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Home My WebLink AboutCT 02-07; EMERALD POINT ESTATES; BIOLOGICAL IMPACT ASSESSMENT; 1998-12-22'I Anita M. Hayworth Biological Consultant 1235 Meadow Wood Place Encinitas, CA 92024 22 December 1998 Mr. Jack Henthorn Jack Henthorn and Associates 5375 Avenida Encinas Suite D Carlsbad, CA 92008 e· Re: Biological Impact Assessment of the BCS Property, Carlsbad, CA Dear Mr. Henthorn, A reconnaissance level survey was conducted of the approximately 17 ~acre BCS property on 4 January 1997. A focussed survey for rare plants was conducted on 13 April 1997. The property is located south of Palomar Airport Road, and west of E1 Camino Real, Carlsbad, California. Laurel Tree Road and the Laurel Tree Apartment development borders the western edge of the property. Cobblestone Sea Village (Mar Brisa) development is located to the south and east, and agricultural land borders the north. The purpose of the survey was to determine the vegetation communities present on the site, the approximate boundaries of the vegetation communities, the 'sensitive resources. that may be present and require additional surveys and to describe and quantify those impacts associated with the proposed project and establish mitigation measures. A focussed survey was conducted for the San Diego thorn, mint (Acanchomincha ilicifolia) which was previously recorded' for the site. All areas of suitable conditions were searched and some of the areas that have been in active agriculture were also searched. 2.0 MEmODS AND SURVEY LIMITATIONS Data regarding biological resources present on the project site were obtained through a review of pertinent literature and through field recoimaissance. 2.1 FIELD RECONNAISSANCE Biological surveys of the BCS property were conducted by biologist Anita M. Hayworth Ph.D. during January and April 1997. Dates of the surveys were] anuary 4 and April 13. All surveys were conducted by foot under favorable weather conditions,. and all areas of the property were visited and inventoried for biotic components. The time of the surveys was generally between 0900 and 1100 for 2 hours for each visit. Weather' conditions were typically mild with temperatures ranging from 61 to 68 of, windspeed from 1 ~ 8 MPH, and skies clear. Plant communities were mapped in the field onto 200~scale (1" =200') aerial photographs of the site. The aerial photographs were from Aerial Fotobank, dated 1 March 1994. Plant community classifications used in this report follow Holland (1986), with modifications to accommodate the lack of conformity of the observed communities to those of Holland. Locations of rare or sensitive plant and wildlife species also were mapped. 3.0 REsULTS 3.1 PLANT COMMUNITIES Based on species composition and general physiognomy, five vegetation communities are present onsite as depicted in the accompanying vegetation mapping: disturbed (agriculture and , roadways), coastal sage scrub, southern mixed chaparral, non~native grassland, valley needlegrass grassland. These plant communities are discussed below. Coastal Sage Scrub (4.9 acres) Coastal sage scrub is a native plant community characterized by a variety of soft, low, aromatic, drought~deciduous shrubs, such as California sagebrush (Artemisia califarnica) flat~cop buckwheat (Eriogonum fasciculatum), California bush sunflower (Encelia califarnica), and sages (Salvia spp.), with scattered evergreen shrubs, including lemonadeberry (Rhus integrifolia), laurel sumac (Malosma laurina), and coyon (Heteromeles arbutifolia). It typically develops on south~facing slopes and other xeric situations. Coastal sage scrub is considered a sensitive habitat type because of its depleted nature and the large number of sensitive plant and wildlife species that it supports. Coastal sage is the focus of the present State of California's Natural Communities Conservation Program (NCCP). Onsite, coastal sage scrub occurs along the west~facing slope as a continuous band of relatively undisturbed and high~quality habitat. The patch of habitat is almost a continuous patch connected to existing habitat offsite to the south, but is broken by the presence of Cobblestone Road. Southern Mixed Chaparral (0.8 acres) Southern mixed chaparral is a drought~ and fire~adapted community ofbroad~leafed shrubs 1.5~ 3.0 m tall, typically forming dense impenetrable stands. It develops primarily on mesic north~ facing slopes and in canyons. This association is typically a mixture of chamise (Adenost6ma fasciculatum) I mission manzanita (Xylococcus bicolor), ceanothus (Ceanathus -spp.), scrub oak (Quercus dumosa), laurel sumac, and black sage. Within the BCS property, southern mixed chaparral is present on the north~facing steep slopes. Page 2 Valley Needlegrass Grassland (0.6 acres) Valley neecilegrass grassland is a native community dominated by large tussocks of perennial native neecilegrass (Nasella spp.). The habitat is open and typically supports a variety of introduced grasses and forbs. Other species typically associated with native grasslands in southern California include blue-eyed grass (Sisyrinchium bellum), wild onion (Allium sp.) , blue dicks (DichelosteTnma capitatum), Cleveland's shooting-star (Dodecatheon clevelandii)., dot-seed plantain (Plantago erecta), and purple owl's-clover (Castilleja ex.serta). Several small patches of native grassland occur on the slopes of the property. Non-native Grassland (0.9 acres) Where native plant communities have been subject to repeated or severe disturbance, the habitat frequently reverts to annual or non-native grassland. These areas usually are dominated by annual grasses, such as bromes (Bromus spp.) and wild oats (Avena spp.), and other disturbance- tolerant species such as filarees (Erodium spp.), telegraph weed (Hecerocheca grandifiora), and doveweed (E remocarpus sedgerus). Several patches of non-native grassland are located onsite. Disturbed/Agriculture Land (10.14 acres) A large portion of the property has been, and continues to be, used for agriculture. Other areas onsite may also be used for agriculture either currently or in the past. Other areas of disturbed land are composed of existing roadways. This activity obviously inhibits the succession of native plant communities. While some animal species such as CalifOrnia ground squirrel (Spermophilus beecheyi) and cottontail rabbit (Sylvilagus sp.) may use these 'areas, in general, agricultural and disturbed lands represent low quality habitat for native species. 3.2 SENSITIVE BIOLOGICAL RESOURCES The following resources are discussed in this section: (1) plant present in the project vicinity that are given special recognition by federal, state, or local conservation agencies and organizations owing to declining, limited, or threatened populations, that are the results, in most cases, of habitat reduction; and (2) habitat areas that are unique, are of relatively limited distribution, or are of particular value to wildlife. Sources used for determination of sensitive biological resources are as follows: plants --USFWS (1990, 1993), CDFG (1987), CNDDB, and Skinner and Pavlik (1995); and habitats --CNDDB. Sensitive Plant Species Sensitive plant species observed on the project site include San Diego thorn-mint, a California Department of Fish and Game endangered species. This species is discussed below. Acanthomintha ilicifolia -San Diego thorn-mint USFWS: ProposedEndangered Page 3 CDFG: Endangered CNPS: List IB, 3~3~2 San Diego thom~mint is restricted in distribution to San Diego County and northern Baja California. It is best detected during its spring blooming period (April~Mp.y). This annual plant occurs on clay lenses of several geologic origins on mesas and slopes below 300 m (965 ft) elevation, and is associated with Diegan coastal sage scrub, chaparral and native grassland. In San Diego County, the species is known from Encinitas and San Marcos south to Sweetwater and Otay Lakes (Beauchamp 1986). The species is also known from higher elevations on McGinty Mountain (Wier and Brown, in prep.) and Poser Mountain (Wier, pers. obs.). An initial search was conducted on 4 January 1997 for presence and extent of the San Diego thorn~mint, a California listed endangered plant species. This plant species was recorded for the site during a previous biological survey. The plant was not observed during this visit to the site, however, these negative results are questionable due to the time of year of the survey: San Diego thorn,mint is an annual plant that does not appear until after substantial spring rains. A second visit focussed on surveying for San Diego thorn~mint was conducted on 13 April 1997, the appropriate time of year for detecting this species. Other botanists in the San Di,ego region had reported observing it at that time in other areas of the County. The survey revealed that a small population of San Diego thorn,mint is present on the site. It contains approximately 150,200 individuals scattered in a relatively confined area. The area is at approximately the same· elevation as the artificial depreSSion that is located at the northwestern tip of the property. The patch is just south of the depression. It is most likely located in an area that could not be developed due to steep slope ordinances. It is recommended that the area be preserved if at all possible when developing plans for the site. Sensitive Habitats Sensitive habitats are those that 1) are considered rare within the region, 2) support sensitive plant and/or wildlife species, or 3) function as corridors for wildlife movement. Coastal sage scrub and valley needlegrass grassland are both considered sensitive habitat types and impacts to them are regulated by the resource agencies. Regionally, coastal sage scrub provides habitat for numerous sensitive plant and wildlife species. Animals confined primarily to this habitat include California gnatcatcher, cactus wren, orange' throated whip tail, and San Diego horned lizard. Sensitive plants characteristic of coastal sage scrub include San Diego barrel cactus, ashy spike,moss, and California adolphia. This habitat type has been reduced by about 70% of its former coverage in the County as a result of agriculture, urbanization, and other development. Native grasslands (Le., valley needlegrass grassland) are considered sensitive because of their considerable reduction in acreage throughout the County. Grasslands may support several sensitive plant species, including San Diego thorn, mint, and San Diego golden~star. In addition, they provide foraging habitat for numerous species of sensitive rap tors. Page 4 '" 3.3 IMPAcT ANALYSIS Implementation of the proposed project would result in the direct loss of 0.61 acres of coastal sage scrub and no losses to sensitive plant species. The impact to the coastal sage scrub is a direct function of the requirement for fire suppression zones and only involves the thinning of underbrush. The table below illustrates the impacts to the existing plant communities onsite. The impact to the coastal sage scrub vegetation community will require mitigation. 0.79 o Non,Native Grass Land 0.88 o 0.88 Native Grass Land San :Mitigation Measures The BCS project includes in the project design the granting of an open space easement over 87 percent (4.25 acres) of the coastal sage scrub on the property. The onsite tmpact to coastal sage scrub is 0.61 acres. The onsite preservation is greater than the 2: 1 mitigation ratio that is typically required by the resource agencies for the impact of coastal sage scrub. With the preservation of 4.25 acres onsite, the impact to coastal sage scrub is fully mitigated. The open space easement also includes the preservation of 100 percent of native and non,native grasslands, chaparral and a rare population of San Diego thom,mint. Please feel free to contact me at (760) 942,5147 with questions or if you require additional information. Very truly yours, Anita M. Hayworth, Ph . Page 5 1~~~~:i'};~:~:::~ii::7;~~;~;~~1:~;;'~:; ""sJflbt·W(,S"'·"'·C"""" 'W·'·' , , "w,'W' ,'''" ",',--" .•.. ~,. ;:~l, ~i :~ ,k~~:;~ }~~~,~:~) :~~ J;!~i'_~P!~q~~I:i;[:0~~ ~)~r;~~~}/;~2;~'~jt:!J~~\;::~;~'~~~ Impacts to Existing Plant Communities Plant Community Existing Direct Open Space Acreage Impacts * Disturbed 10.50 5.69 4.81 Developed 0.33 0.3) 0 Coastal Sage Scrub 4.86 0.24 4.62 Chaparral 0.79 0 0.79 Non~Native Grassland 0.88 0 0.88 Native Grassland 0.61 0 0,61 San Diego Torn~Mint 0.03 0 0.03 Total 18.00 6.26 11.74 *Includes the entire limits of grading and all brush management zones ,~ .; : ............ , \\ .... '> •• \ ""'\ " -""', \\ '\ ... , " ~, ."",: . " , / "',. ,'. " '. \\ If ,; e ~ -------==::: ~~~ " . .• e ~ ~ 'M ... - '., e I VEGETAfTION TYPES: I BCSPrope~ Disturbed Habitat (DH) Coastal Sager Scrub (ess) Chaparral (SMC) Non-Native flrassland Native Gras~land(NGL) San Diego Thorn-Mint Totals ' CobblestonE }1roperty Disturbed IDibjtat (DB) Coastal Sage! Scrub (eSS) Chaparral (S~C) Non-Native ~~land Native Grassland (NGL) San Diego Thorn-Mint Totals Grading Impacts TotallImpaeted . 10.14 aclS.04 ac 4.86 aclO.61 ac . 0.79 aclO.O ac 0.88 ~O.Oac 0.61 aclO.O ac 0.03 aclO.O ac 17.31 adS.liS ae 4.46 acl3.64 ac 0.0 aclO.O ac 2.61 aclO.O ac 0.0 ac/O.O ac 0.0 aclO.O ac 0.0 aclO.O ac 7.07 aeJ3.64 ac -g Impacts from Fire Suppression Zones Impairts from Easements --- \ "\1(1 ~~J i I \ I ; ~-~--'--..::--= , \ \ Y....1lft) -r ~ '. " ~~~-~---::.. ... -~--_________ --.~---------------=-=--------------~--r--------=r--,~ ~ --.::=-:-----::::: ----.-'~ ------------_.----.--::: ------' -------'----------~ , --. ..-==------=--=-~--=--------------------".-----::=:::::::==:::::::::::--==-=-.......... --~ ~ -----"'- e +. / ~.:::.""., 1-~\\ ",--~I' , I' i~\ . ,. ~~ \ (~~/i ! j ~ ~'t / (", '2-ifZ2 L -... ",,--/ ~ "" / I "<, "..JQ1tl.+. ~ ''I VEGETATION ,TYPES: Habitat Type Disturbed Habitat (DH) Developed ,(DEV) Coastal Sage Scrub (CSS)* Chaparral (SMC) Non~Native Grassland Native Grassland (NGL) San ~Diego Thorn-Mint Total , Totalll m pact 10.50 ac/5.69~ac 0.33 ac/0.33 ac 4.86 ac/0.24 ac* 0.79 ac/O.O ac 0.88 ac/O.O ac '0.61 ac/O.O ac 0.03 ac/O.O ac 18.00 ac/6.26 ac * 0.16 ac is impacted for Fire Suppression ""', I.~l Grading Impacts ~ Impacts from Fire Suppression Zones