1. Natural Land:

Natural land is land with a significant cover of natural vegetation. Natural vegetation in this context includes all native California natural communities and includes forestlands, shrublands, native and non-native grasslands, non-irrigated land, grazed land, and vacant or disturbed natural land. Natural land excludes lands subject to intensive agriculture and urban uses. Disturbed land or land recently cleared may still be restorable and should be included in the evaluation. The California Department of Conservation Farmlands Mapping and Monitoring Program is one way to identify natural lands: natural lands are areas classified as "grazing" or "other." Generally, land not mapped by the Department of Conservation can be assumed to be natural in eastern portions of the study area and urban in western portions.

CSS includes landscape areas supporting primary or secondary cover of characteristic CSS plant species dominants as defined by the SRP, Special Report No. 2, March 1992. A generalized map of CSS and a summary description is attached as Attachment A.

The largest CSS patches in the subregion should be considered as possible core areas for future reserves. Because CSS distribution is naturally patchy, patch size needs to represent presence of CSS habitat at an intermediate spatial scale and needs to integrate over minor fragmentation and differences in vegetation mapping methodologies. Habitat patches should not be discounted as "too small" merely because they are mixed with other natural vegetation types. It is, however, appropriate to exclude landscape areas that are highly urbanized.

The objective of the evaluation process is to identify larger patches of CSS in the subregion. These are the Higher Value Districts. The method of finding the larger patches can be adjusted to conditions present in each subregion. The SRP recommends determining the percent of CSS cover in a neighborhood around individual CSS patches. When the entire subregion is evaluated, those patches of CSS habitat with the highest percent CSS cover in the neighborhood, cumulatively representing 50% or more of all CSS cover within a subregion can be identified. Neighborhoods should have a radius of 1/2 to 1 mile. This spatial scale for planning reflects biological characteristics of CSS species and the need for agglomerations of CSS on a scale potentially suitable for incorporation into a reserve networks. The determination of the "core 50%" also takes into account the presence of urban and non-CSS natural land.

CSS patches close to a core can be identified by measuring direct, straight-line distances. Appropriate spatial scale must be determined for each subregion and should be on the order of one-quarter to one-half mile.

Natural lands, and even lands in intensive agriculture, may contribute to reserve network connectivity. Corridors must be drawn such that each Higher Value District is connected to the closest adjacent districts. A geometric corridor between Higher Value Districts is defined by drawing two straight lines tangent to each district. Boundaries can be adjusted as necessary to reflect natural features such as riparian areas that may curve outside of a defined geometric corridor.

A test must identify areas 1) that need special protection in the interim to reduce the likelihood of take of species and 2) that may have long-term value due to special conditions that support significant populations of highly endemic species, rare sub-habitat types, or vegetation subcommunities.

What constitutes significant populations must be determined for each subregion. For target species, the SRP considers habitat that supports a portion of a local population with five or more pairs of gnatcatcher or cactus wrens to be significant. For other species of plants or animals (including those species listed or candidates for listing), the SRP considers habitat that supports a portion of a local population representing more than 20% of the known population of the subregion to be significant.

The species presence test specifically means that each parcel under consideration for development will be subject to a species clearance: a survey for target species and other rare plants and animals. The survey should use techniques specified by the SRP or equivalent methods. (See SRP Survey Guidelines.)

Species presence during a one-time survey is not a reliable measure of habitat value. Moreover, species survey work is also expensive and time consuming. For this reason, the basic methodology to identify potential reserves relies most heavily on less variant aspects of the landscape.

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