Rogue-Umpqua Forest-Shrub Zone Complex
Occupying valleys in the rainshadow of the Siskiyou Mountains is a vegetation mosaic exhibiting many xeric characteristics. Woodlands are dominated by Oregon white oak (Quercus garryana), with California black oak (Q. kelloggii) on mesic sites. Pacific madrone, ponderosa pine, sugar pine (Pinus lambertiana), and incense cedar distinguish this zone from Willamette Valley forest. On shallow soils, south slopes' and recently burned areas, sclerophyllous shrub communities are found with narrow-leaved buckbrush (Ceanothus cuneatus) and white-leaved manzanita (Arctostaphylos viscida).