 oak woodlands and forests provide favorable habitat for wildlife (6) and also produce substantial amounts of forage for sheep and cattle (33). Infrequently, cattle are poisoned by foraging on oak; one instance involving Oregon white oak has been documented (37).
Oak-dominated forests in the western part of the Willamette Valley in Oregon have a higher diversity of birds in all seasons than adjacent conifer forests (3). Oregon white oak and ponderosa pine-Oregon white oak associations are preferred brood habitats for Merriam's wild turkey in south-central Washington (39).
Greenhouse experiments have shown that Oregon white oak is a good host for the gourmet truffle, Tuber melanosporum (43). The feasibility of managing Oregon white oak stands for truffle production, as many oak stands are managed in Europe, is being investigated.
Though Oregon white oak populations in Washington are disjunct and scattered, the chemical and morphological characteristics of their foliage are similar (71). Genetic differences appear so minor that seed distribution from a common source by Indians has been postulated. Ecotypic variation was observed in top and root growth of young seedlings from seed collections made from Corvallis, OR, southward (43). First-year seedlings from northern sources were taller and heavier.
Quercus garryana hybridizes naturally with four other oaks. Quercus x subconvexa Tucker (Q. durata x garryana), a small tree found in Santa Clara and Marin Counties, CA, is noteworthy because of its morphologically dissimilar parents-Q. garryana is a deciduous tree, Q. durata an evergreen shrub, and the hybrid is tardily deciduous (74). Quercus x howellii Tucker (Q. dumosa x garryana) is also a small tree found in Marin County and a hybrid between a deciduous tree and an evergreen or tardily deciduous shrub or tree. Quercus x eplingii C. H. Muller (Q. douglasii x garryana), a tree with deciduous leaves, is found in Lake and Sonoma Counties, CA (75). Hybrids between Q. garryana and Q. lobata are also found in Sonoma County (4).