Comparative foliage and twig chemistry of co-occurring Myrica gale and Chamaedaphne calyculata

Abstract

The deciduous N-fixing shrub Myrica gale L. and the evergreen sclerophyllous shrub Chamaedaphne calyculata (L.) Moench sometimes intermingle in small patches in boreal peatlands. The mineral element composition of adjacent plants and plant parts may differ owing to the distinctive morphology and physiology of each species. We compared the elemental composition and allocation patterns of Myrica and Chamaedaphne co-occurring in 1-m2 plots in a western Adirondack peatland. Current foliage and twigs of each species were analyzed for Al, B, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, Pb, Se, V, and Zn. Fourteen elements differed significantly among tissues. Chamaedaphne foliage was highest in Al, Mn, and P, and Chamaedaphne twigs were highest in Cu, whereas Myrica foliage was highest in K and Ni, and Myrica twigs were highest in Mo and Zn. Elemental differences were interpreted with respect to possible physiological roles in each species. Additionally, a multivariate discriminant function analysis yielded two canonical variables: (i) a structural – functional component correlated with Al, B, Ca, Cu, Fe, and K that distinguished Myrica from Chamaedaphne, and (ii) a metabolic component correlated with Al, B, Mo, P, and Zn that separated foliage from twigs. Key words: peatland, sclerophylly, nitrogen fixer, tissue chemistry, Chamaedaphne calyculata, Myrica gale.