Evolutionary Responses to Zinc and Copper Stress in Bladder Campion, Silene Vulgaris (Moench.) Garcke

Terrestrial metal-toxic soils are found all over the world. They originate either from geological anomalies (e.g., ore outcrops, serpentines), or from human activities (e.g., mining, smelting, agricultural use of metal containing fertilizers, pesticides, sludges, etc.). Even extremely metal-toxic soils eventually become vegetated, though often sparsely and without trees. These vegetations are usually poor in species, particularly in parts of the world that have been glaciated during the Pleistocene (Brooks et al., 1985), most probably mainly due to a strong selective effect of metal-toxicity as such (Schat and Verkleij, 1998).