ABSTRACT

The elemental composition of vegetation is poorly known so we report on the minor and trace element concentrations (~50 elements) in leaves and needles from the dominant species of woody vegetation at locations across Canada. Data are combined with estimates for elements near analytical detection limits, to yield an average composition for temperate climate vegetation, mostly grown on post-Pleistocene glacial soils approximating average continental crust (total 71 elements). Lithophile K, Mg, Ca, Sr, chalcophile Hg, Cu, Zn, Mo and Cd and siderophile Ag, Pd, Ir, and Os with low ionic charges and intermediate effective ionic radii show average vegetation/average continental crust ratios (hereafter vegetation/crust) above 0.1. Environmentally-sensitive, 2+, Cd and Hg are highly water-soluble and enriched in vegetation (2.4 and 1.0 * continental crust, respectively). Other high vegetation/crust ratios (1.0 to ~10) are shown by life-essential, 3+ B, 5+ P and 6+ S which have small ionic radii and thus, high effective ionic potentials. Elements with low ratios (~0.001) include the lithophile 3+ rare earth elements (REE, La to Yb), Al, Sc and Ga, 4+ Ti, U, and Th and 5+ V. However, 4+ Zr and Hf and 5+ Nb and Ta form a low concentration trough (~0.0001 * continental crust) in charge-radius space. These concentration patterns reflect charge and radius control on the solubility of elements in soil water. Assuming the immature soils approach average continental crust, the vegetation/crust ratios reflect the partitioning of elements between soil minerals and water taken up by plants. Organizing the elements from highest (S = 13) to lowest (Hf = 0.00004) ratios, allows normalizing other vegetation-based materials with average vegetation to decipher processes impacting the materials. Two published agrifood data sets for Canadian wines and maple syrups illustrate utility of the average vegetation data set for inferring processes.