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BIOLOGICAL ASSESSMENT
FOR
CAMPOS VERDES
RANCHO CALIFORNIA, CALIFORNIA
Prepared for:
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Douglas Wood & Associates
1000 Quail Street, Suite 165
Newport Beach, CA. 92660
(714) 851-3119
Prepared by:
S. Gregory Nelson
Consulting Biologist
24230 Delta Drive
Diamond Bar, CA. 91765
November 3, 1989
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TABLE OF CONTENTS
PAGE
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I. INTRODUCTION 1
A. Purpose 1
B. Scope 1
II. METHODOLOGY 1
A. Literature Review 1
B. Field Investigation 2
III. EXISTING CONDITIONS 2
A. Biotic Communities 2
B. High Interest Species 4
C. Areas of Special Biological Importance 5
IV. PROJECT IMPACTS 5
A. Generic Impacts 5
B. Potentially Significant Adverse Impacts 7
C. Cumulative Impacts 7
V. MITIGATION MEASURES 7
VI. REFERENCES CITED g
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O I. INTRODUCTION
A. Purpose
The purpose of this report is to provide planners and
decision-makers with a biological assessment of proposed
development plans for the proposed Campos Verdes encompassing
approximately 131 acres located in western Riverside County near
Rancho California. Permanent development has been limited to
scattered ranch structures (now demolished), reservoirs (no longer
operational) and fences. Past and present land uses have been
limited to agriculture and grazing, however, localized areas of
naturalized grassland habitat remain on-site. In addition, one
endangered species is known to occur in the area of the project
site. The potential for the site to possess significant biological
resources, including the habitat of an endangered species warrant
this investigation and make its findings key to the environmental
review process.
B. Scope
The project site encompasses approximately 131 acres within
the general Rancho California area in Riverside County. The current
status, significance and sensitivity of biological resources on-
site are discussed and are then analyzed with respect to the direct
O and indirect potential impacts associated with the proposed
development plan. Based on the extent and magnitude of impacts
identified, mitigation measures are recommended.
Although a comprehensive background description of resources
within the entire site is provided, focus of the report is placed
on those resources of potential significance. For purposes of this
report, biological resources as used here refer to vegetation and
wildlife, including birds, mammals, reptiles and amphibians. No
attempt is made to address insects and other invertebrates. This
is an accepted professional practice, since invertebrate animals
are extremely difficult to inventory and vegetation and wildlife
serve as adequate indicators of biological impacts.
II. METHODOLOGY
A. Literature Review
The study began with a review of information sources relating
to biological resources of the project site and surrounding area.
Habitat designations used in this report are according to the basic
classification system of Munz and Keck (1959) as amplified by
Cheatham and Haller (1975) and Thorne (1976). Floral taxonomy
follows the current regional flora of Munz (1974). Common plant
names, where not available from Munz (1974}, are taken from Abrams
O (1923), Hitchcock (1950), and Robbins et al (1951). Vertebrates
identified in the field by sight, calls, tracks, scat or other
signs are cited herein according to the nomenclature of Stebbins
(1972) and Collins, et al. (1978) - amphibians and reptiles; Small
(1974) and AOU (1928) - birds; and Hall (1981) and Jones, et al. O
(1982) - mammals. Authorities used for determination of sensitive
biological resources are as follows: Plants - FWS (1982a), CDFG
(1982a), Smith, et al. (1980) and CNDDB (1983); Wildlife - FWS
(1982b), CDFG (1980, 1982b), and Tate and Tate (1982). Assisting
in the preparation of this report was documentation of regional
biological resources appearing in County of Riverside (MEI) and
local biological resources appearing in Pacific Southwest
Biological Services (1980) and The Planning Center (1988).
B. Field Investigation
The purpose of the field survey was two-fold. First, existing
information and preliminary mapping was verified and refined.
Second, site specific supplemental data was collected to give a
complete picture of biological resources on-site.
Site investigations were conducted on November 20, 1988 by
Mr. S. Gregory Nelson, Consulting Biologist. The entire property
was surveyed using an existing dirt access road and walk-over
surveys of those areas which are not accessible by vehicle. Weather
at the time of the survey was cool, with a temperature range of
approximately 50 degrees F to 60 degrees F. The physical nature of
the project site permitted a complete direct examination of
virtually all terrain within its confines. O
The survey did not employ quantitative census techniques.
Rather, emphasis was placed on the evaluation of habitat integrity
and importance, the inventory of plant and wildlife species, and
the delineation of significant habitat areas. Inventories were
conducted within several representative examples of the various
habitat types found on-site.
III. EXISTING CONDITIONS
A. Biotic Communities
Following are descriptions of the biotic communities -
consisting of plant and wildlife species found on-site. As the term
implies, biotic communities are predictable assemblages of species
which exist within the same physical habitat and have a very close
and complex set of interrelationships. Introduced grassland is the
only truly developed biotic community found on-site. For detailed
inventories of plant and wildlife species found on-site, the reader
is referred to a previous report prepared by The Planning Center
(1988), which is found as part of Appendix E, Biological
Assessments.
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O Introduced grassland covers the entire site. This community
derives its name from the predominance of introduced grass and herb
species which have replaced native vegetation as the result of
grazing and other past disturbances. It is a community which is
widespread in Southern California today, particularly the western
Riverside County area.
The introduced grassland on-site includes a variety of
"subcommunities", or, subtypes. The majority of the site is dryland
farmed. This was apparent from the predominance of barley (Hordeum
sp) which had been recently mowed and harvested. Generally, areas
being dryland farmed were those where the topography consisted of
gentle hillsides, ridgelines and narrow drainages. Such areas are
found over the northern half and along the southeastern portion of
the site.
In addition, there are areas in the central and southwestern
portion of the site which appear to have once been used as pasture.
In and around these areas, there are also several foundations from
raised buildings and abandoned ponds which do not appear to have
held water for some time. Only one of these impoundments has
riparian habitat associated with it in the form of several sapling
willows (Salix sp). This vegetation is very limited and poorly
developed, therefore, a riparian community is not considered to
exist.
O Common plant species found in all introduced grassland are
red-stemmed filaree (Erodium cicutarium), foxtail chess (Bromus
rubens), soft chess (Bromus mol is), wild oats (Avena fatua),
common barley (Hordeum vulaare), lupine (Luoinus sp and mustard
(Brassica aeniculata). Other species included croton (Croton
californicus), telegraph weed (Heterotheca grandiflora), cudweed
(Gnaothalium sp.), doveweed (Eremocarous setiaerus), and western
ragweed (Ambrosia osilostachva). In physical appearance, this
vegetation forms a dense groundcover, growing to a height of
approximately two to four feet (except when mowed or grazed). As
a result of its annual lifeform, introduced grassland typically
sprouts and grows rapidly following the onset of the winter rains
with the most flowering taking place in the spring. Plants then
die back and dry out over the summer and fall.
Due to their altered conditions, large, open expanses of
introduced grasslandand and dryland farmed areas generally support
a limited abundance and diversity of wildlife and dryland farmed
area. Several ground-nesting birds and burrowing mammals were
observed, including the western meadowlark, mourning dove, beechy
ground squirrel, audubon cottontail, and valley pocket gopher.
Other species typical of grassland foraging habitat were observed
as well. These included the red-tailed hawk, American kestrel,
turkey vulture, brewers blackbird, and loggerhead shrike. A number
O of other species are expected including western fence lizard, side-
blotched lizard, gopher snake, horned lark, vesper sparrow,
killdeer; deer mouse, and coyote.
C. High Interest Species
The site is located within the geographical range of one
species designated as "endangered" by the U.S Fish and Wildlife
Service. This is the Stephen's kangaroo rat, (Dioodomys stephensi).
Historically, the species was found throughout the San Jacinto
Valley of Riverside County, with small populations also being found
in southern San Bernardino Valley and north-western San Diego
County. Recent research, however, indicates the current
distribution of this species includes many disjunct isolated
localities. This reduction is believed to be due to widespread
agricultural and urban development within areas of preferred
habitat. Based on information gathered to date, soil types and
vegetation density appear to be the primary ecological factors
limiting the distribution of this species (Bleich, 1977, 1973;
Thomas, 1975). Generally, populations are found in soils having
high percentages of sand and gravel in relatively flat or gently
rolling areas and covered by open, grassy herblands where scattered
shrubs occur.
Based on field observations, the site is not believed to
contain any habitat areas suitable for the Stephen's kangaroo rat.
As described above, essentially the entire site is under dryland
farming, which involves annual mowing and tilling. In addition a
Stephen's kangaroo rat survey and trapping program was conducted
over an approximately 120 acre portion of the project site (The
Planning Center, 1988), including habitat areas similar to those
found over the entire site. This survey and trapping program
resulted in no Stephen's kangaroo rat captures, observed tracks,
or other evidence indicating their presence. However, it is
anticipated that the presence or absense of the SKR will be
determined separately from this report.
The project site is also within the geographical range of the
San Diego horned lizard and the orange-throated whiptail, both of
which are listed as "Species of Special Concern" by California
Department of Fish and Game. Although worth mentioning, these
species are not expected to occur on-site due to its disturbed
condition. The site also provides potential habitat for a group
of birds included on the Audubon Society's early warning list,
known as the'"Blue List" (Tate et. al. 1982). These bird species
are listed below:
Marsh hawk
Turkey vulture
Snowy plover
Merlin
American kestrel
Ferruginous hawk
Loggerhead shrike
Vesper sparrow
Prairie falcon
Burrowing owl
Barn owl
Short-eared owl
Bewick's wren
Western bluebird
Grasshopper sparrow
Savannah sparrow
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O Blue-listed species are not rare or endangered and the listing
is advisory only. According to the Audubon Society, the list is an
early warning list of species whose populations indicate non-
cyclical declines or range contractions and which are recommended
for monitoring by wildlife agencies, conservation groups and
individual researchers.
No rare or endangered plant species are reported or expected
from the project area (Smith et.al. 1980).
D. Areas of Special Biological Importance
As indicated by the preceding discussion, the site provides
habitat for a number of wildlife species. However, none of these
species are rare or endangered. The area is considered to be a
fairly important raptor wintering area. This determination was made
as a result of the area being a location where raptorial birds
(hawks, vultures, eagles, owls and falcons) concentrate due to a
high abundance-of roosting sites, a good supply of prey species
(small mammals and birds) and suitable hunting habitat (generally
open brushland and grassland). As a raptor wintering area, however,
the site is not of high significance within the context of regional
biological resources. It was not, for example, called out as an
area of high biological importance by the California Department of
Fish and Game (1979) as was the area around Perris Reservoir
O because of its raptor habitat.
IV. PROJECT IMPACTS
A. Generic Impacts
1. Causal Factors
Adverse impacts to vegetation and wildlife are expected to
occur as the result of several causal factors originating with the
construction, presence and inhabitation of urban development as
proposed. These causal factors can be grouped into two major
categories -- the removal or alteration of physical habitats
through earthwork and the introduction of increased ambient noise
levels, exogenous species and other disturbances related to man's
activities.
Biotic communities, as described in the previous section are
assemblages of plant and animal species occurring in the same
physical habitat. They occur together in an orderly predictable
manner and have a very close and complex set of interrelationships.
As a consequence, first order impacts resulting from causal factors
will, in turn, result in second order impacts which will, in turn,
result in third order impacts, and so on. Typically, the degree to
which this chain-like reaction proceeds toward the complete
O breakdown and loss of community stability and integrity will depend
on the severity and magnitude of the causal factor.
2. Loss of Habitat O
Construction activities will result in the removal of physical
habitats through cut, fill and other grading activities necessary
for roads, building pads, utilities, fuel modification and flood
control. The first order impacts of habitat loss will be the direct
loss of vegetation and the destruction of less mobile wildlife
forms.
In and of itself, the significance of vegetation loss will
depend on the diversity and availability of plant communities and
associations affected. From the standpoint of biological diversity,
the loss of introduced grassland from the site will not constitute
a significant adverse impact. The same will be true for the loss
of less mobile wildlife forms since they are highly habitat
dependent and their abundance and diversity are directly related
to those of their habitats.
The impacts of vegetation loss through direct removal will,
in turn, have potential effects on wildlife. As vegetation is
removed or otherwise destroyed, the associated wildlife will either
be destroyed (as mentioned above for less mobile forms) or will be
displaced to adjacent habitat areas where they will crowd and
disrupt local populations. Although increased competition and
predation will act rapidly to return population numbers to habitat
carrying capacity levels, either displaced or local wildlife will O
be lost. Since the determinants of their severity are the relative
importance of habitats lost to local and regional wildlife
populations, the abundance and diversity of wildlife these habitats
support, the availability of these habitats, and the habitat
dependency of the associated wildlife, the loss of habitat from the
site will not be significant.
3. Harassment of Wildlife
Causal factors generated during human activities resulting
from the construction and inhabitation of urban land uses may be
collectively termed "harassment".
Harassment is defined as those activities of man and his
associated domestic animals which increase the physiological costs
of survival or decrease the probability of successful reproduction
in wildlife populations. The most common form of harassment
expected to accompany development of the site include excessive
construction-related noise, background noise, light and glare and
the introduction of feral cats, dogs and children which are
unnatural predators and competitors for wildlife.
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O B. Potentially Significant Adverse Impacts
Conversion of the on-site introduced grassland biotic
community to urban development will reduce areawide dryland farming
foraging habitat for raptors. As previously mentioned, however,
the area is not considered to be of high significance in this
regard, nor does it contain the habitat for rare and endangered
species and the loss of habitat will not be significantly adverse.
The same holds true for the loss of habitat supporting other
grassland species of wildlife.
Based upon these findings, it is concluded that the proposed
project will not result in significant adverse impacts.
C. Cumulative Impacts
Although not significant in itself, the loss of introduced
grassland habitat described above for the proposed project will
contribute on an incremental basis to cumulative impacts to
biological resources on a regional basis. These impacts are those
which are now occurring in the region as a result of past and
planned developments in the region. These impacts include:
-An overall reduction in the naturalized biotic resources of
the region.
-Loss of secondary foraging habitat for migratory
populations of birds of prey which are winter visitors to t h e
region.
V. MITIGATION MEASURES
The proposed project will not result in any significant
adverse impacts. Therefore, no mitigation measures for biological
impacts are warranted, and none are recommended.
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VI. REFERENCES CITED O
Abrams, Leroy. 1923. "Illustrated Flora of the Pacific States.
Stanford University Press, Stanford, CA. 4 Volumes.
American Ornithologist's Union (AOU). 1957. Thirty-fourth
Supplement to the AOU Checklist of North American Birds. Auk
(Suppl.) 99(3): lcc-16cc.
Beauchamp, R.M. 1980. Report of a Biological Survey of the
Interstae 15 - Rancho Villages Portions of Rancho California,
Riverside County.
Bleich, V.C. and O.A. Schwartz. 1974. Western Range Extension of
Stephans Kangaroo Rat ("Dipodomys Stephensi"). A Threatened
Species. California Fish and Game 60: 208-210
California Department of Fish and Game. 1979. Areas of Special
Biological Importance. State of California Resources Agency,
Sacramento, CA.
California Department of Fish and Game (CDFG). 1980. "At the
Crossroads: A report on the Status of California's Endangered and
Rare Fish and Wildlife". State of California Resources Agency,
Sacramento, CA. 147 pp. + Addenda.
California Department of Fish and Game (CDFG). 1982a. "Designated
Endangered or Rare Plants". Summary list from Section 1904 Fish
and Game Code (Native Plant Protection Act). State of California
Resources Agency, Sacramento, CA. Opp.
California Department of Fish and Game (CDFG) 1982b. "Endangered,
Rare and Threatened Animals of California", Revised March 15, 1982.
State of California Resources Agency, Sacramento, CA. Photocopied
List. Opp.
California Natural Diversity Data Base (CNDDB). 1983. Data Base
Record Search for Information on Threatened, Endangered, Rare or
Otherwise Sensitive Species and Communities in the Vicinity of
Desert Hot Springs, Riverside County, California. California
Department of Fish and Game, State of California Resources Agency,
Sacramento, California.
Cheatham, Norden H. and J. Robert Haller, 1976. "An Annotated List
of California Vegetation Types". Berkeley, CA: University of
California Natural Lands and Water Reserve System.
Collins, J.T., J.E., Hukeey, J.L. Knight and H.M. Smith. 1978.
"Standard Common and Current Scientific Names for North American
Amphibians and Reptiles". Soc. Study Amphibians and Reptiles. Herp.
Circ. 7. O
County of Riverside. 1981. General Plan, Environmental Management
Element. County Planning Dept., Riverside, CA.
Fish and Wildlife Service (FWS). 1982a and 1982b. "Endangered and
Threatened Plants and Wildlife", In: "Endangered and Threatened
Wildlife and Plants". Federal Register 50 CFR 17.11 Aand 17.12.
U.S. Department of the Interior, Reprint. 13pp.
Hall, E.R. 1981. "The Mammals of North America". John Wiley & Sons,
New York, NY.
Hitchcock, A.S. 1950. "Manual of the Grasses of the United States".
U.S. Department of the Agriculture Miscellaneous Publication No.
200. U.S. Government Printing Office, Washington D.C. 1051 pp.
Jones, Jr., J.K., D.C. Carter, H.H. Genoways, R.S. Hoffman and D.W.
Rice. 1982. "Revised Checklist of North American Mammals North of
Mexico, 1982". "OCCdS. Pap. Mus. Texas Tech Univ.", No. 80.
Munz, Phillip A. 1974. "A Flora of Southern California". University
of California Press, Berkeley, CA. 1086 pp.
Munz, Phillip A. and David D. Keck. 1959. "A California Flora".
University of California Press, Berkeley, CA. 1681 pp.
Pacific Southwest Biological Services. 1980. Rancho Villages Policy
Plan General Plan Amendment. County of Riverside.
O Robbins, W.W., Margaret K. Bellue and Walter S. Ball. 1951. "Weeds
of California". State of California Department of Agriculture. 547
PP•
Small, Arnold. 1974. "The Birds of California". MacMillan
Publishing Co., New York NY. 270 pp.
Smith, James P. Jr., R. Jane Cole and John O. Sawyer, Jr. 1980.
"Inventory of Rare and Endangered Vascular Plants of California".
Special Publ. No.l (2nd Edition), California Native Plant Society.
115 pp. + Supplements.
Stebbins, R. C. 1972. "Amphibians and Reptiles of California".
University of California Press, Berkeley, CA.
Tate, James, Jr. and D. Jean Tate. 1982. "The Blue List for 1982".
American Birds 36(2): 126-135.
The Planning Center. 1988. Biological Survey for Rancho California
Parcel BP7-1, Parcel Map No. 23336. Prepared for Rancho California
Development Company.
Thomas, J.R. 1973. Stephen's Kangaroo rat Survey, 1972-1973.
California Department of Fish and Game Wildlife Admin. Rep. 73-5.
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Thomas, J.R. 1975. "Distribution, Population Densities and Home O
Range Requirements of the Stephen's Kangaroo Rat (Dipodomys
stepehnsi). M.A. Thesis, California State Polytechnic University,
Pomona. vii + 64 pp.
Thorne, Robert F. 1976. "The Vascular Plant Communities of
California". in Lattinq, June ed. "Plant Communities of Southern
California". Riverside, CA: California Native Plant Society Special
Publication No. 2, pp. 1-31.
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