Structure and composition of foothill woodland

Structure and species composition were sampled in 49 stands of foothill woodland in the vicinity of Hastings Reservation. Most of the stands were nearly pure blue oak (Quercus Douglasii). There was an average of 207 trees per acre, but an average of only 75 saplings per acre. The majority of saplings were blue oaks so that blue oak is not being replaced by other species. Fire and livestock grazing have probably not limited blue oak reproduction recently, but deer browsing limits the growth of many oak seedlings. Annual right counts on stumps showed that the majority of blue oak trees originated over a relatively short period from approximately 1870 to 1890, a dynamic period of land use in the study area, but the factor or factors that accounted for this flush of oak reproduction cannot be determined. Amounts of Stipa were not significantly different. An ordination of all 17 stands using species frequency in quadrates showed a pattern consistently related to percentage slope.