V. RARE AND ENDANGERED SPECIES

Ever since scientists and explorers began to document plants and animals systematically, they have also begun to note changes in the geographic distribution of the species. Changes in the number of species occur naturally over time. However, the accelerated endangerment and extinction occurring now is being attributed to urbanization, agriculture, logging, mining, pollution, and domestication by the nursery and pet industries.

Although there are certain characteristics of the natural history of California's rare fauna and flora that have been studied in depth and carefully recorded, many aspects of their ecology remain unknown. Three areas of study which have received attention in relation to rarity and endangeredness are the longevity of plants, habitat preference, and chemical and physical properties of substrates. The first area explored shows a trend among extinct, rare, and endangered plants to be annuals rather than perennials. Another trend is that they tend to inhabit lowland areas, particularly chaparral, coastal scrub, grassland, and wetland habitats. The third area studied, substrate preferences, reveals patterns of endemism related to serpentinite, carbonates (limestone and dolomite), and a negative correlation between rare endemics and gabbro and gypsum. Sandy and rocky substrates appear to support many more rare endemics than others. Similar ecological studies relating to rare and endangered species in Poly Canyon could well contribute to the understanding of California's sensitive species. A few ideas for future studies are given in the section "Ideas for future research."

Plants presumed to be extinct are those which have been actively sought in likely areas, but not found for a number of years or those whose habitat is known to have been destroyed or significantly modified. Rare species are those which occur in limited numbers in the wild and/or have a limited range of distribution. The distribution is considered limited when the habitat in which the species are found is relatively rare. Rare species can become threatened or endangered through habitat destruction. Endangered species are rare, and their wild populations are threatened with extinction either because too few individuals survive with which the species can reproduce or because those individuals are threatened.

According to these descriptions, the California Native Plant Society (CNPS) places sensitive plants in one of five categories: 1A, presumed extinct in California; 1B, rare, threatened, or endangered in California and elsewhere; 2, rare, threatened, or endangered in California, but more common elsewhere; 3, more information needed; and 4, plants of limited distribution - a watch list (see Table 5). Based on a total of 6,300 species, 1,742 species or nearly 28% of California's plants are considered extinct, rare and endangered, or threatened by their limited distribution. Of these, in Poly Canyon, there are five plants which are considered rare/endangered in California and elsewhere (list 1B): San Luis mariposa lily (Calochortus obispoensis), San Luis Obispo County morning-glory (Calystegia subacaulis ssp. episcopalis), San Luis sedge (Carex obispoensis), Brewer's spineflower (Chorizanthe breweri), and Jones' Layia (Layia jonesii).

TABLE 5
CALIFORNIA NATIVE PLANT SOCIETY CLASSES OF RARE AND ENDANGERED SPECIES

One plant is considered rare/endangered in California, but more common elsewhere (list 2): groundsel (Senecio aphanactis). Seven plants (four species, two subspecies, and one variety) have a limited distribution (list 4): Bishop manzanita (Arctostaphylos obispoensis), Club-haired mariposa lily (Calochortus clavatus ssp. clavatus), San Luis Obispo Dudleya (Dudleya abramsii ssp. murina), Southern California black walnut (Juglans californica var. californica), small-leaved lomatium (Lomatium parvifolium), Pringle's yampah (Perideridia pringlei), and Hoffmann's sanicle (Sanicula hoffmannii). See Table 6.

Through its "R-E-D Code," the California Native Plant Society further describes the vulnerability of sensitive plant species, elaborating on their Rarity, Endangerment, and Distribution. Rarity "addresses the extent of the plant, both in terms of numbers of individuals and the nature and extent of distribution." Endangerment "embodies the perception of the plant's vulnerability to extinction for any reason." Distribution "focuses on the overall range of the plant." Each of these three categories has three subcategories which represent degrees of concern, subcategory 1 representing the least concern, subcategory 3 the most (see Table 7).

Under California state law, the official status of plants is described by one of four categories: CE (listed as endangered), CT (listed as threatened), CR (listed as rare), or CC (candidate for listing). Under federal law, there are ten categories: FE (listed as endangered), FT (listed as threatened), PE (proposed as endangered), PT (proposed as threatened), C1 (enough data are on file to support federal listing), C2 (data are insufficient to support federal listing), C2* (data are insufficient to support federal listing, but the plant is presumed extinct), C3a (extinct), C3b (taxonomically invalid), or C3c (too widespread and/or not threatened).

Table 6.
RARE AND ENDANGERED PLANT SPECIES OF POLY CANYON

Table 7.
CALIFORNIA NATIVE PLANT SOCIETY R-E-D CO

DE

In Poly Canyon, two plant species are included on list C2: San Luis Obispo County morning glory (Calystegia subacaulis ssp. episcopalis) and Jones' Layia (Layia jonesii). Category C3c includes six plant species in Poly Canyon: San Luis Obispo mariposa lily (Calochortus obispoensis), San Luis sedge (Carex obispoensis), Brewer's spineflower (Chorizanthe breweri), San Luis Obispo or Mouse-leafed Dudleya (Dudleya abramsii ssp. murina), Pringle's or adobe yampah (Perideridia pringlei), and Hoffmann's sanicle (Sanicula hoffmannii). Refer back to Table 6.

The California Native Plant Society further categorizes the status of plant species that have no current state or federal standing as either "CEQA" or "CEQA?" The CEQA (California Environmental Quality Act) listing indicates "that CEQA consideration is mandatory (Lists 1 and 2)." The CEQA? listing indicates that CNPS has "recommended evaluation for CEQA consideration (Lists 3 and 4)." One plant from Poly Canyon is in the CEQA category: Groundsel (Senecio aphanactis). Four plants from Poly Canyon are in the CEQA? category: Bishop manzanita (Arctostaphylos obispoensis), Club-haired mariposa lily (Calochortus clavatus ssp. clavatus), Southern California black walnut (Juglans californica var. californica), and small-leafed lomatium (Lomatium parvifolium). Refer back to Table 6.

As for animal species, rare and endangered listing is governed by the California Fish and Game Commission (state list) and the U. S. Secretary of the Interior or the U. S. Secretary of Commerce (federal list). The California Department of Fish and Game, defines "Special Animals" as "all the vertebrate and invertebrate taxa of concern to the Natural Diversity Data Base (NDDB), regardless of their legal or protection status." Special Animals include taxa which are "biologically rare, very restricted in distribution, declining throughout their range, or at a critical stage in their life cycle when residing in California." They may belong to "populations in California that may be peripheral to the major portion of the taxon's range, but which are threatened with extirpation within California." They are often "taxa closely associated with a habitat that is declining in California (e.g., wetlands, riparian, old growth forest)." Coded taxa "fall into one or more of the following categories: officially listed or proposed for listing under the State and/or Federal Endangered Species Acts, State or Federal candidate species for possible listing, California Department of Fish and Game 'Species of Special Concern,' or designated as 'sensitive' by Federal land managers" such as the Bureau of Land Management (BLM) or U.S. Forest Service (USFS). See Table 8.

The NDDB categorizes sensitive animal species according to the global or overall condition of the species throughout its range (G), the overall condition of the subspecies throughout its range (T), and the overall condition of the species throughout its range in California (S). The NDDB ranks each taxon in each of these categories from 1 to 5 according to the number of individuals or acres of habitat estimated to remain: 1 is the least (less than 1,000 individuals or 2,000 acres remain), 5 the most (the population is demonstrably secure due to being commonly found throughout the world). Within the G category, other subcategories include: H (sites which are historical, where the species has not been seen in 20 years, but habitat still exists); X (extinct throughout its range); and XC (extinct in the wild, but still existing in cultivation or in zoos). The numerical classifications of category S are further subdivided into .1 ( very threatened), .2 (threatened), or .3 (no current threats known).

Table 8.
CALIFORNIA DEPARTMENT OF FISH AND GAME - NATURAL DIVERSITY DATA BASE
SPECIAL ANIMALS CODE

Other subcategories of the state ranking S include: H (all California sites are considered historical, and no habitat is known to remain) and X (all California populations are presumed to be extinct). For all categories (G, T, and S), ? means that threats to the species have not been sufficiently documented. Refer back to Table 8.

In Poly Canyon, a few special animals have been reported or are expected to occur. These include the Coast Range newt (Taricha torosa torosa), California red-legged frog (Rana aurora draytonii), Foothill yellow-legged frog (Rana boylii), Southwestern pond turtle (Clemmys marmorata pallida), California horned lark (Eremophila alpestris actia), Loggerhead shrike (Lanius ludovicianus), Least Bell's vireo (Vireo bellii pusillus), pallid bat (Antrozous pallidus), and American badger (Taxidea taxus). See Table 9. Invertebrate species of concern have not been addressed in this report.

Table 9.
RARE AND ENDANGERED ANIMALS OF POLY CANYON