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Seasonal Wetlands Seven vernal pool sites held water throughout the late winter and the early 1992 spring period(Figures 4.7-1 and 4.7-8). Vernal pools are small, seasonal wetlands that form in a shallow depression in relatively level terrain due to the lack of rainfall percolation through an impervious soil layer. As the winter rains subside and temperatures increase throughout spring,the pool water continuously evaporates, leaving a zone of moist ground immediately surrounding the remaining water. This creates an ever- changing set of miniature habitats for highly specialized plant and animal species that thrive during this brief spring period and then die, leaving behind drought resistant seeds and eggs which will renew the cycle in the following year. Many of these species are found only in such vernal pool habitats, and since the majority of these habitats in California have been destroyed by agriculture and grazing,a number of such species are now classified as threatened or endangered. The dominant vernal pool plant species on the project site is Eryngium vaseyi. Also present is Plagiobothrys stipitatus and Limnanthes douglasii. None of these species have common names. As the pools dried, hydrophilic species present in other wet areas on the project site appeared within the pool margins. These included a small sedge species (Carex sp.) and curly dock (Rumex crispus). None of the species identified in the vernal pool basins are listed under any protective categories by either the California Native Plant Society or the California Department of Fish and Game. Plant Communities Foothill Woodland A foothill woodland community dominates the project site and exists in three different forms. The most extensive of these is an oak savanna association composed primarily of interior live oak (Quercus wislizenii) and valley oak (Quercus lobata)with smaller numbers of coast live oak (Quercus agrifolia) and blue oak (Quercus douglasii)scattered throughout(Figure 4.7-1). This savanna association is also somewhat unusual in that it contains relatively large numbers of California buckeye(Aesculus californica) which occur both singly and in small clusters. Tree density in the savanna association is quite variable, ranging from only a few trees per acre up to as many as 20 or more mature specimens per acre plot (Figures 4.7-9). The most spectacular segment of the foothill woodland community occurs in the form of a closed canopy forest known locally as Brovelli Woods. This excellent example of a foothill/riparian woodland stand remained essentially untouched until 1989 when approximately 12 per cent of the total 90 acre stand was cleared in the initial preparation of the proposed golf course. Figure 4.7-10 shows the inroads into the forest stand that the clearing project produced. Twenty to 30 years previously, approximately 10 acres of the forest had been cleared for farming purposes (Brovelli, 1989). This previously cleared area is currently being restored by the applicant. Interior live oak numbers exceed those of valley oak in approximately a 4:1 ratio, with occasional specimens of box elder(Acer negwndo),Oregon ash(Fraxinus oregona),and California buckeye scattered throughout. The forest contains trees in many age categories, with some of the older specimens averaging well above 100 years. The later estimates were obtained from annular ring counts from stumps that have been pulled out and deposited in piles near the forest edge. This large range of tree age along with a good crop of oak seedlings indicates that this forest has been functioning in a normally ecological 7