Photosynthetic Efficiency of Four Woody Species Growing on Fly Ash Deposits of a Serbian 'Nikola Tesla - A' Thermoelectric Plant

Abstract

Photosynthetic efficiency and damage symptoms of Tamarix tetrandra Pallas, Populus alba L., Robinia pseudoacacia L. (planted), and Amorpha fruticosa L. (naturally colonized) were studied at two fly ash deposit lagoons of the 'Nikola Tesla - A' power plant (Obrenovac, Serbia), weathered 5 (L1) and 13 years (L2). In early phases of weathering, after 5 years, a reduced vitality of populations growing on the ash was noticed in planted R. pseudoacacia and spontaneously populated A. fruticosa (P < 0.001) in comparison to T. tentandra and P. alba, due to higher salinity and elevated concentrations of As, Mo, Cu, and Mn in the ash. Thirteen years after planting, as weathering proceeded due to reduced salinity and toxicity, A. fruticosa species showed photosynthesis recovery and had the highest photosynthetic efficiency (P < 0.001), suggesting that it poses adaptive capacity to survive and develop tolerance to stress in such habitats that strongly recommend this species for planting at fly ash lagoons.