Assessing intraspecific Sphagnum trait variation across ecological scales

Abstract:

Plant functional traits can be used to predict ecosystem function. Despite the global significance of Sphagnum for carbon sequestration, Sphagnum functional traits have yet to be measured at global scales. Here we measure Sphagnum functional traits across Canada for S. fuscum and S. medium – which both have a global distribution – to characterize the intraspecific variability traits related to ecosystem function. Specifically capitulum density, capitulum biomass, stem biomass, and fascicle density were measured. Six 1 m² vegetation plots were established in 12 peatlands across Canada for each species (n=72/species). To capture the ecohydrological setting of each plot the ratio of hummocks to hollows and the percent cover of all vascular species were measured. Site-scale mean annual precipitation, air temperature, and water table depth along with the peatland type and the ecohydrological setting of each plot were used as explanatory variables for the variation in Sphagnum traits. We compared the variance in traits across scales (between individuals in a quadrat, between quadrats within a site, and between sites) to determine the scale dependency of intraspecific trait variability. Variation in Sphagnum functional traits was related to plot-scale ecohydrological setting, and climate.