Río Biobío
The natural vegetation of the central section vary from north to south. To a lesser degree vegetation also vary towards the foothills of the Andes and the Chilean Coastal Range. From Santiago to Linares thorny woodlands of "Acacia caven" are dominant. In Ñuble Region two sclerophyll vegetation types cover the territory. These are the associations of "Lithrea caustica"–"Peumus boldus" and "Quillaja saponiana"–"Fabiana imbricata". From Bío Bío River to the south "Nothofagus obliqua" becomes the dominant tree species. Only Llanquihue Lake and the Puerto Montt area are exceptions to this being respectively dominated by "Nothofagus dombeyi"–"Eucryphia cordifolia" and "Nothofagus nitida"–"Podocarpus nubigena".