title: The resilience and functional role of moss in boreal and arctic ecosystems.
abstract: Mosses in northern ecosystems are ubiquitous components of plant communities, and strongly influence nutrient, carbon and water cycling. We use literature review, synthesis and model simulations to explore the role of mosses in ecological stability and resilience. Moss community responses to disturbance showed all possible responses (increases, decreases, no change) within most disturbance categories. Simulations from two process-based models suggest that northern ecosystems would need to experience extreme perturbation before mosses were eliminated. But simulations with two other models suggest that loss of moss will reduce soil carbon accumulation primarily by influencing decomposition rates and soil nitrogen availability. It seems clear that mosses need to be incorporated into models as one or more plant functional types, but more empirical work is needed to determine how to best aggregate species. We highlight several issues that have not been adequately explored in moss communities, such as functional redundancy and singularity, relationships between response and effect traits, and parameter vs conceptual uncertainty in models. Mosses play an important role in several ecosystem processes that play out over centuries - permafrost formation and thaw, peat accumulation, development of microtopography - and there is a need for studies that increase our understanding of slow, long-term dynamical processes.
authors.affiliation: Department of Integrative Biology, University of Guelph, Guelph ON N1G 1G2, Canada.
authors.forename: M R
authors.initials: MR
authors.lastname: Turetsky
authors.affiliation: Joint Global Change Research Institute, DOE Pacific Northwest National Laboratory, 5825 University Research Ct, College Park, MD, USA.
authors.forename: B
authors.initials: B
authors.lastname: Bond-Lamberty
authors.affiliation: University of Alaska Fairbanks, Institute of Arctic Biology, Fairbanks, AK 99775, USA.
authors.forename: E
authors.initials: E
authors.lastname: Euskirchen
authors.affiliation: Institute for the Study of Earth, Oceans, and Space, and Department of Earth Sciences, University of New Hampshire, Durham, NH 03824, USA.|Département de Géographie, Université de Montréal, Montréal QC H2V 2B8, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Talbot
authors.affiliation: Institute for the Study of Earth, Oceans, and Space, and Department of Earth Sciences, University of New Hampshire, Durham, NH 03824, USA.
authors.forename: S
authors.initials: S
authors.lastname: Frolking
authors.affiliation: US Geological Survey, Alaska Cooperative Fish and Wildlife Research Unit, University of Alaska Fairbanks, Fairbanks, AK 99775, USA.
authors.forename: A D
authors.initials: AD
authors.lastname: McGuire
authors.affiliation: School of Forest Sciences, University of Eastern Finland, PO Box 111, FIN-80101 Joensuu, Finland.
authors.forename: E-S
authors.initials: ES
authors.lastname: Tuittila
mesh_terms: D000222:Adaptation, Physiological; D000531:Altitude; D001110:Arctic Regions; D044002:Bryophyta / Q000502:physiology*; D057231:Climate Change; D017753:Ecosystem