White poplar (Populus alba) as a biomonitor of trace elements in contaminated riparian forests

11 pages, 3 figures, 5 tables, 58 references. We thank Francisco Cabrera, Rafael López and José María Alegre for their help in different stages of the study, and to Luis V. García for his comments on the manuscript. Trace element concentrations in plants were determined by Olga Cazalla in the Centre for Scientific Instrumentation, University of Granada.

Trees can be used to monitor the level of pollution of trace elements in the soil and atmosphere. In this paper, we surveyed the content of eight trace elements (As, Cd, Cu, Fe, Mn, Ni, Pb and Zn) in leaves and stems of white poplar (Populus alba) trees. We selected 25 trees in the riparian forest of the Guadiamar River (S. Spain), one year after this area was contaminated by a mine spill, and 10 trees in non-affected sites. The spill-affected soils had significantly higher levels of available cadmium (mean of 1.25 mg kg 1), zinc (117 mg kg 1), lead (63.3 mg kg 1), copper (58.0 mg kg 1) and arsenic (1.70 mg kg 1), than non-affected sites. The concentration of trace element in poplar leaves was positively and significantly correlated with the soil availability for cadmium and zinc, and to a lesser extent for arsenic (logelog relationship). Thus, poplar leaves could be used as biomonitors for soil pollution of Cd and Zn, and moderately for As.

The PICOVER program from the Regional Ministry of Environment, Sevilla, Spain, supported this study.

Peer reviewed