Authors measured the removal of acorns and seedling recruitment from surface-sown and buried acorns for two years, at two sites in California, a north-slope forest and a ridgetop savanna. Throughout the experiment, year, planting position (surface or buried), and rodent herbivory influenced blue oak (Quercus douglasii) seedling recruitment the most. Pocket gophers (Thomomys bottae) were the major predator of buried acorns. Cattle were also considered a major predator in one year of the study, as they crushed and consumed many acorns, compacted the soil and reduced above-ground vegetation, thus making surface acorns more visible to other predators and microsites less suitable for blue oak germination and establishment. The results of this study indicate that several factors are interacting to limit the recruitment of blue oak in California and that increasing blue oak will require rigorous, adaptive management practices and further investigation of factors affecting seedling recruitment and survival.
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