Fig. 2. Partitioning of Cd, Cu, and Zn in the calcareous and acidic soils before and after Salix viminalis and Thlaspi caerulescens growth. Pool 2 was not extracted in the acidic soil because carbonates were not found in this soil. Pool 1, exchangeable (NaNO₃); Pool 2, carbonate (HOAc); Pool 3, organic matter (Na₄P₂O₇); Pool 4, manganese oxides (NH₂OH x HCl); Pool 5, iron oxides (NH₂OH x HCl and HOAc); Pool 6, residual (HNO₃, HF, and HClO₄). The symbol * indicates a difference from the control at the 0.05 probability level.