Contribution of downed woody material by blue, valley, and coast live oaks in central California

Information on downed woody material (DWM) is necessary to produce guidelines to manage and maintain faunal diversity in California oak (Quercus spp.) woodlands. Mie sampled DWM within circular plots, one each centered on 122 blue (Quercus douglasii), 112 coast live (Q. agrifolia), and 74 valley (Q, lobata) oak trees in central California. Most DWM pieces that occurred within plots were small. Of large (greater than or equal to 25 cm diameter) pieces, 83 percent occurred under coast live (40 percent) and valley (43 percent) oaks. Mean diameter, length, number, and volume of pieces of DWM tinder blue, coast live, and valley oaks were Mot statistically different across the three tree species (all P >0.10). However,for each variable, mean values of pieces were lower under blue oaks versus under coast live and valley oaks. Approximately 50 percent of the pieces under each species were moderately decayed, compared to approximately 25 percent either sound or soft. Management practices in oak woodland may alter the abundance and distribution of DWM. Therefore, emphasis should be given to maintenance of DWM for vertebrate and invertebrate wildlife.