| dc.description.abstract | Two shrub species, Tamarix tetrandra Pallas (planted) and Amorpha fruticosa L. (naturally colonised), were studied at two fly ash deposit lagoons, weathered 5 and 13 years, in relation to their natural habitat. Both species were assessed in terms of their photosynthetic efficiency (Fv/Fm) of photosystem II, trace elements accumulation (B, As, Mo, Se, Cu, Mn, Zn), and damage symptoms, while the characteristics of the habitat were assessed in terms of trace element content, and the pH and EC of the ash. In both lagoons, B concentrations in ash were within normal range for soils, while As, Mo, Mn and Cu concentrations were higher than the normal range concentrations in soils (P<0.001). The Zn, Mn and Cu concentrations in the tissues of both species from the fly ash lagoons were within the normal range for plants, while the concentrations of B, As and Mo were above the mean values for plants or within the excessive or toxic level. In tissues of A. fruticosa there were higher concentrations of B (levels of above 100 µg/g, P<0.001) and Mo (levels of above 9 µg/g, P<0.001) in relation to T. tetrandra. Excessive accumulation of B and Mo did not cause any visible damage symptoms or the difference in the Fv/Fm (ns) of the A. fruticosa populations at the different-aged ash lagoons and the control habitat. However, differences were found between the populations of T. tetrandra (P<0.001), proved by a discriminant analysis (DA) with a clear distinction between the populations from the natural site (unpolluted), and populations from the ash deposit lagoons (polluted). Also, T. tetrandra displayed damage symptoms, in the form of leaf tip chlorosis and necrosis, and dried brunches - a result of heavy metals accumulation in toxic concentrations. The data suggest that ecophysiological characteristics of naturally colonised species A. fruticosa can be used for modelling future actions of biological restoration of fly ash deposits. | sr |
