How the soil chemical composition is affected by seven tree species planted at a contaminated and remediated site

Abstract

Trees modify the physico-chemical and biological properties of the soil underneath. Here we present results for seven tree species planted at a site that was contaminated by a mine spill-after which soil was cleaned up and remediated-and later was afforested. We studied the chemical composition (24 elements) in five ecosystem compartments (leaves, forest floor, roots, topsoil and deep soil). The variation in chemical concentration was highest at the level of canopy leaves and lowest at deep soil. The identity of tree species significantly affected the composition of all elements in the canopies but none in the deep soil underneath. Although the observed tree effects on topsoil chemistry were weak, the footprint is expected to be reinforced with age of the plantation, contributing to the phytostabilization of contaminating elements and to the carbon sequestration.