Niche construction mediates climate effects on recovery of tundra heathlands after extreme event

in 2016, and commercially available peat (Peat)). (DOCX) S1 Table. List of vascular plant species and growth forms registered in extreme event and control plots in 2019 in order of decreasing biomass (g/m2). (DOCX) S2 Table. Anova tables from the linear models showing the effect of the extreme event (EE), continentality index (CI) and their interactions (CIxEE) on the mean values of a) species richness, total biomass, biomass of subordinate species and biomass of E. nigrum alone; b) leaf traits: specific leaf area (SLA), leaf dry matter content (LDMC) and leaf nitro- gen content (LNC), c) seedling length of the vascular plant species used in bioassay, and d) lichen, moss and soil. Significant values are presented in bold. (DOCX) S3 Table. ANOVA table from the linear model showing the effect of the extreme event (EE), continentality index (CI), year, and the interaction of year and continentality index (YearxCI) on the mean seedling count of all species sown in 2011. Only significant interac- tions are presented. Significant values are presented in bold. (DOCX) Acknowledgments We are thankful to Sissel Kaino, Xavier Ancin, Anna-Katharina Pilsbacher, Metha Klock, Mil- drid Svoen and Mikel Moriana Armendariz for help during the field work, and Leidulf Lund for help performing the studies at the phytotron. Author Contributions Conceptualization: Victoria T. Gonza´lez, Bente Lindgård, Rigmor Reiersen, Kari Anne Bråthen. Data curation: Victoria T. Gonza´lez, Bente Lindgård, Rigmor Reiersen, Snorre B. Hagen, Kari Anne Bråthen.

Formal analysis: Victoria T. Gonza´lez, Snorre B. Hagen. Investigation: Victoria T. Gonza´lez, Kari Anne Bråthen. Methodology: Victoria T. Gonza´lez, Rigmor Reiersen, Kari Anne Bråthen. Project administration: Kari Anne Bråthen. Supervision: Kari Anne Bråthen. Validation: Victoria T. Gonza´lez, Kari Anne Bråthen. Visualization: Victoria T. Gonza´lez. Writing – original draft: Victoria T. Gonza´lez. Writing – review & editing: Victoria T. Gonza´lez, Bente Lindgård, Rigmor Reiersen, Snorre B. Hagen, Kari Anne Bråthen. References 1. Vikhamar-Schuler D, Isaksen K, Haugen JE, Tommervik H, Luks B, Schuler TV, et al. Changes in Win- ter Warming Events in the Nordic Arctic Region. J Climate. 2016; 29(17):6223–44. PLOS ONE Niche construction effects on tundra after extreme event PLOS ONE | https://doi.org/10.1371/journal.pone.0245929 February 4, 2021 12 / 14