This section describes the biological setting in which the goal of assembling a 500,000 acre Conservation Area for conservation of up to 146 plant and wildlife species would be achieved.

3.1.1 Data Sources and Limitations

A comprehensive biological and physical database that includes information on vegetation, species occurrences, wetlands, topography, soils, and aerial photography is available for the proposed MSHCP Plan Area and was used in the development of the Plan. This section describes the various data layers used to develop the proposed MSHCP.

MSHCP Vegetation

The proposed MSHCP vegetation map is depicted in Figure 2.5 (in Section 2.0). This map was prepared by Pacific Southwest Biological Services (PSBS) and KTU+A in 1995. The methodology used to assemble the map is described in detail in the Western Riverside County Multi-Species Habitat Conservation Plan Phase I Information Collection and Evaluation Report (PSBS and KTU+A, February 1995). Data sources include aerial photography (1 inch = 2,000 feet, 1992-1993), existing generalized vegetation maps (CNDDB, Weislander Statewide Vegetation Survey, U.C. Santa Barbara Southern California Ecoregion "GAP" Analysis, 1991 Dangermond/RECON MSHCP Strategy Report). Methods used to create and interpret vegetation data include aerial photographs, edge matching, digitizing, and geographically registering the data. Areas of concern were ground-truthed. Vegetation types were classified according to Holland (1986).

The proposed MSHCP vegetation map represents conditions at the time the data were assembled, in this case 1991-1995; the current extent and character of vegetation communities may differ from that depicted on the proposed MSHCP vegetation map. Published and anecdotal data suggest that ecosystem state transition is occurring within some portions of the proposed Plan Area ­ in particular, fire suppression has resulted in the conversion of frequently burned chaparral and coastal sage scrub to grassland, and also in shifts from Ponderosa pine and Jeffrey pine to incense cedar and white fir (Minnich, et al., 1995; Keeley, 1990; Zedler, et al., 1983). The proposed MSHCP incorporates features to update the vegetation map as new information is obtained, such as the development of a new vegetation map as part of the proposed MSHCP Monitoring Program. The timing and methodology for developing this map are described in Section 5.3 of Volume 1 of the proposed MSHCP.

This approach is compatible with the criteria-based format of the proposed MSHCP, which calls for assembly of 153,000 acres of additional reserve lands from within an approximately 300,000-acre Criteria Area. Reserve assembly will involve review of a variety of project-specific vegetation data to refine and guide the reserve assembly process. This criteria-based format differs somewhat from the large-scale NCCPs/HCPs for which a specific reserve boundary is delineated on a map at the time of permit issuance. With that type of approach, validation of the vegetation map at the landscape level may be more important than under the criteria-based approach selected for the proposed MSHCP.

The organizational structure established for the proposed MSHCP, as described in Section 6.6 of the proposed MSHCP, also provides opportunities to incorporate new information during the term of the proposed MSHCP permit.

Coastal Sage Scrub Habitat Quality Model

As part of the 1995 PSBS/KTU+A work referred to previously in the discussion of proposed MSHCP vegetation, PSBS and KTU+A modeled and evaluated variables potentially relevant to the suitability of coastal sage scrub habitat within the proposed Plan Area for the coastal California gnatcatcher. A detailed description of the methodology used to develop the model is presented in their report (PSBS and KTU+A, 1995). Variables used in the model include elevation, degree of slope, patch size, patch shape, proximity to other coastal sage scrub patches, and adjacent land use. The modeling designated the quality of coastal sage scrub in the proposed Plan Area and suitability for the gnatcatcher as very high, high, moderate, low, or very low. The primary limitations of the model with respect to proposed MSHCP planning are the age and quality of the database used to develop the model. In this regard, the model has the same limitations as the proposed MSHCP vegetation map.

MSHCP Species Occurrence Database

The University of California, Riverside (UCR) assembled a species occurrence database for use during the proposed MSHCP planning process. This database is accessible at http://ecoregion.ucr.edu/. The web site is a clearinghouse for biological information for the proposed MSHCP. Occurrence data were compiled from museum records, USFWS data, published and unpublished accounts, environmental impact reports, and field notes of local naturalists. As of August 2001, this database contained over 12,800 records.

The UCR species occurrence database incorporates accuracy and precision codes. For the proposed MSHCP species accounts included in Section B of the MSHCP Reference Document ­ Volume II of the proposed MSHCP, validity of the various occurrence data is cited; less valid data are not used to draw conclusions regarding species conservation. For example, species locations that have low precision are not valid for defining conservation areas.

Herbarium Data Sources and Limitations

Additional occurrence/distribution data were gathered for particular plant species within the proposed MSHCP Plan Area from herbarium specimens at the San Diego Natural History Museum (SDNHM), Rancho Santa Ana Botanical Gardens (RSA) herbarium, and the UCR herbarium. Most of the occurrence and distribution data were downloaded from databases at SDNHM, RSA, and UCR. Additional data were hand-copied from herbarium specimens that had not been previously databased (e.g., the synoptic collection at RSA). The location data from each specimen were either copied or translated into one coordinate system to generate a point coverage depicting the spatial distribution of the sensitive plant species within the Plan Area. Approximately 800 data points were assembled with dates ranging from 1880 to 2001.

Precision codes were applied to individual occurrence records based on the quality and extent of both quantitative and qualitative geographic data using the precision code guide developed for the UCR species occurrence data.

Quantitative geographic data included species occurrences whose locations were reported as latitude and longitude in degrees, minutes, and seconds; as UTM coordinates in meters; or as locations described using township, range, and section designations. Species occurrences containing quantitative geographic data are considered to be the most valid.

Qualitative geographic data include species occurrences whose locations were reported as written descriptions. Species occurrences with only qualitative geographic data were generally given a lower precision rating, depending upon the quality of the specific information provided.

It is recognized that new data regarding species occurrences will become available during the proposed MSHCP implementation process including data assembled as part of the proposed MSHCP Monitoring Program described in Section 5.3 of the proposed MSHCP. The species-specific conservation objectives and the proposed MSHCP Management Plan contain measures to incorporate new occurrence data as they become available.

Wetlands

Wetlands information for the proposed Plan Area primarily is derived from the proposed MSHCP vegetation map. Other potential wetland areas, including streams, rivers, canals or ditches, ponds, and lakes, were mapped by Earth Consultants International (ECI) as part of the geologic hazards mapping assembled for the RCIP General Plan Update. A separate riparian GIS coverage was created by UCR research assistants in 2000 through aerial photo interpretation of 1996 digital orthophoto quarter quadrangles (DOQQs) of the Plan Area. Riparian areas were "heads up" digitized and categorized into four wetland habitat types based on dominant vegetation cover. All of these data were combined to create an exhibit depicting mapped wetland resources in the proposed Plan Area (Figure 3.1.1).

The wetlands map has the same limitations as the proposed MSHCP vegetation map, and those limitations are addressed in the proposed MSHCP in the same manner as those for the vegetation map. With respect to wetlands mapping, the U.S. Army Corps of Engineers (U.S. ACOE) is currently developing a functional assessment and programmatic wetlands delineation for the San Jacinto River and Upper Santa Margarita River Watersheds within the Plan Area as part of the U.S. ACOE Special Area Management Plan (SAMP) process currently underway for those watersheds.

A planning-level wetland delineation for the San Jacinto and Santa Margarita watersheds was recently completed, which was based on a modification of the standard delineation sampling protocols outlined in the U.S. ACOE Wetland Delineation Manual, color infrared image interpretation, and field verification visits. The delineation resulted in identification of 201 vegetation community types and development of a wetlands ratings system. Although this delineation produced a finer level of aquatic resource mapping, the U.S. ACOE wetlands map is limited in that it does not cover the entire MSHCP Plan Area.

Soils

The U.S. Department of Agriculture (USDA), Soil Conservation Service (SCS) (Knecht, 1971), and State Soil Geographic (STATSGO) database for California provided the generalized soils map that depicts 25 general soils types for the proposed Plan Area. In addition, the following soil types were digitized from 1973 SCS maps (at a scale of 1:15, 840 or 1 inch = 1,320 feet) and registered with digital Eagle Aerial images onscreen:

• Altamont clay (AaD, AaE2, AaF, Abf)
• Auld clay (AuC, AuD, AyF)
• Bosanko clay (BfC, BfD)
• Claypit
• Domino clay (Dt, Du, Dv, Dw)
• Porterville cobbly clay (PoC, PrD, PsC, PtB, PvD2)
• Traver (Tr2, Ts, Tp2, Tt2)
• Willows (Wg, Wh, Wm, Wn)

Soils were digitized in areas identified by DUDEK biologists to enable quantitative analysis of soils considered important for the conservation of certain plant species. Soils listed above were digitized for the following USGS quadrangles: Alberhill, Bachelor, El Casco, Elsinore, Hemet, Lake Mathews, Lakeview, Murrieta, Perris, Romoland, San Jacinto, Steele Peak, Sunnymead, Temecula, Wildomar, and Winchester.

A digital coverage for Delhi soils was also obtained from USFWS and used in the species analysis for the Delhi Sands flower-loving fly. The area currently identified as Delhi soils within the Plan Area may be updated based on site-specific mapping of Delhi soils by a qualified soil scientist within 3 years after a permit issuance.

 

 

Topography

 

 

USGS topography was used for proposed MSHCP planning process. In addition, specific elevation analyses were developed using a 500-meter interval coverage developed from a USGS 30-meter digital elevation model (DEM). A vegetation map with hill-shaded relief was also used.

The topographic database is not considered to be limited for purposes of landscape-level MSHCP planning. It is anticipated that newly flown, more accurate topography will be available for certain areas for evaluation of specific Covered Activities and other proposed MSHCP reserve assembly, management, and monitoring issues during the proposed MSHCP implementation process.

Aerial Photography

Aerial photographs were obtained from Eagle Aerial and include digital aerial images flown in fall 1999 for western Riverside County and flown on May 4, 2001, for the Temecula Valley (pixel size: 1 meter).

USGS DOQQs were obtained from USFWS and cover the majority of the proposed MSHCP Plan Area, with the exception of U.S. Forest Service (USFS) lands. The DOQQs were flown on September 30, 1996, false color infrared, 1-meter resolution.

The aerial photography database is not considered to be limited for purposes of landscape-level proposed MSHCP planning. It is anticipated that current aerial photography will be available throughout the long-term proposed MSHCP implementation process to permit evaluation of specific Covered Activities and other proposed MSHCP reserve assembly, management and monitoring issues as they arise.

Literature

A wide variety of literature was reviewed and used for the proposed MSHCP planning process. Literature citations for the species accounts are provided for each proposed MSHCP species in Section B of the MSHCP Reference Document, Volume II of the MSHCP. Other literature references are listed in Section D of the proposed MSHCP Reference Document, Volume II of the proposed MSHCP. It should be noted that a large body of scientific literature was made available by UCR. This literature was thoroughly reviewed but only specifically relevant literature was cited as appropriate. For example, many of the species references contained little or no relevant information for conservation planning in the proposed Plan Area.

3.1.2 Bioregions

The review of databases and literature shows that the exiting vegetation database for the Plan Area does not adequately reflect the considerable variety of plant and animal species in western Riverside County. Grinnell (1933) described biotic or "life" zones for Southern California, but the scale of these life zones is generally too coarse to be useful for analyzing potential biotic variation within the proposed Plan Area. To address this limitation and better depict potential variation within and among species, a biogeographical map (referred to here simply as bioregions) was created to help describe diversity of habitats on a regional scale within the proposed Plan Area. This was done under the assumption that regional diversity in conserved areas translates directly into biological and genetic diversity. By ensuring regional representation of species and redundancy of resources, there is some buffer against the effects of natural and anthropogenic catastrophic events, such as wildfires, floods, and disease, on conserved areas.

Using existing information on soils (SCS), elevation (30-meter DEM data), topography (hill-shaded DEM mapping), and local expertise, a draft map that roughly demarcates the general bioregions within the proposed MSHCP Plan Area was drawn. Existing levels of human disturbance (urbanization, intensive agriculture, grazing, etc.) were considered because they have had a substantial effect on the current biota of the proposed Plan Area. While discrete bioregion boundaries cannot capture the natural continuum or gradient of environmental changes and transitions within the proposed Plan Area, these boundaries roughly represent areas where species turnover and habitat zone transitions are pronounced in relation to changes in landform and other environmental features. Because continuous climatic maps showing precipitation and air temperature (maxima, minimi, means) were not available, landform and elevation were used as surrogates for these variables to draw the initial map. DUDEK staff and subconsultants knowledgeable about the distribution of plant and animal species in western Riverside County then fine-tuned the boundaries where elevation and landforms did not accurately reflect changes in species and habitat distributions. This methodology is similar to the approach used to develop bioregions for San Diego County (T. Oberbauer, personal communication, 2000). The validity of these bioregions was initially tested by examining the distribution of vegetation types and sensitive species that fall within them. On the basis of existing data, it was determined that the bioregions appear to reflect the different suites of species and vegetation communities in the proposed Plan Area. As a work in progress, these boundaries are subject to change based on further analyses, scientific study, and input from experts familiar with western Riverside County.

Seven distinct bioregions were identified: Santa Ana Mountains, Riverside Lowlands, San Jacinto Foothills, Agua Tibia Mountains, Desert Transition, San Bernardino Mountains, and San Jacinto Mountains (Figure 2.4). The characteristic features of each bioregion are described below.

Santa Ana Mountains Bioregion

The Santa Ana Mountains Bioregion extends south of State Route 91 (SR-91) to the Riverside/San Diego County line and occurs west of Interstate 15 (I-15). It encompasses the Cleveland National Forest and areas north of the Santa Margarita River. This bioregion generally occurs at elevations above 2,000 feet and supports Diegan coastal sage scrub, mesic chaparral, and sparse coniferous vegetation. The Santa Ana Mountains Bioregion is heavily influenced by coastal climate factors such as fog, rainfall, and wind. This bioregion is relatively undisturbed and not urbanized.

Riverside Lowlands Bioregion

The Riverside Lowlands Bioregion characterizes areas east of the Santa Ana Mountains Bioregion, south of the Riverside/San Bernardino County line, west of Diamond Valley Lake, Lake Skinner, and Gilman Hot Springs, and north of the Riverside/San Diego County line. This bioregion encompasses Estelle Mountain, Lake Mathews, Reche Canyon/Badlands, the San Jacinto Valley, Gavilan Hills, Lakeview Mountains, and French Valley. The Riverside Lowlands Bioregion generally occurs at elevations below 2,000 feet and is characterized by Riversidean sage scrub and annual grasslands. The relatively arid climate is in part the result of the rain shadow effect cast by the Santa Ana Mountains. A high level of disturbance and urbanization is noted within this bioregion.

San Jacinto Foothills Bioregion

The San Jacinto Foothills Bioregion generally includes areas north of SR-79, east of the Riverside Lowlands Bioregion and west of the San Jacinto Mountains Bioregion. This bioregion encompasses Vail Lake, Sage, and Cactus Valley. The San Jacinto Foothills Bioregion occurs at elevations of 2,000 to 3,000 feet and is dominated by Riversidean sage scrub and xeric chaparral associations. This bioregion receives less frequent frost and snow than the mountainous areas. This bioregion has not been heavily disturbed or urbanized.

Agua Tibia Mountains Bioregion

The Agua Tibia Mountains Bioregion extends south from SR-79 to the Riverside/San Diego County line. It encompasses the Agua Tibia Mountains and generally occurs at elevations above 2,000 feet. This bioregion supports Diegan coastal sage scrub, mesic chaparral, and sparse coniferous vegetation. The Agua Tibia Mountains Bioregion has not been heavily disturbed or urbanized.

Desert Transition Bioregion

The Desert Transition Bioregion is located in the southeastern portion of the proposed Plan Area and encompasses the Cahuilla Indian Reservation and Lake Riverside area. The Desert Transition Bioregion generally occurs at elevations above 3,000 feet and is arid and desert-influenced. This bioregion supports red shank chaparral, big basin sage scrub, and semidesert succulent scrub habitats. This bioregion has not been heavily disturbed or urbanized.

San Bernardino Mountains Bioregion

The San Bernardino Mountains Bioregion is located in the northwestern portion of the proposed Plan Area and encompasses areas north of I-10 within the Calimesa, Beaumont, and Banning area; it generally occurs at elevations above 3,000 feet. This bioregion supports coniferous forests, montane chaparral, and broad-leaved forest. The San Bernardino Mountains Bioregion is floristically distinct from the San Jacinto Mountains Bioregion. This bioregion has not been heavily disturbed or urbanized.

San Jacinto Mountains Bioregion

The San Jacinto Mountains Bioregion occurs in the eastern portion of the proposed Plan Area and encompasses the San Bernardino National Forest, Pine Cove, Idyllwild, and upper San Jacinto River and Bautista Canyon Creek. This bioregion supports coniferous forests, montane chaparral, and broad-leaved forest; it generally occurs at elevations above 3,000 feet. The San Jacinto Mountains Bioregion is floristically distinct from the San Bernardino Mountains Bioregion.

3.1.3 Vegetation Communities

The proposed MSHCP vegetation communities map was created in 1995 by PSBS and mapped by KTU+A. For the purpose of analysis, the 1995 vegetation communities were subsequently generalized to ensure consistency in mapping scale across the proposed Plan Area. In addition to the vegetation communities map, PSBS and KTU+A created a coastal sage scrub habitat quality map for the purpose of regional reserve planning for the California gnatcatcher. Other vegetation mapping efforts include a riparian map coverage created by UCR in 2000. The proposed MSHCP vegetation map described above incorporates 50 vegetation community classifications. For the purpose of proposed MSHCP planning and analysis, the 50 classifications were collapsed to 14; both classes of categories are summarized in Table 3A.

Table 3A - Summary of Collapsed and Uncollapsed Vegetation Communities Classifications
Collapsed Vegetation Communities Classifications	Uncollapsed Vegetation Communities Classifications
Montane Coniferous Forest	Jeffrey Pine
	Lodgepole Pine
	Lower Montane Coniferous Forest
	Mixed Evergreen Forest
	Southern California White Fir
	Subalpine Coniferous
Woodland and Forests	Black Oak Forest
	Broadleaved Upland Forest
	Coast Live Oak Woodland
	Dense Engelmann Oak Woodland
	Oak Woodland
	Peninsular Juniper Woodland and Scrub
Coastal Sage Scrub	Coastal Scrub
	Diegan Coastal Sage Scrub
	Riversidean Sage Scrub
Riversidean Alluvial Fan Sage Scrub	Disturbed Alluvial
	Riversidean Alluvial Fan Sage Scrub
Desert Scrub	Big Sagebrush Scrub
	Colorado Desert Wash Scrub
	Semidesert Succulent Scrub
	Sonoran Desert Scrub
Chaparral	Chamise Chaparral
	Chaparral
	Red Shank Chaparral
	Semi-Desert
Playas and Vernal Pools	Alkali Playa
	Southern Interior Basatt Vernal Pool
	Vernal Pool
Grassland	Non-native Grassland
	Valley and Foothill Grassland
Riparian Scrub, Woodland, Forest	Arundo/Riparian Forest
	Montane Riparian Forest
	Montane Riparian Scrub
	Mule Fat Scrub
	Riparian Forest
	Riparian Scrub
	Southern Cottonwood/Willow Riparian
	Southern Sycamore/Alder Riparian Woodland
	Southern Willow Scrub
	Tamarisk Scrub
Meadows and Marshes	Meadow (Montane)
	Wet Montane Meadow
	Coastal and Valley Freshwater Marsh Marsh
Cismontane Alkali Marsh	Cismontane Alkali Marsh
Water	Open Water/Reservoir/Pond
Developed or Disturbed Land	Residential/Urban/Exotic
Agriculture	Dairy and Livestock Feed Yards
	Field Croplands
	Grove/Orchard

The proposed MSHCP Plan Area encompasses approximately 1.26 million acres with approximately 871,000 acres (69 percent) supporting natural vegetation. The 14 vegetation communities within the proposed Plan Area (Table 3B) include chaparral (434,950 acres), cismontane alkali marsh (1,260 acres), coastal (Diegan and Riversidean) sage scrub (156,450 acres), desert scrubs (14,570 acres), native and non-native grassland (154,140 acres), meadows and marshes (1,020 acres), montane coniferous forest (29,910 acres), peninsular juniper woodland and scrub (1,080 acres), playas and vernal pools (7,910 acres), riparian scrub/woodland/forests (15,030 acres), Riversidean alluvial fan sage scrub (7,940 acres), open water (12,210 acres), woodlands and forests (34,300 acres), and unknown (1,350 acres). In addition, approximately 169,480 acres are in agriculture, and the remaining 218,260 acres are considered disturbed or developed land. Section C of the proposed MSHCP Reference Document, in Volume II of the proposed MSHCP, contains detailed habitat accounts describing the biogeography, range and distribution, vegetation characteristics, species composition, physical environment, ecosystem processes, community relationships, and threats for each vegetation community within the proposed Plan Area. A brief description of each vegetation community is provided below.

Table 3B - Acreage and Proportional Distribution of Vegetation Communities within the Proposed MSHCP Plan Area
Vegetation Type	Total Acres in Plan Area	Percent of Total Vegetation
Agriculture	169,480	13.5%
Chaparral	434,950	35.0%
Cismontane Alkali Marsh	1,260	0.1%
Coastal Sage Scrub	156,450	12.0%
Desert Scrub	14,570	1.2%
Grassland	154,140	12.2%
Meadows and Marshes	1,020	0.08%
Montane Coniferous Forest	29,910	2.4%
Playas and Vernal Pools	7,910	0.6%
Riparian Scrub, Woodland, and Forest	15,030	1.2%
Riversidean Alluvial Fan Sage Scrub	7,940	0.6%
Water	12,210	1.0%
Woodlands and Forests	34,300	2.7%
Developed or Disturbed Land	218,260	17.3%
Unknown	1,350	0.11%
TOTALS	1,258,750	100%

Agriculture

Agricultural lands include areas occupied by dairies and livestock feed yards or areas that have been tilled for use as croplands or groves/orchards. Approximately 13 percent of the MSHCP Plan Area (169,480 acres) consists of agricultural lands. The largest areas of dairy and livestock feed yards are located north of San Jacinto and north of Juniper Flats in the communities of Lakeview, Mystic Lake, Nuevo, southeast Perris, Eastvale, Lake Norconian off Bellegrave Avenue, Norco, and in Glen Avon. Field croplands are mapped extensively throughout the proposed Plan Area. The largest areas are around the following: State Route 371 (SR-371) in the vicinity of Anza; in an eastwest strip from Murrieta Hot Springs, through French Valley; Antelope Valley, Paloma Valley, Menifee Valley, Winchester, and Domenigoni Valley to West Hemet; the Diamond Valley area; and in Eastvale. The largest area of grove/orchard is in Santa Rosa East between Gavilan Mountain and Mesa de Colorado. Agricultural lands are further discussed in Sections 3.2 and 4.2.

Chaparral

Chaparral vegetation is the most abundant and widespread vegetation type in western Riverside County, covering approximately 35 percent (434,950 acres) of the proposed Plan Area. Large contiguous stands of chaparral occur along the Santa Ana Mountains in the western portion of the proposed Plan Area, and along the San Bernardino, San Jacinto, and Agua Tibia Mountains in the eastern and southern portions. Although chaparral is less common than other vegetation types in the central lowlands of Riverside County, three large chaparral-dominated areas occur on steeper lands near the Gavilan Hills-Gavilan Plateau-Meadowbrook Region, the Lakeview Mountains-Double Butte area, and the Sedco Hills-Hogbacks area.

Chaparral is a shrub-dominated vegetation community that is composed largely of evergreen species that range from 3 to 12 feet in height (Keeley, 2000). The most common and widespread species within chaparral is chamise (Adenostoma fasciculatum) (Hanes, 1971). Other common shrub species include manzanita (Arctostaphylos spp.), wild-lilac (Ceanothus spp.), oak (Quercus spp.), redberry (Rhamnus spp.), laurel sumac (Malosma laurina), mountain-mahogany (Cercocarpus betuloides), toyon (Heteromeles arbutifolia), and mission manzanita (Xylococcus bicolor) (Holland, 1986). Soft-leaved subshrubs are less common in chaparral than in coastal sage scrub (see below) but occur within canopy gaps of mature stands (Holland, 1986; Keeley and Keeley, 1988; Sawyer and Keeler-Wolf, 1995). Common species include California buckwheat (Eriogonum fasciculatum), sages (Salvia spp.), California sagebrush (Artemisia californica), and monkeyflower (Mimulus spp.). In addition, herbaceous species, including deerweed (Lotus scoparius), nightshade (Solanum spp.), Spanish bayonet (Yucca whipplei), rock-rose (Helianthemum scoparium), onion (Allium spp.), soap plant (Chlorogalum spp.), bunch grasses (Nassella spp., and Melica spp.), wild cucumber (Marah spp.), bedstraw (Galium spp.), and lupine (Lupinus spp.) are also present (Holland, 1986; Keeley and Keeley, 1988; Sawyer and Keeler-Wolf, 1995 ).

Cismontane Alkali Marsh

Cismontane alkali marsh habitat is scattered sparsely over the western Riverside County region, occupying approximately 0.1 percent (1,260 acres) of the proposed Plan Area. Cismontane alkali marsh was mapped in two general localities along Cahuilla Creek south of Anza and upstream from Lake Mathews along the Colorado River aqueduct.

Typical cismontane alkali marsh species include yerba mansa (Anemopsis californica), saltgrass (Distichlis spicata), alkali-heath (Frankenia salina), cattails (Typha spp.), common pickleweed (Salicornia virginica), rushes (Juncus spp.), marsh flea-bane (Pluchea odorata), and sedges (Carex spp.) (Holland, 1986).

Coastal Sage Scrub

Coastal sage scrub is distributed throughout western Riverside County, occupying approximately 12 percent (156,450 acres) of the proposed Plan Area (PSBS, 1995). It occurs from the eastern slopes of the Santa Ana Mountains to elevations in the San Jacinto Mountains less than 5,000 feet. Sage scrub often is distributed in patches throughout its range. Over a scale of several miles, it can be found in diverse vegetation community mosaics with other plant communities, particularly grassland and chaparral, and oak/riparian woodland in wetter areas. In western Riverside County, coastal sage scrub is found both in large contiguous blocks scattered throughout the County as well as integrated with chaparral and grasslands.

Coastal sage scrub is dominated by a characteristic suite of low-statured, aromatic, drought-deciduous shrubs, and subshrub species. Composition varies substantially depending on physical circumstances and the successional status of the vegetation community; however, characteristic species include California sagebrush, California buckwheat, laurel sumac, California encelia (Encelia californica), and several species of sage (e.g., Salvia mellifera, S. apiana) (Holland, 1986; Sawyer-Wolf, 1995). Other common species include brittlebush (Encelia farinosa), lemonadeberry (Rhus integrifolia), sugarbush (Rhus ovata), yellow bush penstemon (Keckiella antirrhinoides), Mexican elderberry (Sambucus mexicana), sweetbush (Bebbia juncea), boxthorn (Lycium spp.), shore cactus (Opuntia littoralis), coastal cholla (Opuntia prolifera), tall prickly-pear (Opuntia oricola), and species of Dudleya.

Desert Scrub

Desert scrub, including big sagebrush scrub and Sonoran desert scrub, occurs mostly in the southeastern portion of the proposed Plan Area. Desert scrub occupies approximately 1.2 percent (14,570 acres) of the proposed Plan Area. Large acreages of the vegetation community occur north and south of SR-371 within Tule Valley, Culp Valley, Wilson Creek, Cahuilla, the Ramona Indian Reservation, the Community of Anza, and east of Aguanga and Lake Riverside.

Desert scrub is typically composed of shrubs such as big sagebrush (Artemisia tridentata), bitterbrush (Purshia tridentata), rubber rabbit-bush (Chrysothamus nauseosus), yellow rabbitbrush (Chrysothamus viscidiflorus), black bush (Coleogyne ramosissima), Mormon-tea (Ephedra viridis), horsebrush (Tetradymia canescens), plateau gooseberry (Ribes velutinum), hopsage (Grayia spinosa), burro weed (Ambrosia dumosa), brittlebush, crucifixion-thorn (Canotia holacantha), ocotillo (Fouquieria splendens), and creosote scrub (Larrea tridentata) (Holland, 1986). The herbaceous cover generally is dominated by a mixture of perennial bunch grasses, such as ricegrass (Achnatherum hymenoides), needle-and-thread (Stipa comata), letterman’s needlegrass (Stipa lettermanii), needlegrass (Stipa occidentalis and Stipa thurberiana), desert needlegrass (Stipa speciosa), one-sided bluegrass (Poa secunda), bluebunch wheatgrass (Agropyron spicata), and Great Basin wild rye (Leymus cinereus). Annual grasses and forbs may also occur within big sagebrush scrub. Cheatgrass (Bromus tectorum), an introduced annual grass, has become the dominant herbaceous species in many areas.

Grasslands

Grasslands occur throughout most of western Riverside County and cover approximately 12.2 percent (154,130 acres) of the proposed Plan Area. Two general types of grasslands occur in Southern California: (1) non-native dominated, primarily annual grassland (“non-native grassland”); and (2) native dominated, perennial grassland (“valley and foothill grassland”) (Heady, 1977; Keeley, 1989; Sims and Risser, 2000). The only valley and foothill grasslands mapped within the proposed Plan Area are distributed over approximately 0.2 percent (2,700 acres) of the proposed Plan Area on the Santa Rosa Plateau. Non-native grasslands occur throughout the majority of the proposed Plan Area (11.6 percent), usually within close proximity to urbanized or agricultural land uses. Large patches of non-native grasslands occur in the Riverside Lowlands near March Air Reserve Base (ARB), Lake Mathews, Lake Perris, Lake Elsinore, near Banning, Cahuilla, and in the Terwilliger Valley south of Anza.

Valley and foothill grasslands typically contain the perennial bunch grasses Nassella pulchra and Nassella lepida. Lesser amounts of other native grasses, such as Melica spp., Leymus spp., Muhlenbergia spp., and beard grass (Bothriochloa barbinodis), may also be present. In addition, non-native grasses or forbs may be present to varying degrees. Native herbaceous plants commonly found within valley and foothill grasslands include yellow fiddleneck (Amsinckia menziesii), common calyptridium (Calyptridium monardum), suncup (Camissonia spp.), Chinese houses (Collinsia heterophylla), California poppy (Eschcholzia californica), tarweed (Hemizonia spp.),

coast goldfields (Lasthenia californica), common tidy-tips (Layia platyglossa), Lupinus spp., Plagiobothrys spp., blue dicks (Dichelostemma capitata), Muilla spp., blue-eyed grass (Sisyrinchium bellum), and Dudleya spp. (Holland, 1986; Keeley, 1989; Sims and Risser, 2000).

Non-native grasslands are likely to be dominated by several species of grasses that have evolved to persist in concert with human agricultural practices: slender oat (Avena barbata), wild oat (Avena fatua), fox tail chess (Bromus madritensis), soft chess (Bromus hordeaceus), ripgut grass (Bromus diandrus), barley (Hordeum spp.), rye grass (Lolium multiflorum), English ryegrass (Lolium perrene), rat-tail fescue (Vulpia myuros), and Mediterranean schismus (Schismus barbatus) (Jackson, 1985; Sims and Risser, 2000).

Meadows and Marshes

Approximately 1,020 acres of meadow and marsh vegetation communities, including coastal and valley freshwater marsh, undifferentiated marsh, and wet montane meadow, exist within the proposed Plan Area, comprising 0.04 percent of the proposed Plan Area. Occurrences of this vegetation community have been mapped in the Prado Basin in the Santa Ana River Valley, on the Santa Ana River near Pedley, north of Lake Elsinore in Walker Canyon, near San Jacinto, along the shores of Lake Skinner and Vail Lake, and adjacent to the cismontane alkali marsh on Cahuilla Creek. Undifferentiated marsh was mapped in three locations, including the shore of Lake Mathews, near Mystic Lake, and upstream from Vail Lake along Temecula Creek in the Aguanga Valley. Wet montane meadow was mapped in the San Jacinto Mountains in the San Bernardino National Forest, primarily within the vicinity of Hemet Lake.

Meadow and marsh vegetation communities occur in both flowing and still water. This vegetation community includes cattails, bulrushes, sedges, spike rushes, flatsedges (Cyperus spp.), smartweed (Polygonum spp.), watercress (Rorippa spp.), yerba mansa, and also contains perennial and biennial herbs (e.g., Oenothera spp., Polygonum spp., Lupinus spp., Potentilla spp., and Sidalcea spp.) and grasses (e.g. Agrostis spp., Deschampsia spp., and Muhlenbergia spp.) (Barbour and Major, 1977; Sawyer and Keeler-Wolf, 1995; Stephenson and Calcarone, 1999; Holland and Keil, 1995). Rooted aquatic plant species with floating stems and leaves also may be present, such as pennywort (Hydrocotyle spp.), water smartweed (Polygonum amphibium), pondweeds (Potamogeton spp.), and water-parsley (Oenanthe sarmentosa). Wet montane meadows that dry out by mid-summer have a higher percentage of perennial grasses than meadows that remain moist during the entire growing season (Holland and Keil 1995).

Montane Coniferous Forest

Montane coniferous forest, including Jeffrey pine, lodgepole pine forest, lower montane coniferous forest, mixed evergreen forest, Southern California white fir forest, and subalpine coniferous forest, occupies 2.4 percent (29,900 acres) of the proposed MSHCP Plan Area. It occurs within the San Jacinto Mountains, Agua Tibia, Cleveland National Forest, and Santa Rosa Mountains.

Montane coniferous forest is dominated by Jeffrey pine (Pinus jeffreyi), ponderosa pine (Pinus ponderosa), Coulter pine (Pinus coulteri), lodgepole pine (Pinus contorta ssp. murrayanna), limber pine (Pinus flexilis), bigcone Douglas-fir (Pseudotsuga macrocarpa), Pacific madrone (Arbutus menziesii), bigleaf maple (Acer macrophyllum), Rocky Mountain white fir (Abies concolor var. concolor), and sugar pine (Pinus lambertiana). Common understory shrubs include manzanita, California lilac (Ceanothus spp.), chinquapin (Chrysolepis), currant (Ribes spp.), and dwarf mistletoe (Arceuthobium campylopodum). The herbaceous layer is composed of morning-glory (Calystegia occidentalis ssp. fulcrata), sedge (Carex multicaulis), clarkia (Clarkia rhomboidea), and mountain-heather (Phyllodoce breweri).

Playas and Vernal Pools

These vegetation communities comprise 0.6 percent (7,910 acres) of the proposed Plan Area. Playas and vernal pools are found in western Riverside County in the San Jacinto Valley/Perris Basin and on the Santa Rosa Plateau.

Vernal pools are ephemeral wetlands that form in shallow depressions underlain by a substrate near the surface that restricts the downward percolation of water. Depressions in the landscape fill with rainwater and runoff from adjacent areas during the winter and may remain inundated until spring or early summer, sometimes drying more than once during the wet season. Smaller pools can fill and dry, and larger pools can hold water longer and may in the deeper portions support species that are more representative of freshwater marshes. Vernal pools are well-known for their high level of endemism (Stone, 1989) and abundance of rare, threatened, or endangered species (Sawyer and Keeler-Wolf, 1995). Many vernal pools are characterized by concentric rings of plants that flower sequentially as the pools dry. Vernal pools are dominated by native annual plants, with low to moderate levels of perennial herbaceous cover. Common vernal pool plant species in western Riverside County include woolly marbles (Psilocarphus brevissimus), toad rush (Juncus bufonius), and spike rush. In addition, the following sensitive or listed plant species are found in one or more of these pools: California Orcutt grass (Orcuttia californica), Coulter’s goldfields (Lasthenia glabrata ssp. coulteri), little mousetail (Myosurus minimus ssp. apus), spreading navarretia (Navarretia fossalis), low navarretia (Navarretia prostrata), Orcutt’s brodiaea (Brodiaea orcuttii), thread-leaved brodiaea (Brodiaea filifolia), Parish’s brittlescale (Atriplex parishii), Parish’s meadowfoam (Limnanthes gracilis ssp. parishii), San Diego button-celery (Eryngium aristulatum var. parishii), Wright’s trichocoronis (Trichocoronis wrightii var. wrightii), San Jacinto Valley crownscale (Atriplex coronata var. notatior), and smooth tarplant (Centromadia pungens ssp. laevis) (Sawyer and Keeler-Wolf, 1995). The Santa Rosa Plateau fairy shrimp (Linderiella santarosae) only occurs in western Riverside county, which is also the location of the southernmost record for the vernal pool fairy shrimp (Branchinecta lynchi) (Eriksen and Belk, 1999).

Riparian Forest, Woodland, and Scrub

Riparian vegetation, including forest, woodland, and scrub subtypes, is distributed in waterways and drainages throughout much of western Riverside County, covering approximately 1.2 percent (15,030 acres) of the proposed Plan Area. Southern cottonwood/willow forest makes up the largest proportion of the riparian vegetation in the proposed Plan Area, comprising nearly one-half (6,610 acres) of the acreage. Most of the southern cottonwood/willow forest vegetation community occurs along the Santa Ana River drainage from Lake Evans to beyond the Prado basin, along the San Gorgonio River north of Banning and along Temecula Creek east of Vail Lake. Additional types of riparian vegetation can be found along the San Gorgonio River north of Banning (montane riparian forest), Temescal Canyon Wash and its tributaries (riparian scrub and mule fat scrub), the stream channels within the San Mateo Canyon watershed (riparian Riparian communities typically consist of one or more deciduous tree species with an assorted understory of shrubs and herbs (Holland and Keil, 1995). Depending on community type, a riparian community may be dominated by any of several trees/shrubs, including box elder (Acer negundo), bigleaf maple, coast live oak (Quercus agrifolia), white alder (Alnus rhombifolia), sycamore (Platanus racemosa), Fremont’s cottonwood (Populus fremontii), California walnut (Juglans californica), Mexican elderberry, wild grape (Vitis girdiana), giant reed (Arundo donax), mule fat (Baccharis salicifolia), tamarisk (Tamarix spp.), or any of several species of willow (Salix spp.). In addition, various understory herbs may be present, such as saltgrass, wild cucumber (Marah macrocarpus), mugwort (Artemisia douglasiana), stinging nettle (Urtica dioica), and poison oak (Toxicodendron diversilobum).

Riversidean Alluvial Fan Sage Scrub

Riversidean alluvial fan sage scrub occurs throughout many drainages in the proposed Plan Area and comprises approximately 0.6 percent (7,940 acres) of the proposed Plan Area. Large acreages of the vegetation occur in the following areas: on the Santa Ana River near Lake Evans in the City of Riverside; along the San Gorgonio River and tributaries near Banning; on the San Jacinto River from the National Forest to the Soboba Indian Reservation; near Temecula along Temecula Creek; the Aguanga area; Bautista Creek south of Hemet; and near Murrieta and Glen Ivy in the Temescal Valley.

Riversidean alluvial fan sage scrub is a Mediterranean shrubland type that occurs in washes and on gently sloping alluvial fans. Alluvial scrub is made up predominantly of drought-deciduous soft-leaved shrubs, but with significant cover of larger perennial species typically found in chaparral (Kirkpatrick and Hutchinson, 1977). Scalebroom (Lepidospartum squamatum) generally is regarded as an indicator of Riversidean alluvial scrub (Smith, 1980; Hanes, et al., 1989). In addition to scalebroom, alluvial scrub typically is composed of white sage (Salvia apiana), redberry (Rhamnus crocea), California buckwheat, Spanish bayonet, California croton (Croton californicus), cholla (Opuntia spp.), tarragon (Artemisia dracunculus), yerba santa (Eriodictyon spp.), mule fat, and mountain-mahogany (Hanes, et al., 1989; Smith, 1980). Annual species composition has not been studied but is probably similar to that found in understories of neighboring shrubland vegetation. Two sensitive annual species are endemic to alluvial scrub vegetation in the proposed Plan Area: slender-horned spineflower (Dodecahema leptocerus) and Santa Ana River woollystar (Eriastrum densifolium ssp. sanctorum).

Water

Approximately 1.0 percent (12,210 acres) of the proposed Plan Area consists of open water habitat. Open water was mapped at Vail Lake, Lake Skinner, Diamond Valley Lake, Lake Perris, Mystic Lake, Canyon Lake, Lake Elsinore, Lee Lake, Lake Mathews, Hemet Lake, portions of the San Jacinto River, and portions of the Santa Ana River, as well as various small ponds, private reservoirs, and portions of stream channels.

Open water habitat typically is unvegetated due to a lack of light penetration. However, open water may contain suspended organisms such as filamentous green algae, phytoplankton (including diatoms), and desmids (Grenfell, 1988). Floating plants such as duckweed (Lemna spp.), water buttercup (Ranunculus aquatilis), and mosquito fern (Azolla filiculoides) also may be present (Holland and Keil, 1995). Open water includes inland depressions, ponds, lakes, reservoirs, and stream channels containing standing water and often occur in conjunction with riparian and upland vegetation communities. Depth may vary from hundreds of feet to a few inches.

Woodlands and Forests

The proposed Plan Area supports approximately 34,300 acres (2.7 percent of the proposed Plan Area) of woodlands and forests composed of black oak forest, broad-leaved upland forest, oak woodland, and peninsular juniper woodland vegetation communities. Woodland and forest vegetation communities are dominated by Englemann oak (Quercus englemannii), coast live oak, canyon live oak (Quercus chrysolepis), interior live oak (Quercus wislizenii), and black oak (Quercus kelloggii) in the canopy, which may be continuous to intermittent or savannah-like. Four-needle pinyon (Pinyon quadrifolia), single-leaf pinyon pine (Pinus monophylla) and California juniper (juniperus californica) are the canopy species of peninsular juniper woodland, which most commonly occurs in Southern California, forming a scattered canopy from 9 to 45 feet tall (Sawyer and Keeler-Wolf 1995; Holland and Keil 1995).

Many understory plants in oak woodlands are shade tolerant and include wild blackberry (Rubus ursinus), snowberry (Symphoricarpos mollis), California walnut, California-lilac (ceanothus spp.), Rhus spp., currant, toyon, California bay (Umbellularia californica), Engelmann oak, manzanita (Arctostaphylos spp.), laurel sumac, poison oak, and herbaceous plants including bracken fern (Pteridium aquilinum), polypody fern (Polypodium californicum), fiesta flower (Pholistorma auritum), and miner’s lettuce (Claytonia perfoliata) (Holland and Keil, 1995; Sawyer and Keeler-Wolf, 1995; Thorne, 1976; Brown, 1982). Munz and Keck (1949) identify similar species for this vegetation community and include a variety of grasses and soft shrubs that also are commonly found. This vegetation community can occur on all aspects, on stream sides, canyon bottoms, and flat to very steep topography. Woodlands and forests are known to occur throughout the proposed Plan Area.

Developed or Disturbed Land

Approximately 218,260 acres (17.3 percent) of developed or disturbed lands occur within the proposed Plan Area. Developed or disturbed lands consist of areas that have been disced, cleared, or otherwise altered. Developed lands may include roadways, existing buildings, and other structures. The largest areas of developed land are in the cities of Temecula, Murrieta, Lake Elsinore, Canyon Lake (including the surrounding unincorporated communities of Meadowbrook, Alberhill, El Cariso, and Lakeland Village), Hemet (including the surrounding unincorporated communities of East Hemet and Valle Vista), in Moreno Valley, and along the SR-91 corridor from Riverside through Corona and Norco. More medium-sized tracts of developed land are located in the communities of Canyon Lake (including Quail Valley, Sun City, and Homeland), in Perris along I-215 (including Mead Valley, Gavilan Hills, and Woodcrest), Beaumont, Banning (including Cherry Valley), and Calimesa. Small and scattered occurrences include the southeast portion of the proposed Plan Area along SR-371 in the unincorporated communities of Terwilliger Valley, Sage, Aguanga and Anza, east of the City of Temecula, and in Sedco Hills. Disturbed lands may include ornamental plantings for landscaping, escaped exotics, or ruderal vegetation dominated by non-native, weedy

Unknown

Approximately 1,350 acres within the proposed Plan Area were not classified into a vegetation community during the 1995 PSBS and KTU+A mapping effort.

3.1.4 Species Considered for Conservation in the Proposed MSHCP

Table 2G in Section 2.0 lists the 146 species that were considered to receive coverage under the proposed MSHCP. As shown in Table 2E, the initial list of species considered for conservation included 247 species identified for consideration by the proposed MSHCP Advisory Committee in collaboration with the Wildlife Agencies. Early in the planning process, it was determined that sufficient information was not available for many of these species to proceed with conservation planning. The initial list of 247 species was reduced to 165 species as part of the August 9, 1999 Draft MSHCP Proposal prepared by DUDEK. The list was further refined to 146 species as the proposed MSHCP planning process proceeded, and information needed to proceed with conservation planning could not be obtained for certain species. Several species were added to the list during this process as suggested by stakeholders such as the Wildlife Agencies and the California Native Plant Society (CNPS). Species added included great blue heron, Dulzura kangaroo rat, Aguanga kangaroo rat, and six plant species.

Of the 146 covered species addressed in the proposed MSHCP, 118 species are considered to be adequately conserved. The remaining 28 covered species will be considered to be adequately conserved when certain conservation requirements are met as identified in the species-specific conservation objectives for those species (speciesspecific conservation objectives for the 146 covered species are presented in Section 9.0 of the proposed MSHCP). Specific survey requirements are included in the speciesspecific conservation objectives presented in Section 9.0 of the proposed MSHCP and in Section 4.1 of this EIR/EIS. A complete summary of MSHCP species survey requirements is also provided in Appendix E of Volume I of the MSHCP.