Factors controlling Mn and Zn contents in leaves of silver and downy birch in acidified soils of Central Europe and Norway.

In Central European mountain forests, foliar element concentrations (FECs) of manganese (Mn) in silver birch (Betula pendula Roth) are occasionally approximately 5000 mg kg and can represent stress for these plants. Factors controlling the Mn FECs in silver birch in Central Europe and downy birch (Betula pubescens Ehrh.) in Norway have not yet been fully deciphered.

Mobilisation of Cd, Mn, and Zn in floodplains by action of plants and its consequences for spreading historical contamination and fluvial geochemistry.

Cadmium, Mn, and Zn are mobilised by plants commonly growing in floodplains, most notably willows (Salix) and alder (Alnus). These plants accumulate unwanted elements (Cd) or excessive element concentrations (Mn, Zn) in their foliage, thus introducing them into the food web and enriching them in floodplain surface by litterfall. In floodplain of the Litavka River in Czechia, contaminated by historical mining activities, up to 100 mg kg Cd and up to several thousand mg kg Mn and Zn are present in willow leaves in autumn, probably close maxima for sustainable plant growth.

Uptake of Cd, Pb, U, and Zn by plants in floodplain pollution hotspots contributes to secondary contamination.

Willows, woody plants of genus Salix common in floodplains of temperate regions, act as plant pumps and translocate the Cd and Zn in the soil profiles of uncontaminated and weakly contaminated floodplains from the sediment bulk to the top strata. We suggest this process occurs because the Cd and Zn concentrations in willow leaves exceed those in the sediments. Senescing foliage of plant species common in floodplains can increase the Cd and Zn ratios as compared to other elements (Pb and common 'lithogenic elements' such as Al) in the top strata of all floodplains, including those that have been severely contaminated.