Effects of a copper smelter on a grassland community in the Puchuncavi Valley, Chile

A grassland formation has been subjected to pollution generated by the Vent anas copper smelter since 1964 (Puchuncavi Valley, central zone of Chile) w ith extensive damage to local vegetation and important changes in soil char acteristics. The aims of the study were (1) to detect soil parameters that best explain changes observed in plant species richness and abundance and ( 2) to determine if pollution-derived stresses have also affected regenerati on capabilities of plant communities from the soil seed bank. The grassland was quantitatively analysed in terms of physicochemical soil characteristi cs, plant species diversity and abundance, and soil seed bank species compo sition and abundance. Results showed that a decrease in total soil nitrogen explained 13% of the changes detected in plant abundance while soil pH and 0.05 M EDTA extractable copper explained 10% and 7%, respectively, of the vegetation change. It was also found that the pollution has already affecte d plant species regeneration capabilities from the soil seed bank and the m icrosite distribution of the seeds in soils. (C) 2000 Elsevier Science Ltd. All rights reserved.