A community of lichens surrounds the branches of this Garry oak and catches the late afternoon side-light of mid-November in Ruckle Provincial Park (Saltspring Island, British Columbia). A survey of this epiphytic life on twenty years old Quercus garryana branches in the Willamette Valley of Oregon revealed over thirty-five species of macrolichens, mosses and liverworts can be found on the branches of Garry oak trees in a single grove of the plants. This suggests some dynamic forces are occurring, and indeed, the growth of a new branch opens up an uncolonized area that is subject to ecological succession processes. Some of the epiphytic species initially colonize and jostle for light, water and nutrients, but these are later subjected to a slowly changing environment as branches expand, new branches are grown, and other epiphytes become established. Over time, the composition of the community of epiphytes on older branches changes; see: Stone, D. 1989. Epiphyte Succession on Quercus garryana Branches in the Willamette Valley of Western Oregon. The Bryologist. 92(1): 81-94. doi:10.2307/3244020.

Please note that a second common name for this species is Oregon white oak; for a discussion of the common name, see this previous BPotD entry on Quercus garryana.