Shallow soils are warmer under trees and tall shrubs across Arctic and Boreal ecosystems

• Published in: Environmental Research Letters
• Main Authors: Kropp, Heather, Loranty, Michael M, Natali, Susan M, Kholodov, Alexander L, Rocha, Adrian V, Myers-Smith, Isla, Abbot, Benjamin W, Abermann, Jakob, Blanc-Betes, Elena, Blok, Daan, Blume-Werry, Gesche, Boike, Julia, Breen, Amy L, Cahoon, Sean M P, Christiansen, Casper T, Douglas, Thomas A, Epstein, Howard E, Frost, Gerald V, Goeckede, Mathias, Høye, Toke T, Mamet, Steven D, O’Donnell, Jonathan A, Olefeldt, David, Phoenix, Gareth K, Salmon, Verity G, Sannel, A Britta K, Smith, Sharon L, Sonnentag, Oliver, Vaughn, Lydia Smith, Williams, Mathew, Elberling, Bo, Gough, Laura, Hjort, Jan, Lafleur, Peter M, Euskirchen, Eugenie S, Heijmans, Monique MPD, Humphreys, Elyn R, Iwata, Hiroki, Jones, Benjamin M, Jorgenson, M Torre, Grünberg, Inge, Kim, Yongwon, Laundre, James, Mauritz, Marguerite, Michelsen, Anders, Schaepman-Strub, Gabriela, Tape, Ken D, Ueyama, Masahito, Lee, Bang-Yong, Langley, Kirsty
• Other Authors: Danish National Research Foundation, Arctic Challenge for Sustainability, Imperial Oil, Ltd, AMAX Northwest Mining, Co, Swiss National Science Foundation, Research Network for Geosciences in Berlin and Potsdam, United States Geological Survey, Strategic Environmental Research and Development Program, Northern Scientific Training Program, Greenland Ecosystem Monitoring Programme: ClimateBasis, Natural Sciences and Engineering Research Council of Canada, Engineer Research and Development Center Army Direct, University of Alberta, University of Alberta Northern Research Awards, URPP Global Change and Biodiversity, University of Zurich, UT-Battelle, LLC, Churchill Northern Studies Centre, Wapusk National Park, National Research Foundation of Korea, Academy of Finland, The Garfield Weston Foundation, Earthwatch International, Office of Biological and Environmental Research in the DOE Office of Science, UK Natural Environment Research Council, National Science Foundation
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: IOP Publishing 2020
• Subjects: Arctic; permafrost; Tundra
• Online Access: http://dx.doi.org/10.1088/1748-9326/abc994; https://iopscience.iop.org/article/10.1088/1748-9326/abc994; https://iopscience.iop.org/article/10.1088/1748-9326/abc994/pdf; https://iopscience.iop.org/article/10.1088/1748-9326/abc994/ampdf

Abstract Soils are warming as air temperatures rise across the Arctic and Boreal region concurrent with the expansion of tall-statured shrubs and trees in the tundra. Changes in vegetation structure and function are expected to alter soil thermal regimes, thereby modifying climate feedbacks related to permafrost thaw and carbon cycling. However, current understanding of vegetation impacts on soil temperature is limited to local or regional scales and lacks the generality necessary to predict soil warming and permafrost stability on a pan-Arctic scale. Here we synthesize shallow soil and air temperature observations with broad spatial and temporal coverage collected across 106 sites representing nine different vegetation types in the permafrost region. We showed ecosystems with tall-statured shrubs and trees (>40 cm) have warmer shallow soils than those with short-statured tundra vegetation when normalized to a constant air temperature. In tree and tall shrub vegetation types, cooler temperatures in the warm season do not lead to cooler mean annual soil temperature indicating that ground thermal regimes in the cold-season rather than the warm-season are most critical for predicting soil warming in ecosystems underlain by permafrost. Our results suggest that the expansion of tall shrubs and trees into tundra regions can amplify shallow soil warming, and could increase the potential for increased seasonal thaw depth and increase soil carbon cycling rates and lead to increased carbon dioxide loss and further permafrost thaw.