Vegetation and Soils in the South Chilean Islands

Abstract

South-western Chile, between 42[degree]S and 56[degree]S is a region of mountainous islands with an oceanic climate and evergreen rain-forest or peat-forming herbaceous vegetation. At Chepu, Chiloe (42[degree]S), the species-rich Valdivian forest grows on ridges with a brown-earth soil, fairly low organic content and a pH around 4.9. The hollows contain Nothofagus - Tepualia woodland with a waterlogged peaty soil of high organic content and pH around 3.9. On the uplands of Chiloe peat formation is also largely confined to hollows: gleys and peaty gleys are widespread and the patches of Nothofagus forest have only thin acid (mor) humus layers. On Chiloe the distribution of Nothofagus forest and mixed (Valdivian) forest is therefore related in part to drainage. On Wellington Island (49[degree]S) blanket peat is present generally below 600 m and differs little in composition or pH from one vegetation type to another. In contrast, the dry northern shores of Navarino Island (55[degree]S) have free-draining shallow brown earth soils and support deciduous forest, and peat formation occurs only in areas of impeded drainage.