Phytophthora cinnamomi and oak decline in southern Europe. Environmental constraints including climate change

Abstract

One of the most destructive of all tree root pathogens, the oomycete fungus P. cinnamomi, is associated with mortality and decline of Quercus suber and Q. ilex in the Mediterranean region. The symptoms and distribution of this decline are described. It is soil borne and requires warm, wet soils to infect roots. Together with drought, it may be a major predisposing factor in the Iberian oak decline. Its possible role in this decline including its interaction with drought is discussed, and a generalised working hypothesis of decline is presented. The potential influence of climate warming on the activity of P. cinnamomi is also considered.