Other important biological data bases developed as part of the habitas pianining programs nude known locations of sensitive planes and animais, locations and extent of vernai pool completes, animal micro-tacicas features such as cars. manes, poods, rocky outcrops, elevacion, slope, and the identification of soils which support sensitive plant species. Table 1. Figure 1, and Map 2 all portray information on vegetation for the western repon. Table 1 shows the informa tion contained in the data set, as well as the proportion of the vegetation types within the entire study area and within naturally vegetated areas only Vegetation categones comtained in Figure 1 and Map 2 are aggregations of the detailed vegetation types shown in Table 1. Almost 41 percent of the area within the western region is already devoid of natural habitats. Twenty-eight percent is already developed, ten percent is in agricultural production, and an additional two and one-half percent of the area is so disturbed that the original habitat cannot be identified (primarily due to clearing for development or agricultural use). Fifty-nine percent of the western region remains covered by natural habitats. Of the naturally vegetated areas, 33 percent is covered by chaparral vegetation, 30 percent by coastal sage scrub, 16 percent by grassiands, and 21 percent by all others. Some of the very rare vegetation communities with limited distribution include southern foredunes, southern coastal bluff scrub, maritime succulent scrub, alluvial fan scrub, southern maritime chaparral, southern interior cypress forest, marshes, oak woodlands, and all the riparian habitat types. Figure 1 illustrates the proportion of vegetation types within the natural areas of the western region. Open water, marshes and all riparian vegetation types together comprise only seven percent of the remaining natural areas in the western region. These types of habitats are very productive ecosystems upon which all species are dependent at some time in their lives. recognizable in the samehar mages in the GS af and could be easón trangárias mas de CA Vegetation information for the MHCP came from a number of casting digital sources. These no chudent the Cats of Gerabad HMP the City of Sa Marcas BPMP, the Common of Siam Diego as part of The MHCP and their hatalar conservatam pien song for the unincorporated ares e Comp Penticton Marine Corps Base, Metropolison in ater Drotract as part of their Pape line 6 Cerrader study. In areas where no agoni information for vegetation easted, the photo mater pretation and "beads up” dipotong prionb used in the MSCP were implemented to fill in the Oak woodlands cover roughly five percent of the natural areas. Two percent of the natural area in the western region is water - San Diego and Mission Bays. Although the coniferous forests account for slightly under two percent of the study area, they are abundant in areas outside of the study area. Map 2 depicts the spatial distribution of the vegetation types. The remaining large blocks of habitats occur east of the urbanized area along the eastern fringe of the study area. This is largely dominated by chaparral with some large areas of coastal sage scrub. The northwest corner of the study area also has significant natural areas but these are located on the military lands of the Camp Pendleton Marine Corps Base and the Fallbrook Naval Weapons Annex. In general, the natural areas west of Interstate 5 and Interstate 805 are highly fragmented and are generally of small size. Habitats in the northern portion of the study area also are highly fragmented due to interspersed agricultural activity and low density residential land uses. The larger habitats in the center of the western portion of the study area are surrounded by development and are under intense development pressure. The riparian corridors are highly fragmented and are very narrow. Linkages between large blocks of natural habitats are weak. Figure 1 GENERALIZED VEGETATION * Western San Diego Region (Natural Habitat Areas) Dunes and Beaches Coastal Sage Scrub and Chaparral Mot Coastal Sage Scrub Chaparral Southern Maritime Chaparral Grassland Water and Marshes Oak Woodlands Riparian Scrub Woodland Forest Congerous Forest Eucalyptus Woodlands San Diego and Mission Bay Aggregated from the detailed gain types shown in Table 1 HABITAT EVALUATION MODEL Time and financial resources in the habitat conservation planning programs limited detailed biological surveys and inventories of natural resources. Therefore, predictive habitat evaluation models were used to gauge relative habitat value and evaluate biodiversity within the study areas. A team of local biologists developed a set of criteria on which to model and assess habitat quality. A team of GIS experts developed the Habitat Evaluation Model (HEM) based on the specified biological criteria. The Habitat Evaluation Model was evaluated for its validity and soundness by local biologists, U.S. Fish and Wildlife Service, California Department of Fish and Game, the Scientific Review Panel (representing the State's NCCP), other qualified scientists and the academic community. (See page 27 for a more detailed description of the HEM.) The model is habitat-based. The vegetation layer acts as a predictor or indicator of relative habitat quality and as an indicator of species presence or absence. This data base and the other natural resource data bases are used to rate potential habitat quality and biodiversity of the remaining natural areas in the region. Areas rated with the higher levels of habitat value will be assumed to contain the suite of species which depend upon that habitat for their survival. Figure 2 provides a simple flow chart of the Habitat Evaluation Model, its components, and parameters. |