Element stoichiometry and nutrient limitation in bog plant and lichen species

Abstract Ombrotrophic bogs receive new inputs of elements solely through atmospheric deposition, except for N where are predominantly 2 -fixation, at least in low deposition environments. At various locations across the globe, including Athabasca Oil Sands Region (AOSR) northern Alberta, Canada, element has increased as a result anthropogenic activities. Regional and/or global gradients offer an opportunity to examine questions related nutrient limitation and stoichiometry, i.e., maintenance relatively constant ratios bog lichen/plant tissues despite differing deposition/availability. Using dataset tissue concentrations eight species six AOSR bogs, supplemented with literature data from other sites globally, this synthesis asks: is there evidence stoichiometric homeostasis lichen or plant bogs; if so, do relationships extend globally beyond AOSR, and; provide insight into species? Mean their coefficients variation, ternary NPK CaMgK plots, scaling revealed widespread homeostasis. Stoichiometric generally were unaffected by differences among bogs. sometimes extended but did not. Element diagrams suggested combination N-, P-, K-limitation, both within Regionally high may have shifted some N-limitation prior Industrial Revolution P- K-limitation today.