metals and microbes

Publications:

    • Sandén, H., Mayer, M., Stark, S. Sandén T, Nilsson L.O., Jepsen, J.U., Wäli P.R. Rewald B. (2020) Moth outbreaks reduce decomposition in subarctic forest soils. Ecosystems 23: 151. https://doi.org/10.1007/s10021-019-00394-6
    • Middleton M, Torppa J, Wäli PR, Sutinen R (2018) Biogeochemical anomaly response of circumboreal shrubs and juniper to the Juomasuo hydrothermal Au-Co deposit in northern Finland. (Applied Geochemistry 98: 141-151. https://doi.org/10.1016/j.apgeochem.2018.09.006.)
    • Koivusaari P, Pohjanen J, Wäli PR, Ahonen SHK, Saravesi K, Markkola AM, Haapala K, Suokas M, Koskimäki JJ, Tejesvi MV, Pirttilä AM (2018) Different endophyte communities colonize buds of sprouts compared with mature trees of mountain birch recovered from moth herbivory. (Tree Physiology, 38: 1437–1444. https://doi.org/10.1093/treephys/tpy012)
    • Lappalainen K, Vogeler N, Kärkkäinen J, Dong Y, Niemelä M, Rusanen A, Ruotsalainen AL, Wäli P, Markkola A, Lassi U (2018) Microwave-assisted conversion of novel biomass materials into levulinic acid. (Biomass Conversion and Biorefinery 8: 965–970. https://doi.org/10.1007/s13399-018-0334-6)
    • Laitinen RK, Hellström KO, Wäli PR (2016): Context-dependent outcomes of subarctic grass-endophyte symbiosis. (Fungal Ecology 23:66-74. http://dx.doi.org/10.1016/j.funeco.2016.06.004.)
    • Kauppinen M, Saikkonen K, Helander M, Pirttilä AM, Wäli PR (2016): Epichloë grass endophytes in sustainable agriculture. Nature Plants 2: doi:10.1038/nplants.2015.224.
    • Saravesi K, Aikio S, Wäli PR, Ruotsalainen AL, Kaukonen M, Huusko K, Brown SP, Jumpponen A, Tuomi J, Markkola A (2015): (2015). Moth Outbreaks Alter Root-Associated Fungal Communities in Subarctic Mountain Birch Forests. (Microbial ecology 69(4): 788-797. DOI 10.1007/s00248-015-0577-8)
    • Gundel PE, Garibaldi LA, Wäli PR, Helander M, Dirihan S, Saikkonen K (2014): Fungal endophyte mediated occurrence of seminiferous and pseudoviviparous panicles in Festuca rubra. Fungal Diversity 66:69–76, DOI 10.1007/s13225-014-0290-9.
    • Biuw M, Jepsen JU, Cohen J, Ahonen SH, Tejesvi M, Aikio S, Wäli PR, Vindstad OPL, Markkola A, Niemelä P, Ims RA (2014): Long-term Impacts of Contrasting Management of Large Ungulates in the Arctic Tundra-Forest Ecotone: Ecosystem Structure and Climate Feedback. (Ecosystems, 17: 890-905. DOI:10.1007/s10021-014-9767-3).
    • Kauppinen M, Raveala K, Wäli PR, Ruotsalainen AL (2014): Contrasting preferences of arbuscular mycorrhizal and dark septate fungi colonizing boreal and subarctic Avenella flexuosa. (Mycorrhiza 24(3): 171-177. DOI:10.1007/s00572-013-0526-7)
    • Wäli PP, Wäli PR, Saikkonen K, Tuomi J (2013): Is the pathogenic ergot fungus a conditional defensive mutualist for its host grass? PLoS ONE 8(7): e69249. doi:10.1371/journal.pone.0069249
    • Kaukonen M, Ruotsalainen AL, Wäli PR, Männistö MK, Setälä H, Saravesi K, Huusko K, and Markkola AM (2013) Moth herbivory enhances resource turnover in subarctic mountain birch forests? (Ecology, 94:267–272)
    • P. R. Wäli, M. Helander, K. Saikkonen (2011): Manipulation of Epichloë/Neotyphodium-endophyte infection in pooid grasses. In A.M. Pirttilä, S. Sorvari (eds.) Prospects and Applications for Plant-Associated Microbes. A Laboratory Manual, Part B: Fungi. BioBien Innovations, Finland.
    • Jensen JB, González VT, Guevara TU, Bhuvaneswari TV, Wäli PR, Tejesvi MV, Pirttilä AM, Bazely D, Vicari M, Bråthen KA (2011) Kit for detection of fungal endophytes of grasses yields inconsistent results. (Methods in Ecology and Evolution 2:197-201)
    • Saikkonen K, Wäli, PR, Helander M (2010) Genetic compatibility determines endophyte-grass combinations. PloS One 5: e11395
    • Pirttilä AM, Wäli, PR (2009) Conifer endophytes. In: White JF, Torres M (eds.) Defensive Mutualism in Microbial Symbiosis. Taylor Francis Group Publishers.
    • Wäli, PR, Helander, M, Saloniemi, I, Ahlholm, J, Saikkonen, K (2009) Variable effects of endophytic fungus on seedling establishment of fine fescues. (Oecologia 159:49-57)
    • Wäli, PR, Helander, M, Nissinen, O, Lehtonen, P. and Saikkonen, K. (2008) Endophyte infection, nutrient status of the soil and duration of snow cover influence the performance of meadow fescue in sub-arctic conditions. (Grass and Forage Science 63:324–330).
    • Wäli, PR, Ahlholm, J, Helander, M, Saikkonen, K (2007) Occurrence and genetic structure of the systemic grass endophyte Epichloë festucae in fine fescue populations. (Microbial Ecology 53:20-29)
    • Helander, M, Wäli, PR, Kuuluvainen, T, Saikkonen, K (2006) Birch leaf endophytes in managed and natural boreal forests. Canadian Journal of Forest Research 36:3239-3245.
    • Wäli, PR, Helander, M, Nissinen, O, Saikkonen, K (2006) Susceptibility of endophyte-infected grasses to winter pathogens (snow molds). (Canadian Journal of Botany 84:1043-1051)
    • Saikkonen, K, Wäli, P, Helander, M. and Faeth, SH (2004) Evolution of endophyte-plant symbioses. (Trends in Plant Science 9:275-280)
    • Ahlholm, J, Helander, M, Lehtimäki, S, Wäli, P and Saikkonen, K (2002) Vertically transmitted fungal endophytes: different responses of host-parasite systems to environmental condition. (OIKOS 99:173-183).