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small proportion of each site, so we have estimated that the project will eliminate 12 acres of annual grasslands and 1 acre of oak woodland. About half of the irrigated pasture is within the 100-year floodplain; no plans exist to develop the irrigated pastures. The loss of approximately 12 acres of annual grassland (3.7 percent of the project area) is considered a less-than-significant impact because of the small size of the project relative to the substantial areas of these habitats remaining in San Joaquin County. Measures will be adopted to minimize the loss of oaks and other trees on the project site during project design and construction. Oak protection can be ensured by designing the project site plan to protect existing trees wherever possible. If construction is planned immediately adjacent to oaks, an oak protection plan will be submitted by a qualified arborist and submitted to the county and approved before any homesites are constructed. Trees should be carefully protected from construction and landscaping impacts. Tree protection efforts also must be carefully coordinated with fire prevention activities. Oak Revegetation To mitigate for the loss of native oak trees caused by project construction, oak trees will be compensated for at a 5:1 ratio (five oak planting sites for each native oak removed). An average density of three to five rooted acorns per site will be planted in annual grassland or oak woodland in soil similar to that supporting native oaks in the project area. Native oak trees include valley oak, interior live oak, or blue oak with a trunk diameter of 6 inches or greater for a single-trunk tree, or a combined trunk diameter of 8 inches or greater for a multitrunk tree, measured 4'k feet above the ground. This definition is consistent with the natural resources regulations identified in the San Joaquin County General Plan (Sedway Cooke Associates 1990). Acorns will be collected from local trees and planted as rooted acorns during November-January. Rooted acorns will be used because they are less likely than container- grown oaks to be planted with kinked root systems and are therefore better able to rapidly establish deep tap-root systems (Bush and Thompson 1989), which allows them to become self-sustaining more quickly. The planted acorns will be protected with herbivore and weed competition protection kits. All oak planting sites will be augered to a depth of 3 feet, slow-release fertilizer will be added, and the holes will be backfilled and planted. The augering will help promote deep root growth. Weed mats or periodic herbicide treatments will be used to reduce weed competition. The seedlings will also be hand weeded twice a year, once in spring and once in fall; this is essential so that competing vegetation does not compete with the young oaks for moisture and nutrients. Oaks are well adapted to California's Mediterranean climate and need no irrigation if appropriate planting stock and techniques are used (Bush and Thompson 1989). However, to enhance oak survival and growth, the oaks will be watered approximately every 25