Portrait photo of Sara Hallin

Sara Hallin

Professor,
E-mail
sara.hallin@slu.se
Phone
+4618-673209
My research focuses on the ecology of microbial communities in terrestrial ecosystems, with a special interest in microbes involved in cycling of nitrogen.

Presentation

I address fundamental questions regarding the ecology of microorgansism in soil and rhizosphere, and also do applied research related to agricultural and environmental issues, such as nutrient cycling, greenhouse gas emissions, and nitrogen leaching. Read about the research group in Soil Microbiology

 

Research

Ongoing research projects:

Ecology of microbes involved in nitrogen cycling

  1. Unearthing the terrestrial nitrogen transforming network. Wallenberg Scholar, Knut and Alice Wallenberg Foundation. PI S. Hallin, 2025-2029
  2. Data driven analyses of the nitrogen cycling microbiome for predictions and novel insights on mechanisms of nitrous oxide emissions from terrestrial ecosystems (NTerraData). SciLifeLab & Wallenberg National Program for Data-Driven Life Science (DDLS). PI S. Hallin, 2024-2028
  3. The many faces of nitrate ammonifying bacteria – Unraveling their role in nitrogen retention and loss, and nitrous oxide emissions in terrestrial ecosystems. Swedish Research Council. PI S. Hallin, 2024-2027

Agroecosystems

  1. Retention-irrigation system to reduce negative impacts of climate change in agricultural landscapes (RETAIN). SLF. PI. M. Bieroza, SLU, 2025-2027
  2. The capacity of crops for enhanced carbon allocation to soil in a changing climate - synergies and trade-offs. Swedish Research Council Formas. PI T. Keller, SLU, 2022-2026
  3. Harnessing plant traits to retain nitrogen in the rhizosphere. Swedish Research Council Formas. PI A. Saghaï, SLU, 2022-2025

Arctic and boreal ecosystems

  1. Soil organic matter dynamics in boreal forests – the role of mycorrhizal mycelia and microbial communities. Swedish Research Council. PI F. Fransson, SLU 2025-2028
  2. Year-round climate feedbacks of winter phenological (mis)matches of plants and microbes across the Arctic. Knut and Alice Wallenberg Foundation. PI E. Dorrepaal, Umeå university, Sweden, 2021-2026

Environmental engineering

  1. Bio-inspired Management of Laughing Gas (MaLaGa): Identifying, Enriching, Genetically Optimizing and Implementing N2O Respiring Biocatalysts (N2ORB). Novo Nordisk Foundation. PI B. Smets, Aarhus University 2025-2027
  2. Sulfate removal from mine leachate (SULFREM). Vinnova. PI R. Herbert, Uppsala univerity, 2022-2025
  3. Treatment of low-contaminated soil with biochar produced from organic waste for sustainable resource use and circular economy (BALANCE). PI A. Enell, Swedish Geotechnical Institute SGI, 2022-2025
 

Teaching

Current teaching at the undergraduate level:

  • Soil Biology and biogeochemistry, (MSc level, SLU, 15 hp).  Covers the basis in soil biology and the major biogeochemical cycles.
  • Molecular and microbial ecology, (BSc level, SLU, 15 hp).
  • Sustainable Plant Production - from Molecular to Field Scale (MSc level, SLU, 15 hp). On the basic principles of sustainable production in agriculture.

Publications

Full list of publications in Google Scholar

Selected recent publications

  • Redondo, M.A., Jones, C.M., Legendre, P., Guénard, G., Hallin, S. 2025. Predicting gene distribution in ammonia-oxidizing archaea using phylogenetic signals. ISME Communications, 5:ycaf087
  • Müller, L.J., Alicke, M., Romdhane, S, Pold, G., Jones, C.M., Saghaï, A., Hallin, S. 2025. Resistance and resilience of co-occurring nitrifying microbial guilds 
    to drying and rewetting stress. Soil Biology and Biochemistry, 208:109846
  • Saghaï, A., Hallin, S. 2024. Diversity and ecology of NrfA-dependent nitrate-ammonifying microorganisms. Trends in Microbiology, 32:602-613
  • Pold, G., Bonilla-Rosso, G., Saghaï, A., Strous, M., Jones, C.M., Hallin, S. 2024. Phylogenetics and environmental distribution of nitric oxide forming nitrite reductases reveals their distinct functional and ecological roles. ISME Communications, 4:ycae020
  • Qui, Y., Zhang, Y., Zhang, K., Xu, X., Zhao, Y., Bai, T., Zhao, Y., Wang, H., Sheng, X., Bloszies, S., Gillespie, C.J., He, T., Wang, Y., Chen, H., Guo, L., Song, H., Wang, Y., Woodley, A., Guo, J., Cheng., L., Bai, Y., Hallin, S., Firestone, M.K., Hu, S. 2024. Intermediate soil acidification induces highest nitrous oxide emissions. Nature Communications, 15:2695
  • Saghaï, A, Pold, G, Jones, CM, Hallin, S. 2023. Phyloecology of nitrate ammonifiers and their importance relative todenitrifiers in global terrestrial biomes. Nature Communications, 14:8249
  • Jones, C.M., Putz, M., Emmerich, M., Hallin, S. 2022. Reactive nitrogen restructures and weakens microbial controls of soil N2O emissions. Communications Biology, 5:273
  • Giovanni Tamburini, G., Bommarco, R., Wanger, T.C., Kremen, C., van der Heijden, M.G.A., Liebman, M. and Hallin, S. 2020. Agricultural diversification supports multiple ecosystem services without compromising yields. Science Advances 6:eaba1715