Dynamics of 35 trace elements throughout plant organs in the subalpine broad leaf evergreen shrub Rhododendron ferrugineum

摘要

Increased atmospheric deposition and climate change might affect soil biogeochemical processes and release potentially toxic trace elements in the soil solution. The dynamics and the distribution among plant organs of many trace elements are nevertheless still poorly documented, especially in evergreen species. Here,we measured the concentration of 35 trace elements in roots, stems, as well as in current, 1 yr-old and 2 yr-old leaves (respectively L0, L1 and L2) of the subalpine evergreen shrub Rhododendron ferrugineum. In every plant compartment, concentrations decreased with increasing atomic number. Based on a PCA analysis and the distribution of elements among the different plant compartments at least two groups of elements could be distinguished: i) elements with a high retention factor (RF) in the root compartment and accumulating in leaves with leaf aging, resulting in concentrations decreasing in the order Roots Stems > L2 > L1 > L0; and ii) elements with a low RF resulting in leaf concentrations higher or close to those in roots and stems. However, in contrast with elements from the first group, the dynamics in the leaf compartment of elements from the second group was erratic, with concentrations increasing, decreasing or remaining constant with leaf aging.