[Federal Register Volume 74, Number 165 (Thursday, August 27, 2009)]
[Proposed Rules]
[Pages 44238-44267]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-20499]



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Part III





Department of the Interior





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Fish and Wildlife Service



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50 CFR Part 17



Endangered and Threatened Wildlife and Plants; Designation of Critical 
Habitat for Ambrosia pumila (San Diego ambrosia); Proposed Rule

Federal Register / Vol. 74, No. 165 / Thursday, August 27, 2009 / 
Proposed Rules

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

[Docket No. FWS-R8-ES-2009-0054; 92210-1117-0000-B4]

50 CFR Part 17

RIN 1018-AW20


Endangered and Threatened Wildlife and Plants; Designation of 
Critical Habitat for Ambrosia pumila (San Diego ambrosia)

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to 
designate critical habitat for Ambrosia pumila (San Diego ambrosia) 
under the Endangered Species Act of 1973, as amended (Act). In total, 
approximately 802 acres (ac) (324 hectares (ha)) of land are being 
proposed for designation as critical habitat. The proposed critical 
habitat is located in Riverside and San Diego Counties, California.

DATES: We will consider comments we receive on or before October 26, 
2009. We must receive requests for public hearings, in writing, at the 
address shown in the FOR FURTHER INFORMATION CONTACT section by October 
13, 2009.

ADDRESSES: You may submit comments by one of the following methods:
    <bullet<ls-thn-eq> Federal eRulemaking Portal: http://www.regulations.gov. Follow the instructions for submitting comments to 
Docket No. FWS-R8-ES-2009-0054.
    <bullet> U.S. mail or hand-delivery: Public Comments Processing, 
Attn: FWS-R8-ES-2009-0054; Division of Policy and Directives 
Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive, 
Suite 222; Arlington, VA 22203.
    We will post all comments on http://www.regulations.gov. This 
generally means that we will post any personal information you provide 
us (see the Public Comments section below for more information).

FOR FURTHER INFORMATION CONTACT: Jim Bartel, Field Supervisor, U.S. 
Fish and Wildlife Service, Carlsbad Fish and Wildlife Office, 6010 
Hidden Valley Road, Suite 101, Carlsbad, CA 92011; telephone (760) 431-
9440; facsimile (760) 431-5901. If you use a telecommunications device 
for the deaf (TDD), call the Federal Information Relay Service (FIRS) 
at (800) 877-8339.

SUPPLEMENTARY INFORMATION:

Public Comments

    We intend that any final action resulting from this proposed rule 
will be based on the best scientific and commercial data available and 
be as accurate and as effective as possible. Therefore, we request 
comments or information from the public, other concerned government 
agencies, the scientific community, industry, or other interested party 
concerning this proposed rule. We particularly seek comments 
concerning:
    (1) The reasons why we should or should not designate habitat as 
``critical habitat'' under section 4 of the Endangered Species of 1973, 
as amended (Act) (16 U.S.C. 1531 et seq.), including whether there are 
threats to the species from human activity, the degree of which can be 
expected to increase due to the designation, and whether that increase 
in threat outweighs the benefit of designation such that the 
designation is not prudent.
    (2) Specific information that may assist us in clarifying or 
identifying more specific primary constituent elements (PCEs). There is 
a lack of specific information available regarding what constitutes 
physical and biological features essential to the conservation of this 
species. Additionally, the available information does not identify a 
consistent pattern in specific life-history requirements and habitat 
types where Ambrosia pumila is found. For these reasons, the PCEs in 
this proposed rule are broad and based on our assessment of the 
ecosystem settings in which the species has most frequently been 
detected and our best assessment regarding its life history requisites. 
We specifically seek information that may assist us in defining those 
physical and biological features essential to the conservation of the 
species which may require special management considerations or 
protection, or in identifying specific areas outside the geographical 
area occupied by the species at the time it was listed that may be 
essential to the conservation of the species. In particular, answers to 
the following questions may be helpful to clarify or identify more 
specific PCEs of Ambrosia pumila habitat:
    <bullet> Does the species reproduce via seed? If so, does the 
species rely on some aspect of its environment to trigger seed 
germination?
    <bullet> What are the key factors determining why the species 
occupies the particular areas it occupies (but not other areas with the 
same habitat type)? For example, what role does proximity to waterways 
or vernal pools play?
    (3) The appropriateness of designating critical habitat for this 
species. If the broad essential physical and biological features 
proposed for Ambrosia pumila habitat cannot be defined more 
specifically, or we cannot reasonably identify essential habitat for 
this species based on our evaluation of information received, it may be 
difficult to identify specific areas as critical habitat for this 
species. This may be the case if specific information regarding what 
constitutes essential habitat for this species cannot be obtained, or 
if the data obtained suggest that the species can effectively carry out 
all necessary life functions in a range of habitat types and conditions 
(i.e., there may not be specific habitat features essential to the 
conservation of the species).
    (4) Specific information on:
    <bullet> The amount and distribution of Ambrosia pumila habitat 
included in this proposed rule,
    <bullet> What areas occupied at the time of listing that contain 
features essential for the conservation of the species should we 
include or exclude in the designation and why, and
    <bullet> What areas not occupied at the time of listing are 
essential to the conservation of the species and why.
    (5) How the proposed critical habitat boundaries could be refined 
to more closely circumscribe the areas identified as essential. We also 
seek recommendations to improve the methodology used to delineate the 
areas proposed as critical habitat; especially comments regarding how 
we might more accurately estimate the additional surface area beyond 
the visible surface area covered by the aerial stems that we need to 
include for each occurrence of Ambrosia pumila in the critical habitat 
designation to ensure that habitat areas do not exclude unseen 
underground portions of A. pumila plants (see step number 4 in the 
Methods section below).
    (6) Land use designations and current or planned activities in the 
areas proposed as critical habitat and their possible impacts on the 
species and the proposed critical habitat.
    (7) Any probable economic, national security, or other relevant 
impacts of designating any area that may be included in the final 
designation. We are particularly interested in any impacts on small 
entities, and the benefits of including or excluding areas that exhibit 
these impacts.
    (8) Any issues with the exclusions being considered under section 
4(b)(2) of the Act as part of this proposed designation, or reasons why 
any proposed critical habitat not considered for exclusions should be 
excluded.
    (9) Any special management considerations or protections that the 
proposed critical habitat may require.
    (10) Whether we could improve or modify our approach to designating

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critical habitat in any way to provide for greater public participation 
and understanding, or to better accommodate public concerns and 
comments.
    (11) Whether the benefit of an exclusion of any particular area 
outweighs the benefit of inclusion under section 4(b)(2) of the Act, in 
particular for those areas covered by the Western Riverside County 
Multiple Species Habitat Conservation Plan (Western Riverside MSHCP), 
and Subarea Plans (City of San Diego and County of San Diego) under the 
San Diego Multiple Species Conservation Program (MSCP), and specific 
reasons why.
    (12) Whether the benefit of excluding the area proposed as critical 
habitat within the City of Oceanside in San Diego County (Subunit 4C) 
under section 4(b)(2) of the Act outweighs the benefit of including 
this area as critical habitat, and specific reasons why. The City of 
Oceanside is working on a Subarea Plan under the Northwestern San Diego 
County Multiple Habitat Conservation Plan (MHCP) in cooperation with 
the Service.
    Our final determination concerning critical habitat for Ambrosia 
pumila will take into consideration all written comments and comments 
received during a public hearing, should one be requested, and any 
additional information we receive during the public comment period. 
These comments will be included in the public record for this 
rulemaking. Our final determination will also incorporate all comments 
requested of peer reviewers and received during the comment period. 
Finally, our final determination concerning critical habitat will 
consider all written comments and any additional information we receive 
during the comment period for the draft Economic Analysis (DEA). On the 
basis of peer reviewer and public comments, we may, during the 
development of our final determination, find that areas within those 
proposed do not meet the definition of critical habitat, that some 
modifications to the described boundaries are appropriate, or that 
areas are not appropriate for exclusion under section 4(b)(2) of the 
Act.
    You may submit your comments and materials concerning this proposed 
rule by one of the methods listed in the ADDRESSES section.
    We will post your entire comment--including your personal 
identifying information--on http://www.regulations.gov. If you provide 
personal identifying information in addition to the required items 
specified in the previous paragraph, such as your street address, phone 
number, or e-mail address, you may request at the top of your document 
that we withhold this information from public review. However, we 
cannot guarantee that we will be able to do so.
    Comments and materials we receive, as well as supporting 
documentation we used in preparing this proposed rule, will be 
available for public inspection at http://www.regulations.gov, or by 
appointment, during normal business hours, at the U.S. Fish and 
Wildlife Service, Carlsbad Fish and Wildlife Office (see FOR FURTHER 
INFORMATION CONTACT).
    You may obtain copies of the proposed rule by mail from the 
Carlsbad Fish and Wildlife Office (see FOR FURTHER INFORMATION CONTACT) 
or by visiting the Federal eRulemaking Portal at http://www.regulations.gov.

Background

    It is our intent to discuss only those topics directly relevant to 
the designation of critical habitat in this proposed rule. This rule 
incorporates new information on the biology, distribution, and 
abundance of Ambrosia pumila that we did not discuss in the 2002 final 
listing rule for this species (67 FR 44372). For more information on A. 
pumila, refer to that final listing rule, which was published in the 
Federal Register on July 2, 2002.

Previous Federal Actions

    Ambrosia pumila was listed as an endangered species on July 2, 2002 
(67 FR 44372). Designation of critical habitat was found to be prudent 
in the proposed (64 FR 72993; December 29, 1999) and final listing 
rules, but was deferred due to budgetary constraints and higher listing 
priorities. The Center for Biological Diversity filed a complaint in 
the U.S. District Court for the Southern District of California on 
December 19, 2007, challenging failure of the Service to designate 
critical habitat for four endangered plants, including A. pumila 
(Center for Biological Diversity v. United States Fish and Wildlife, et 
al., Case No. 07-CV-2378 NLS). The April 11, 2008, settlement agreement 
stipulates that the Service shall submit a determination as to whether 
it is prudent to designate critical habitat for A. pumila, and if 
prudent, a proposed critical habitat designation to the Federal 
Register for publication on or before August 20, 2009, and submit a 
final critical habitat designation to the Federal Register for 
publication on or before August 19, 2010. In this proposed critical 
habitat rule, we reaffirm that determination of critical habitat for A. 
pumila is prudent. However, we may revisit our prudency determination 
following additional review and consideration of information we receive 
during the public comment period.

Species Description

    Ambrosia is a genus comprising 35 to 50 wind-pollinated annual and 
perennial plant species in the Asteraceae (sunflower) family. Members 
of this genus occur predominantly in the Western Hemisphere, especially 
North America. Species are generally found in arid or semiarid areas, 
while some are weeds of cultivated fields or strand species of Pacific 
and Caribbean beaches (Payne 1976, p. 169).
    Ambrosia pumila is a clonal herbaceous perennial. Individual stems 
are generally 5 to 30 centimeters (cm) (2 to 12 inches (in)) tall, but 
may grow to 50 cm (20 in), and are densely covered with short hairs. 
The leaves are two to four times pinnately divided into many small 
segments and are covered with short, soft, gray-white, appressed (lying 
flat on surface) hairs. The species has separate male and female 
flowers on the same plant (monoecious). The male flowers have no 
petals, are yellow to translucent, and are borne in clusters on 
terminal flower stalks. The female flowers have no petals and are 
yellowish-white. Female flowers are in clusters in the axils of the 
leaves below the male flower clusters (Nuttall 1840, pp. 344-345; Gray 
1882, p. 217; Munz 1935, p. 544; Keck 1959, p. 1103; Ferris 1960, p. 
148; Munz 1974, p. 112; Beauchamp 1986, p. 94; Payne 1993, p. 194). 
Female flowers produce a dry, single-seeded fruit called an achene. 
References to seeds in this document refer to the single-seeded fruits.
    Ambrosia pumila spreads vegetatively by means of slender, branched, 
underground root-like rhizomes from which new aboveground stems (aerial 
stems or ramets) arise each year (Nuttall 1840, p. 344; Munz 1974, p. 
112; Payne 1993, p. 194). This growth pattern results in numerous 
aerial stems interconnected by a system of rhizomes, called a clone. 
All aerial stems growing from the same root system are genetically 
identical and represent a single individual A. pumila plant (called a 
genet) (Harper 1977, p. 26). Growing rhizomes extend underground beyond 
the aboveground limit of the aerial stems into adjacent suitable 
habitat, allowing rhizomes of adjacent individuals to intermingle. The 
underground interconnections can break or disintegrate, resulting in 
aerial stems that are genetically identical but physically separate 
(McGlaughlin and Friar 2007, p. 319). The extent to which

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rhizomes are capable of spreading has been observed only in individuals 
translocated to previously unoccupied sites. For example, A. pumila 
individuals transplanted on the San Diego National Wildlife Refuge in 
January 2008 were documented to produce new stems several inches away 
within 10 months (by November 2008). Additionally, A. pumila 
individuals transplanted in 1997 to an unoccupied site at Pilgrim Creek 
just south of Marine Corps Base Camp Pendleton in San Diego County were 
documented to produce new stems up to 70 in (178 cm) from the original 
stems within 2 years (by 1999) (Johnson et al. 1999, p. 3).
    Because of the clonal nature of Ambrosia pumila's growth, it is not 
possible to directly determine the number of genetically distinct 
plants present in an area simply by counting stems (McGlaughlin and 
Friar 2007, p. 320). McGlaughlin and Friar's (2007, p. 323) analysis of 
clonality in A. pumila determined that the aerial stem-to-genet ratio 
is roughly 10-to-1 on average (about 1 genet for every 10 aerial stems 
counted in a patch (cluster of stems)). A patch constitutes a spatially 
distinct cluster of stems within an occurrence, whereas an occurrence 
constitutes a group of individuals separated from the next nearest 
group of individuals by a distance greater than or equal to 0.25 mile 
(mi) (0.40 kilometer (km)).

Habitat

    Ambrosia pumila occurs primarily on upper terraces of rivers and 
drainages (Beauchamp 1986, p. 94; Johnson et al. 1999, p. 1; 
McGlaughlin and Friar 2007, p. 321; California Natural Diversity 
Database data report for A. pumila 2008 (CNDDB 2008)); however, several 
patches of the plant occur within the watershed of a large vernal 
(ephemeral) pool in the Skunk Hollow preserve in Riverside County 
(Dudek 2003, p. P-326; CNDDB 2008). Within these areas, the species is 
found in open grassland of native and nonnative plant species, and 
openings in coastal sage scrub (Johnson et al. 1999, p. 1; Dudek 2000, 
p. 18; Dudek 2003, p. P-330; CNDDB 2008), and primarily on sandy loam 
or clay soils (Johnson et al. 1999, p. 1; Dudek 2000, p. 18; CNDDB 
2008; USDA 2008). The species may also be found in ruderal habitat 
types (disturbed communities containing a mixture of native and 
nonnative grasses and forbs) such as fire fuel breaks and edges of dirt 
roadways (Beauchamp 1986, p. 94; Payne 1993, p. 194; CNDDB 2008). 
Nonnative grassland and ruderal habitat types provide adequate habitat 
for A. pumila; however, nonnative plants can out-compete A. pumila 
plants for resources in some situations if not managed. Occurrences are 
disjunct (generally 1 or more miles (1.6 or more km) apart) and most 
locations have been subjected to disturbance such as nonnative plant 
invasion, mining activities, development, grading, and human 
encroachment on foot, horses, or vehicles (CNDDB 2008).
    It is unclear why Ambrosia pumila consistently occurs in areas near 
waterways such as upper terraces of rivers or other water bodies. The 
areas where the species is found do not necessarily provide high levels 
of soil moisture, and A. pumila is adapted to dry conditions (Keck 
1959, p. 1103; Munz 1974, p. 112; Dudek 2000, Appendix A; CNLM 2008, p. 
18). Additionally, Service biologists have observed green (that is, not 
desiccated) aerial stem shoots of A. pumila after small amounts of 
precipitation and after other vegetation in the observed area had 
desiccated. Ambrosia pumila may require periodic flooding for dispersal 
of seeds and roots dislodged during flooding, seed germination, or some 
other segment of its life cycle. Further, areas subject to periodic 
flooding appear to be less amenable to competing nonnative and native 
plants.

Life History

    The reproductive biology of Ambrosia pumila has not been studied to 
the same extent as the more common Ambrosia species, such as A. 
artemisiifolia (common ragweed) and A. trifida (giant ragweed) (Dudek 
2000, p. 16). Thus, little is known about its pollination system, seed 
production, seed dispersal, and germination (Dudek 2000, p. 16; Dudek 
2003, p. P-331; McGlaughlin and Friars 2007, p. 320).
    Aerial stems of Ambrosia pumila sprout from their underground 
rhizomes in early spring after winter rains, and flower between May and 
October (Keck 1959, p. 1103). Recently, however, Service biologists 
observed aerial stems sprouting under dry conditions in late fall 
(Folarin 2008, pers. comm.). The plants senesce after the growing 
season, leaving the root system in place from which new aerial stems 
may sprout when environmental conditions are appropriate (Keck 1959, p. 
1103).
    Ambrosia pumila is presumed to be wind-pollinated because most 
other species of Ambrosia are wind-pollinated, and because biological 
pollinators have not been observed visiting A. pumila flowers (Johnson 
et al. 1999, p. 4; Dudek 2000, p. 16; Dudek 2003, p. P-331). 
Alternatively, pollinator(s) of A. pumila may have been extirpated 
(Dudek 2003, p. P-331). The species is presumed to be capable of self-
pollination and of being self-fertile (i.e., self-compatible, where 
pollen from an individual plant can fertilize an ovule on the same 
plant, resulting in production of viable seed) because other species of 
Ambrosia are capable of self-pollination (Payne 1976, pp. 171-172). The 
configuration of the male flowers in relation to the female flowers 
also implies opportunity for self-pollination (Dudek 2000, p. 16). 
However, studies are needed to determine whether viable seed is 
produced through self-pollination in this species (Johnson et al. 1999, 
p. 4; Dudek 2000, p. 16; Dudek 2003, p. P-332; McGlaughlin and Friars 
2007, p. 329).
    Ambrosia pumila is thought to have limited sexual reproductive 
output due to low production of viable seed (Johnson et al. 1999, pp. 
1-5; Dudek 2000, pp. 16-17; Dudek 2003, pp. P-331-P-332). Low seed 
production in this species is inferred by the lack of fertile fruits on 
all but a few preserved A. pumila museum specimens (Wallace 1999, pers. 
comm.), and field observers have found seed production in A. pumila to 
be low (Dudek 2000, p. 17; Dudek 2003, p. P-332). Specific germination 
requirements of A. pumila seed are unknown. A 1998 germination study 
using 22 A. pumila seeds of unknown viability collected from 3 sites at 
Mission Trails Regional Park did not result in any germination of 
seedlings (Dudek 2000, Appendix B). The lack of germination could have 
been due to the seeds being nonviable or to inappropriate germination 
conditions. Regardless of what proportion of A. pumila seeds are 
viable, low seed production implies that little sexual reproduction is 
occurring in this species. Low levels of sexual reproduction is not an 
unusual condition in clonal plant species (Sackville et al. 1987, p. 
54). This reduced sexual reproduction may negatively impact the ability 
of the species to adapt to rapid environmental change or environmental 
change over the long term, which is especially deleterious to a rare 
species with disjunct occurrences such as A. pumila (Dudek 2000, p. 17; 
Dudek 2003, p. P-332).
    The dispersal strategy of Ambrosia pumila is unknown. Ambrosia 
pumila seeds lack structures that facilitate dispersal by wind or 
passing animals (Nuttall 1840, p. 344; Payne 1993, p. 194). The species 
may depend on periodic flooding of nearby waterways for dispersal of 
seeds and rhizomes that can produce new aerial stems (Dudek 2003, p. P-
332). The longevity of individual plants is also unknown,

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although plants with clonal growth patterns tend to be long-lived 
(Watkinson and White 1985, pp. 44-45; Tanner 2001, p. 1980). Finally, 
the longevity of seeds and potential for buried seed banks to develop 
in the soil is unknown.

Genetics

    Little is known about genetic diversity or genetic distribution of 
Ambrosia pumila across its range. McGlaughlin and Friar (2007) 
conducted a genetic study of A. pumila to address conservation and 
management of the species. They found that each population they 
examined contained multiple genetically distinct individuals, but no 
individuals that occurred in more than one population. Therefore, they 
concluded that in order to maintain a level of genetic diversity 
capable of responding to variable ecological conditions, conservation 
of the species should involve the protection and maintenance of as many 
populations of A. pumila as possible (McGlaughlin and Friar 2007, pp. 
319 and 329).

Geographic Range and Status

    Ambrosia pumila is distributed in southern California from 
northwestern Riverside County, south through western San Diego County, 
to northwestern Baja California, Mexico (CNDDB 2008). It is generally 
found at or below elevations of 1600 feet (ft) (487 meters (m)) in 
Riverside County, and 600 ft (183 m) in San Diego County (CNDDB 2008). 
When listed as endangered under the Act in 2002, 15 occurrences of A. 
pumila were known in the United States: 3 in Riverside County and 12 in 
San Diego County (67 FR 44372; July 2, 2002). As noted previously, the 
term ``occurrence'' as used in this proposed critical habitat rule is 
defined as one or more A. pumila plants more than 0.25 mi (0.40 km) 
from another individual or group of individuals (Bittman 2002, in 
litt.). More than 80 percent of the occupied sites identified in the 
final listing rule were concentrated in the following 6 areas:
    <bullet> Near Alberhill about 2.1 mi (3.5 km) to the northwest of 
the Nichols Road site in Riverside County;
    <bullet> Along Nichols Road in the City of Lake Elsinore, Riverside 
County;
    <bullet> Near the Skunk Hollow vernal pool in southwestern 
Riverside County;
    <bullet> Adjacent to State Route 76 in northern San Diego County;
    <bullet> Mission Trails Regional Park, in the City of San Diego, 
San Diego County; and
    <bullet> San Diego National Wildlife Refuge near the unincorporated 
community of Jamul in southern San Diego County.
    According to information used to develop the final listing rule (67 
FR 44372; July 2, 2002), roughly 44 ac (18 ha)) of habitat in San Diego 
County was occupied by this species in 12 occurrences. This habitat 
estimate only includes areas where A. pumila stems were found in the 5 
to 10 years prior to listing in 2002. Similar area estimate data were 
unavailable for the 3 occurrences in Riverside County.
    Since this species was listed, one occurrence was identified in 
Riverside County about 1 mile (1.6 km) south of Skunk Hollow along San 
Diego aqueduct, from a survey report (AMEC 2006, pp. 12-13; CNDDB 
2008), and one occurrence was identified in unincorporated San Diego 
County on the west side of State Route 76, south of Olive Hill Road 
(see ``Criteria Used to Identify Critical Habitat'' below). Also since 
listing, we determined that one occurrence, on the west side of 
Interstate 15 just north of Lake Hodges and south of Via Rancho Parkway 
in San Diego County, previously identified as extirpated or not viable 
in the final listing rule is now extant and viable.
    The documented range of Ambrosia pumila in Mexico at the time of 
listing extended from Cabo Colonet south to Lake Chapala in north-
central Baja California, Mexico (Burrascano and Hogan 1996, p. 8). Two 
of these three occurrences were confirmed by David Hogan, formerly with 
the Southwest Center for Biological Diversity (now Center for 
Biological Diversity), and Cindy Burrascano of the California Native 
Plant Society (CNPS), San Diego Chapter (Burrascano and Hogan 1996, p. 
8). Although additional occurrences may have existed in Baja 
California, the species was not considered to be widespread at the time 
of listing due to the lack of appropriate habitat and impacts from 
agriculture and urban development, especially near the coast 
(Burrascano and Hogan1996, p. 8).
    All currently known occurrences are believed to have been present 
at the time of listing because plants with clonal growth patterns tend 
to be long-lived (Watkinson and White 1985, pp. 44-45; Tanner 2001, p. 
1980). Although stems may die and portions of the rhizome may 
disintegrate over time, except under extreme conditions enough of the 
rhizome survives from one growing season to the next to support 
continued growth of an individual plant. Also, because the plants 
produce very few if any seeds, the ability of the plant to disperse 
into and colonize previously unoccupied areas is diminished. Since this 
species was listed, no additional occurrences were documented in 
Mexico; the occurrences along the west coast of Baja California between 
Cabo Colonet and the U.S.-Mexico border are rapidly disappearing due to 
recreational development and agriculture (Dudek 2003, p. P-330).

Critical Habitat

Background

    Critical habitat is defined in section 3(5)(A) of the Act as:
    (1) The specific areas within the geographical area occupied by the 
species, at the time it is listed in accordance with the provisions of 
section 4 of the Act, on which are found those physical or biological 
features
    (a) Essential to the conservation of the species, and
    (b) Which may require special management considerations or 
protection; and
    (2) Specific areas outside the geographical area occupied by the 
species at the time it is listed, upon a determination by the Secretary 
of the Interior that such areas are essential for the conservation of 
the species.
    Conservation, as defined under section 3 of the Act, means the use 
of all methods and procedures that are necessary to bring an endangered 
or threatened species to the point at which the measures provided 
pursuant to the Act are no longer necessary. Such methods and 
procedures include, but are not limited to, all activities associated 
with scientific resources management such as research, census, law 
enforcement, habitat acquisition and maintenance, propagation, live 
trapping and transplantation, and in the extraordinary case where 
population pressures within a given ecosystem cannot otherwise be 
relieved, may include regulated taking.
    Critical habitat receives protection under section 7 of the Act 
through the prohibition against Federal agencies carrying out, funding, 
or authorizing activities that result in the destruction or adverse 
modification of critical habitat. Section 7(a)(2) requires consultation 
on Federal actions that may affect critical habitat. The designation of 
critical habitat does not affect land ownership or establish a refuge, 
wilderness, reserve, preserve, or other conservation area. Such 
designation does not allow the government or public to access private 
lands. Such designation does not require implementation of restoration, 
recovery, or enhancement measures by the landowner. Where a landowner

[[Page 44242]]

seeks or requests Federal agency funding or authorization for an 
activity that may affect a listed species or critical habitat, the 
consultation requirements of section 7(a)(2) would apply, but even in 
the event of a destruction or adverse modification finding, the Federal 
action agency's and the applicant's obligation is not to restore or 
recover the species, but to implement reasonable and prudent 
alternatives to avoid destruction or adverse modification of critical 
habitat.
    To be considered for inclusion in a critical habitat designation, 
habitat within the geographical area occupied by the species at the 
time of listing must contain physical and biological features that are 
essential to the conservation of the species, and be included only if 
those features may require special management considerations or 
protection. Critical habitat designations identify, to the extent known 
using the best scientific data available, habitat areas that provide 
essential life cycle needs of the species; that is, areas on which the 
physical and biological features are found laid out in the appropriate 
quantity and spatial arrangement essential to the conservation of the 
species. Under the Act and regulations at 50 CFR 424.12, we can 
designate as critical habitat areas outside the geographical area 
occupied by the species at the time it is listed only when we determine 
that those areas are essential for the conservation of the species and 
that designation limited to those areas occupied at the time of listing 
would be inadequate to ensure the conservation of the species.
    Section 4 of the Act requires that we designate critical habitat on 
the basis of the best scientific and commercial data available. 
Further, our Policy on Information Standards Under the Endangered 
Species Act (published in the Federal Register on July 1, 1994 (59 FR 
34271)), the Information Quality Act (section 515 of the Treasury and 
General Government Appropriations Act for Fiscal Year 2001 (Pub. L. 
106-554; H.R. 5658)), and our associated Information Quality 
Guidelines, provide criteria, establish procedures, and provide 
guidance to ensure that our decisions are based on the best scientific 
data available. They require our biologists, to the extent consistent 
with the Act and with the use of the best scientific data available, to 
use primary and original sources of information as the basis for 
recommendations to designate critical habitat.
    When we are determining which areas should be proposed as critical 
habitat, our primary source of information is generally the information 
developed during the listing process for the species. Additional 
information sources may include the recovery plan for the species, 
articles in peer-reviewed journals, conservation plans developed by 
States and counties, scientific status surveys and studies, biological 
assessments, or other unpublished materials and expert opinion or 
personal knowledge.
    Habitat is dynamic, and species may move from one area to another 
over time. We recognize that climate change may cause changes in the 
arrangement of occupied habitat patches. Current climate change 
predictions for terrestrial areas in the Northern Hemisphere indicate 
warmer air temperatures, more intense precipitation events, and 
increased summer continental drying (Field et al. 1999, pp. 1-3; Hayhoe 
et al. 2004, p. 12422; Cayan et al. 2005, p. 6; Intergovernmental Panel 
on Climate Change 2007, p. 11). However, predictions of climatic 
conditions for smaller subregions such as California remain uncertain. 
It is unknown at this time if climate change in California will result 
in a warmer trend with localized drying, higher precipitation events, 
or other effects. Thus, the information currently available on the 
effects of global climate change and increasing temperatures does not 
make sufficiently precise estimates of the location and magnitude of 
the effects, so we are unable to determine what, if any, additional 
areas would be needed. However, we recognize that critical habitat 
designated at a particular point in time may not include all of the 
habitat areas that we may later determine are necessary for the 
recovery of the species. For these reasons, a critical habitat 
designation does not signal that habitat outside the designated 
critical habitat area is unimportant or may not be required for 
recovery of the species.
    Areas that are important to the conservation of the species, but 
are outside the critical habitat designation, will continue to be 
subject to conservation actions implemented under section 7(a)(1) of 
the Act. Areas that support populations are also subject to the 
regulatory protections afforded by the section 7(a)(2) jeopardy 
standard, as determined on the basis of the best available scientific 
information at the time of the agency action. Federally funded or 
permitted projects affecting listed species outside their designated 
critical habitat areas may still result in jeopardy findings in some 
cases. Similarly, critical habitat designations made on the basis of 
the best available information at the time of designation will not 
control the direction and substance of future recovery plans, habitat 
conservation plans (HCPs), or other species conservation planning 
efforts if information available at the time of these planning efforts 
calls for a different outcome.

Physical and Biological Features

    In accordance with section 3(5)(A)(i) of the Act and regulations at 
50 CFR 424.12, in determining which areas within the geographical area 
occupied by the species at the time of listing to propose as critical 
habitat, we consider the physical and biological features that are 
essential to the conservation of the species and that may require 
special management considerations or protection. Those features are the 
primary constituent elements (PCEs) laid out in the appropriate 
quantity and spatial arrangement for the conservation of the species. 
The PCEs include, but are not limited to:
    (1) Space for individual and population growth and for normal 
behavior;
    (2) Food, water, air, light, minerals, or other nutritional or 
physiological requirements;
    (3) Cover or shelter;
    (4) Sites for breeding, reproduction, and rearing (or development) 
of offspring; and
    (5) Habitats that are protected from disturbance or are 
representative of the historical, geographical, and ecological 
distributions of a species.
    Little is known about the habitat specificity and characteristics 
of this species. Therefore, the PCEs for Ambrosia pumila are based on 
our assessment of the ecosystem settings in which the species has most 
frequently been detected.

Space for Individual and Population Growth and for Normal Behavior

Clonal Growth--Rhizome Spread and New Aerial Stems
    Individual Ambrosia pumila plants spread by underground rhizomes to 
produce a group of genetically identical aerial stems--a clone. Growing 
rhizomes extend underground beyond the extent of the aerial stems into 
adjacent suitable habitat, and rhizomes of adjacent plants likely 
intermingle to a degree. The distance rhizomes extend beyond the 
standing aerial stems is difficult to measure because of the difficulty 
in investigating an intact, underground rhizome system.
    The extent and configuration of the visible portion (aerial stems) 
of A. pumila patches can change from one growing season to the next 
(Martin 2005, p. 3; City of San Diego 2008a, p.

[[Page 44243]]

1). For example, see Figure 4 in Martin 2005, in which patches of A. 
pumila are shown to change in shape and size (up to several square 
meters) from 2000 to 2005, with some patches not producing any stems in 
2005 (some of the patches that did not produce stems in 2005 were 
observed to produce stems in 2008 (Folarin 2008, pers. comm.)). These 
changes in patch size and shape are perhaps due to differences in 
available moisture or competition from other plants (Martin 2005, p. 3; 
City of San Diego 2008a, p. 1). Based on these and other observations, 
we conclude that the rhizome system of a group of A. pumila stems 
likely occupies a greater underground area than occupied by the stems 
above ground at any given time, with aerial stems produced only where 
conditions are appropriate. Thus, to ensure that a habitat area does 
not exclude unseen underground portions of A. pumila plants, the area 
needs to include additional surface area beyond the visible surface 
area covered by the aerial stems.
Germination of Seeds and Spread of Seedlings
    It is unclear to what extent and with what frequency Ambrosia 
pumila reproduces by seed. Presuming at least low rates of sexual 
reproduction, space is needed for new plants to germinate, grow, and 
spread. However, we are not aware of any research that would provide 
the information needed to assess the species' germination and seedling 
needs.

Food, Water, Air, Light, Minerals, or Other Nutritional or 
Physiological Requirements

Water
    Specific water needs of the species are unknown. Ambrosia pumila is 
adapted to dry conditions which occur annually throughout its range 
(Keck 1959, p. 1103; Munz 1974, p. 112; Dudek 2000, Appendix A; CNLM 
2008, p. 18). Service biologists have observed green (not desiccated) 
aerial stem shoots after small amounts of precipitation and after 
annual vegetation in the area had desiccated, implying that either A. 
pumila requires less water than other grassland plants, that the 
underground perennial rhizome system has some capacity to store enough 
water to sustain growth, or both (Folarin 2008, pers. comm.). 
Additionally, we believe that periodic flooding may be necessary to 
some segment of the plant's life history (such as seed germination, 
dispersal of seeds and rhizomes) or to maintain some essential aspect 
of its habitat, because of the indicator that the plant is always found 
on river terraces or within the watersheds of vernal pools.
Light
    Ambrosia pumila is limited to open or low-growing plant 
communities, which implies that the species is not shade-tolerant 
(Dudek 2000, pp. 18-19). Ambrosia pumila stems amid taller vegetation 
obtain adequate sunlight by growing taller (etiolation) and more 
slender compared to those in more open areas (Dudek 2000, p. 19), which 
also implies the species is not shade-tolerant.
Soil
    Ambrosia pumila is found primarily on sandy loam or clay soils 
including (but not limited to) the Placentia (sandy loam), Diablo 
(clay), and Ramona (sandy loam) series (Dudek 2000, Appendix A; CNDDB 
2008). These soil types likely are particularly conducive to the growth 
and persistence of A. pumila because it is rarely found growing on 
other substrate types (such as gravel).
    Chemical soil attributes and other abiotic and biotic 
characteristics have been measured and documented for Ambrosia pumila 
occurrences at Skunk Hollow (Riverside County), and Mission Trails 
Regional Park and San Diego National Wildlife Refuge (San Diego County) 
(Dudek 2000, Appendix A; CNLM 2008, pp. 6-7, 12, and 18), including pH, 
percent organic matter, soil moisture, and elemental composition. These 
measurements did not provide consistent results across the range of the 
species; thus, we are unable to make generalizations as to needs of the 
species as far as soil attributes are concerned.
Temperature
    We have seen no reports of data on the tolerance of Ambrosia pumila 
to climatic extremes. Temperature is thought to potentially play a role 
in inducing (or prohibiting) seed germination (Johnson 1999, p. 5), 
although there is limited information at this time as to whether this 
species reproduces via seed.

Sites for Breeding, Reproduction, or Rearing (or Development) of 
Offspring

    As stated above under the ``Life History'' section, little is known 
about sexual reproduction in Ambrosia pumila. Because occurrences are 
consistently found on the upper terraces of rivers and other waterways, 
periodic flooding of these waterways likely plays or likely has played 
a role in the life history of the plant. For example, Johnson (1999, p. 
5) postulated that A. pumila seeds may require soaking in flood waters 
or scarification as they are churned about with debris in flood waters 
to germinate. Additionally, A. pumila may depend on floods to disperse 
rhizomes and seeds (Dudek 2003, p. P-332) and to create space for new 
stems by removing or limiting the growth of competitors.
    Presuming Ambrosia pumila is wind-pollinated, as discussed in the 
``Life History'' section above, the species requires sufficient airflow 
through inflorescences to pick up and carry pollen (McGlaughlin and 
Friars 2007, p. 329). This is another reason (in addition to not being 
shade-tolerant) that A. pumila may require habitat containing primarily 
low-growing plants--low-growing plants do not block or dramatically 
reduce airflow to plants of A. pumila's stature, which is generally 
less than 12 in (30 cm) tall (McGlaughlin and Friars 2007, p. 329).
    Ambrosia pumila is presumed to be self-compatible (an individual 
can produce viable seed using its own pollen), but this aspect of the 
species' reproductive strategy has not been well examined. In a recent 
study, another Ambrosia species previously thought to be self-
compatible was found not to be self-compatible (Friedman and Barrett 
2008, p. 4). If A. pumila likewise is not self-compatible, genetically 
distinct individuals in close proximity to one another may be crucial 
to maintaining sexual reproduction in the species (McGlaughlin and 
Friars 2007, p. 329).

Habitats Protected from Disturbance or Representative of the 
Historical, Geographical, and Ecological Distributions of the Species

    Ambrosia pumila occurs most frequently on upper terraces of rivers 
(flat or gently sloping areas of 0 to 42 percent slopes are typical for 
terraces on which A. pumila occurrences are found, near, but not 
directly adjacent to, the river channel) and other drainages in western 
Riverside County, western San Diego County, and northwestern Baja 
California (Beauchamp 1986, p. 94; Johnson et al. 1999, p. 1; 
McGlaughlin and Friar 2007, p. 321; CNDDB 2008). These areas are or 
have been associated with a natural flood disturbance regime. The 
species is primarily associated with grassland and ruderal communities, 
and openings in coastal sage scrub (Johnson et al. 1999, p. 1; Dudek 
2000, p. 18; Dudek 2003, p. P-330; CNDDB 2008). In Riverside County, A. 
pumila occurs in ruderal and nonnative grassland communities adjacent 
to creeks and other smaller drainages (for example, Temescal 
(Alberhill) Creek and Santa Gertrudis Creek) (Dudek 2003, p. P-326;

[[Page 44244]]

CNDDB 2008). Ambrosia pumila also occurs in nonnative grassland 
community adjacent to and within the watershed of Skunk Hollow vernal 
pool in Riverside County (Dudek 2003, p. P-326; CNDDB 2008). In San 
Diego County, A. pumila is more often found adjacent to larger 
waterways (for example, San Luis Rey River, San Diego River, and 
Sweetwater River), although the species is also often found associated 
with smaller drainages and washes (CNDDB 2008).
    Occurrences in Riverside County are found at much higher elevation 
than in San Diego County. For example, the occurrence at Skunk Hollow 
in Riverside County is 1,350 ft (411 m) above sea level, while the 
occurrences at Mission Trails Regional Park and San Diego National 
Wildlife Refuge in San Diego County are about 315 ft and 360 ft (96 m 
and 110 m) above sea level, respectively (CNLM 2008, p. 7)).
    The documented range of Ambrosia pumila in Mexico at the time of 
listing extended from Cabo Colonet south to Lake Chapala in north-
central Baja California. We have no information regarding additional 
occurrences in Mexico, or the physical and biological features 
essential to the conservation of the species there.

Primary Constituent Elements for Ambrosia pumila

    Under the Act and its implementing regulations, we are required to 
identify the known physical and biological features, called primary 
constituent elements (PCEs), within the geographical area occupied by 
Ambrosia pumila at the time of listing that are essential to the 
conservation of the species and which may require special management 
considerations or protection. Again, the physical and biological 
features are those PCEs laid out in a specific spatial arrangement and 
quantity determined to be essential to the conservation of the species. 
Because not much is known about the specific needs and characteristics 
of this species, the PCEs are based on observed traits of the habitat 
types in which the species is most often found. All areas we are 
proposing as critical habitat for A. pumila were occupied at the time 
the species was listed, occur within the species' historical geographic 
range, and contain physical and biological features to support at least 
one life-history function.
    Based on the above needs and our current knowledge of the life 
history, biology, and ecology of Ambrosia pumila, and the 
characteristics of the areas where the species is known to occur, we 
have identified two PCEs for A. pumila:
    1. Sandy loam or clay soils (regardless of disturbance status), 
including (but not limited to) the Placentia (sandy loam), Diablo 
(clay), and Ramona (sandy loam) soil series that occur on near (but not 
directly adjacent to) a river, creek, or other drainage, or within the 
watershed of a vernal pool, and that occur on an upper terrace (flat or 
gently sloping areas of 0 to 42 percent slopes are typical for terraces 
on which A. pumila occurrences are found).
    2. Grassland or ruderal habitat types, or openings within coastal 
sage scrub, on the soil types and topography described in PCE 1, that 
provide adequate sunlight, and airflow for wind pollination.
    Based on our current knowledge of the needs of the species, we 
believe the need for space for individual and population growth and 
normal behavior is met by PCE 2, and areas for reproduction, water, 
light, and soil are provided by PCEs 1 and 2. These areas provide 
nutrients, moisture, and proximity to water features that provide 
periodic flooding presumed necessary for the plant's persistence.
    With this proposed designation of critical habitat, we intend to 
conserve the physical and biological features that are essential to 
support the life-history functions that are the basis for the proposal. 
All units and subunits proposed in this rule as critical habitat 
contain sufficient PCEs in the appropriate quantity and spatial 
arrangement to provide for one or more of the life-history functions of 
A. pumila.
    We are soliciting public comment for information to help us more 
specifically identify PCEs and essential habitat for Ambrosia pumila. 
There is a lack of available information regarding what constitutes 
essential habitat for this species. Additionally, the available 
information does not identify a consistent pattern in specific life-
history requirements and habitat types where Ambrosia pumila is found. 
For these reasons, the PCEs in this proposed rule are broad and based 
on our assessment of the ecosystem settings in which the species has 
most frequently been detected and speculation regarding its life 
history. We specifically seek information that may assist us in 
defining those physical and biological features essential to the 
conservation of the species which may require special management 
considerations or protection, or in identifying specific areas outside 
the geographical area occupied by the species at the time it was listed 
that may be essential to the conservation of the species (see questions 
2 and 3 in the Public Comments section).

Special Management Considerations or Protection

    When designating critical habitat, we assess whether the physical 
and biological features within the geographical area occupied by the 
species at the time of listing contain features that are essential to 
the conservation of the species and that may require special management 
considerations or protection. All areas proposed for designation as 
critical habitat will require some level of management to address the 
current and future threats to the physical and biological features 
essential to the conservation of Ambrosia pumila. In all units, special 
management will be required to ensure that the habitat is able to 
provide for the growth and reproduction of the species.
    Researchers estimate that Ambrosia pumila historically was known 
from over 50 locations in San Diego and Riverside Counties, but the 
number of extant occurrences has been dramatically reduced as much of 
its habitat has been impacted by human activities (Burrascano and Hogan 
1997, p. 7; Dudek 2000, p. 17; CNDDB 2008). A detailed discussion of 
threats to A. pumila and its habitat can be found in the final listing 
rule (67 FR 44372). The primary threats impacting the physical and 
biological features essential to the conservation of A. pumila that may 
require special management considerations or protection within the 
proposed critical habitat include, but are not limited to, the 
following (67 FR 44372):
    <bullet> Habitat destruction caused by urban development, including 
highway and utility corridor construction and maintenance, highway 
expansion, and development of recreational facilities (such as golf 
courses and campgrounds). These activities can remove the PCEs by 
removing soil (by grading) and changing Ambrosia pumila habitat to 
urban land, which is unsuitable for the species.
    <bullet> Soil compaction caused by the creation of trails by 
hikers, horses, and vehicles. Ambrosia pumila appears to be tolerant to 
some level of disturbance caused by trail creation and use; it is often 
found in the disturbed areas along margins of dirt trails. However, it 
is found less often on trails, implying that although the appropriate 
soil type might be present, soil compaction can alter the physical 
characteristics of the soil such that the soil can no longer support 
growth of the plant.

[[Page 44245]]

    <bullet> Habitat alteration caused by nonnative plant species that 
may, if present in large enough numbers, change the plant community to 
the extent that A. pumila plants can no longer receive adequate 
sunlight and airflow.
    <bullet> Alteration of hydrology and floodplain dynamics (such as 
channelization and water diversions) (an additional threat not 
discussed in the listing rule), which can change the frequency of 
flooding in occupied areas or eliminate periodic flooding presumed 
necessary for the plant's persistence altogether, or change groundwater 
levels that could change the plant community to the extent that A. 
pumila plants can no longer receive adequate sunlight and airflow.
    Special management considerations or protection are required within 
critical habitat areas to address these threats. Management activities 
that could ameliorate these threats include fencing Ambrosia pumila 
occurrences and providing signage to discourage encroachment by hikers, 
horses, and off road vehicle users; control of nonnative plants using 
methods shown to be effective (for examples, see CNLM 2008); guiding 
the design of development projects to avoid impacts to A. pumila 
habitat; and restoring and maintaining hydrology and floodplain 
dynamics of waterways associated with A. pumila occurrences where 
feasible.
    The designation of critical habitat does not imply that lands 
outside of critical habitat do not play an important role in the 
conservation of Ambrosia pumila. Federal activities that may affect 
areas outside of critical habitat are still subject to review under 
section 7 of the Act if they may affect A. pumila. The prohibitions of 
section 9 of the Act applicable to listed plant species also continue 
to apply both inside and outside of designated critical habitat.

Criteria Used To Identify Critical Habitat

    As required by section 4(b) of the Act, we used the best scientific 
and commercial data available in determining areas within the 
geographical area occupied at the time of listing that contain the 
features essential to the conservation of Ambrosia pumila, and areas 
outside of the geographical area occupied at the time of listing that 
are essential to the conservation of A. pumila, or both. All essential 
areas were occupied at the time of listing, as discussed below. As a 
result, we are not currently proposing any areas outside the 
geographical area presently occupied by A. pumila because we have 
determined that including only occupied areas in critical habitat is 
sufficient for the conservation of the species. In San Diego County, 
where the pattern of extirpated occurrences reflects a loss of 
occurrences from each of the watersheds in which the species occurs 
rather than a complete loss from those watersheds, the areas occupied 
at the time of listing include the known historical range of the 
species (CNDDB 2008). In Riverside County, the loss of an occurrence 
near the Riverside Airport reflects a loss to the geographical extent 
of the range in that county (Provance and Sanders 2001, p. 47).
    We also reviewed available information that pertains to the habitat 
requirements of this species, although A. pumila has not been well 
studied and little is known about its habitat specificity, 
characteristics, and breeding system. Additionally, data from different 
information sources at times conflict, further complicating the task of 
discerning the specific habitat requirements of the species. We used 
numerous sources of information, such as materials and data included in 
reports submitted to the Service during section 7 consultations and 
other project reviews, and by biologists holding section 10(a)(1)(A) 
recovery permits; research published in peer-reviewed articles and 
presented in academic theses and agency reports; regional Geographic 
Information System (GIS) coverages for area calculations and mapping; 
and data collected in the field by Service biologists.
    We are proposing to designate critical habitat in areas that we 
determined were occupied by the species at the time of listing, and 
that contain the PCEs in the quantity and spatial arrangement to 
support life history functions essential to the conservation of the 
species. This includes two areas occupied by occurrences detected after 
Ambrosia pumila was listed. We have concluded that these areas were 
occupied at the time the species was listed because individuals of 
species with a clonal growth habit like A. pumila are usually long-
lived (Watkinson and White 1985, pp. 44-45; Tanner 2001, p. 1980). The 
occurrence near Santa Gertrudis Creek was found during a survey for a 
subtransmission line project in 2006 (AMEC 2006, p. 12). The occurrence 
at the intersection of State Route 76 and Olive Hill Road was found 
during a general survey for A. pumila in 2006 (CNDDB 2008). To our 
knowledge, the areas had not been surveyed for A. pumila previously, 
and we have no reason to believe the plant was imported or had 
dispersed into these areas from other areas after A. pumila was listed. 
The occurrences identified since listing likely were in existence for 
many years and were only recently detected due to increased awareness 
of this species.
    We are also proposing to designate critical habitat in some areas 
where A. pumila was thought to be extirpated or where, though extant, 
A. pumila was not considered viable at the time of listing. We 
conducted surveys of historical occurrences as part of the background 
research for this proposed rule. We found one documented occurrence 
area east of Lake Hodges in San Diego County that was thought to be 
extirpated or nonviable because the occurrence had not been seen since 
1999, and because records did not contain sufficient information to 
locate the occurrence site. Our survey found this site does contain a 
viable occurrence of A. pumila and meets the criteria set out in this 
rule for A. pumila critical habitat. The site was located after the 
species was listed and found to contain a large population of A. 
pumila. We are not proposing to designate any areas outside the 
geographical area occupied by the species at the time of listing, and 
all of the areas we are proposing to designate are currently occupied 
by the species. All units and subunits proposed contain the PCEs 
believed to be essential to the conservation of this species.

Methods

    As required by section 4(b)(1)(A) of the Act, we use the best 
scientific and commercial data available in trying to determine areas 
that contain the features that are essential to the conservation of 
Ambrosia pumila. We used the best scientific data available to select 
areas that we believe may possess those physical and biological 
features essential to the conservation of the species, and that may 
require special management considerations or protection.
    After identifying the PCEs, we followed these steps to delineate 
critical habitat:
    (1) We identified areas occupied by Ambrosia pumila at the time of 
listing as extant occurrences, where an occurrence is defined as an 
occupied habitat area separated by 0.25 mi (0.40 km) or more from the 
next nearest occupied habitat area.
    (2) We determined that due to the lack of specific information 
regarding the needs of the species, we are unable to identify specific 
areas outside the geographical area occupied by the species at the time 
it was listed that may be essential to the conservation of the species.

[[Page 44246]]

    (3) We removed all areas where the species occurs in habitat of low 
quality for growth and propagation (such as pavement areas or cracks 
within paved areas). Although occupied, we believe these occurrences 
are not capable of providing for the full life-history requirements of 
this species and are not likely to contribute to its long-term 
conservation; therefore, we did not consider these locations as 
containing essential features as habitat and did not include them in 
critical habitat.
    (4) To define an outer boundary for each patch that captures the 
existing underground rhizome system (which extends beyond the visible 
aerial stems of plants within each occurrence), we added the average 
distance between the visible (aerial stems) portions of each Ambrosia 
pumila patch and the next nearest patch to the limits of the visible 
portion of each patch. Using GIS data, we found the average distance 
between clusters of stems in adjacent patches to be approximately 1,181 
ft (260 m), and we added this distance to the visible outer limit of 
each occurrence to delineate the presumed expanse of the occurrence 
that also includes the underground rhizomes.
    (5) We removed any area within the outer boundary of an occurrence 
where habitat type was not grassland, ruderal, or coastal sage scrub.
    We describe how we implemented each of the steps above in detail 
below.
    (1) We identified all occurrences of Ambrosia pumila--those known 
to exist at the time of listing and those detected since listing. We 
compiled data from the following sources to create our database of A. 
pumila occurrences: (1) Data used in the 2002 listing rule for A. 
pumila (67 FR 44372; July 2, 2002); (2) the California Natural 
Diversity Database occurrence data report for A. pumila and 
accompanying GIS records (CNDDB 2008, pp. 1-49); (3) the data from the 
Consortium of California Herbaria and accompanying Berkeley Mapper GIS 
records (Consortium of California Herbaria 2008, pp. 1-5); (4) the 
Western Riverside County Multiple Species Habitat Conservation Plan 
(Western Riverside County MSHCP) species GIS database; and (5) the 
Carlsbad Fish and Wildlife Office's internal species GIS database, 
which includes the species data used for the San Diego Multiple Species 
Conservation Program (MSCP) and the San Diego Multiple Habitat 
Conservation Plan (MHCP), reports from section 7 consultations, and 
Service observations of A. pumila (CFWO internal species GIS database). 
As discussed in detail earlier in this section, we consider all extant 
occurrences to have been in existence at the time of listing. We used 
these data to delineate GIS polygons around Ambrosia pumila 
occurrences.
    We reviewed the data that we compiled to ensure its accuracy. We 
checked each data point in our database to ensure that it represented a 
site documented by a herbarium voucher or observation of Ambrosia 
pumila and was not a duplicate voucher or observation of another 
occurrence in the database. Duplicates were removed from our database. 
Secondly, we checked each data point to ensure that it was correctly 
mapped. Data points that did not match the description for the original 
herbarium collection or observation were remapped in the correct 
location, if possible. We removed observations where the location could 
not be determined from available data or site visits.
    We then determined which areas are currently occupied. For areas 
where we have past occupancy data for Ambrosia pumila, we assumed the 
area remains occupied unless: (1) Three or more surveys for the species 
did not find A. pumila; (2) the site was significantly disturbed (for 
example, converted to development) since the last observation of the 
species at that location; or (3) specific location information for the 
site was lacking, and field surveys carried out in conjunction with 
this proposed critical habitat determination could not locate the 
occurrence.
    (2) We determined that there are no specific areas outside the 
geographical area occupied by the species at the time it was listed 
that are essential to the conservation of the species. Information 
found during the Service's research in connection with this proposed 
action indicated that the geographical area occupied by the species at 
the time it was listed provides sufficient resources for the 
conservation of the species. We do not have sufficient information 
regarding the specific needs of the species to determine if any 
unoccupied areas are essential for the conservation of the species.
    (3) We removed areas where Ambrosia pumila occurs in habitat of low 
quality for growth and propagation (such as pavement areas or cracks 
within paved areas). Although occupied, we did not consider these 
locations for critical habitat, as these occurrences are not likely to 
contribute to the long-term conservation of the species. We made this 
determination using site descriptions in the California Natural 
Diversity Database, talking to Service biologists, other researchers, 
and land managers familiar with the areas in question, and visiting and 
evaluating sites in person.
    (4) We estimated the distance that the root system of an occurrence 
likely extends beyond the aboveground extent of the occurrence by 
measuring the distance of each GIS polygon representing an Ambrosia 
pumila patch to the nearest neighboring patch. As mentioned above, an 
occurrence is defined by CNDDB as an occupied habitat area separated by 
0.25 mi (0.40 km) or more from next nearest occupied habitat area. A 
patch is defined herein as a distinct cluster of stems within an 
occurrence. We estimated the average distance of underground rhizome 
expansion beyond the aboveground aerial stems as 1,181 ft (260 m). We 
expanded the outer boundary of the above-ground extent of each 
occurrence by 1,181 ft (260 m) to account for the underground rhizome 
system extending beyond the area occupied by visible stems. We believe 
this method adequately captures the extent of individual occurrences.
    (5) We removed any areas within the expanded outer boundary of an 
occurrence where habitat type was not grassland, ruderal, or open areas 
within coastal sage scrub habitat, using the habitat types assigned to 
relevant areas in our GIS database, and personal observations of sites 
by Service biologists and other researchers or land managers.
    Based on the results of this methodology, we are proposing to 
designate 7 units that include 8 subunits as critical habitat for 
Ambrosia pumila. After applying the above criteria and methods, we 
mapped the critical habitat unit boundaries at each of these seven 
units as GIS polygons around known occurrences. Critical habitat 
boundaries were delineated as polygons encompassing the extent of 
habitat believed to contain the physical and biological features 
essential to the conservation of the species that may require special 
management considerations or protection.
    When determining the proposed critical habitat boundaries, we made 
every effort to avoid including developed areas such as lands occupied 
by buildings, paved areas, and other structures that lack PCEs for 
Ambrosia pumila. The scale of the maps we prepared under the parameters 
for publication within the Code of Federal Regulations may not reflect 
the exclusion of such developed areas. Any developed structures and the 
land under them inadvertently left inside critical habitat boundaries 
shown on the maps of this proposed critical habitat are excluded by 
text in this rule and are not proposed for critical habitat 
designation. Therefore, if the critical habitat is

[[Page 44247]]

finalized as proposed, Federal actions involving these lands would not 
trigger section 7 consultation with respect to critical habitat and the 
requirement of no adverse modification unless the specific actions 
would affect the species or PCEs in adjacent critical habitat.
    We are soliciting public comment for information that may assist us 
in defining those physical and biological features essential to the 
conservation of the species which may require special management 
considerations or protection, or in identifying specific areas outside 
the geographical area occupied by the species at the time it was listed 
that may be essential to the conservation of the species (see questions 
2 and 3 in the Public Comments section).

Proposed Critical Habitat Designation

    We determined that approximately 802 ac (324 ha) meet our 
definition of critical habitat for Ambrosia pumila, including lands 
under Federal, State, other government, and private ownership. We are 
proposing 7 units that include 8 subunits as critical habitat for A. 
pumila. Table 1 identifies the approximate area of each proposed 
critical habitat unit and subunit by landownership.

                                                                  Table 1--Proposed critical habitat units for Ambrosia pumila.
                                                            Area estimates reflect all land within critical habitat unit boundaries.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
  Location  (California Natural            Federally Owned Land            State or Local Government Owned Land            Privately Owned Land                         Total Area
    Diversity Database(CNDDB)    ---------------------------------------------------------------------------------------------------------------------------------------------------------------
       Occurrence Number)                acres             hectares              acres             hectares              acres             hectares              acres             hectares
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                        RIVERSIDE COUNTY
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Unit 1: Temescal Creek watershed  --                  --                  23.4                9.5                 88.4                35.8                111.8               45.3
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1A. Alberhill (\*\)               --                  --                  23.4                9.5                 18.0                7.3                 41.4                16.8
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1B. Nichols Road (44)             --                  --                  --                  --                  70.4                28.5                70.4                28.5
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Unit 2: Skunk Hollow Vernal Pool  --                  --                  --                  --                  118.1               47.8                118.1               47.8
 watershed (22)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Unit 3: Santa Gertrudis Creek     --                  --                  --                  --                  32.5                13.2                32.5                13.2
 watershed (55)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
      SUBTOTAL:                   --                  --                  23.4                9.5                 239.0               96.8                262.4               106.3
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                        SAN DIEGO COUNTY
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Unit 4: San Luis Rey River        --                  --                  2.4                 1.0                 102.5               41.5                104.9               42.5
 watershed
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
4A. Calle de la Vuelta (43)       --                  --                  --                  --                  29.6                12.0                29.6                12.0
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
4B. Olive Hill Road (16)          --                  --                  0.3                 0.1                 34.8                14.1                35.0                14.2
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
4C. Jeffries Ranch (45)           --                  --                  2.2                 0.9                 38.1                15.4                40.3                16.3
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Unit 5: San Dieguito River        --                  --                  15.8                6.4                 5.3                 2.2                 21.2                8.6
 watershed - Lake Hodges (14)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Unit 6: San Diego River           --                  --                  171.5               69.4                26.4                10.7                197.8               80.1
 watershed - Mission Trails
 Regional Park (12)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Unit 7: Sweetwater River          145.5               58.9                12.6                5.1                 57.1                23.1                215.2               87.1
 watershed
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
7A. Jamul Road (1)                --                  --                  2.5                 1.0                 36.4                14.7                38.9                15.7
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
7B. San Diego National Wildlife   117.6               47.6                --                  --                  15.0                6.1                 132.5               53.6
 Refuge (48)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
7C. Steele Canyon Bridge (34)     27.9                11.3                10.1                4.1                 5.8                 2.3                 43.7                17.7
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
      SUBTOTAL:                   145.5               58.9                202.3               81.9                191.3               77.4                539.1               218.2
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
              TOTAL               145.5               58.9                225.7               91.4                430.4               174.2               801.6               324.4
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
\*\ Occurrence not entered in CNDDB.
\**\Values in this table may not sum due to rounding.

    The areas we are proposing as critical habitat currently provide 
all habitat components necessary to meet the primary biological needs 
of Ambrosia pumila, as defined by the physical and biological features 
essential to the conservation of the species. These areas constitute 
our best assessment of areas determined to be occupied at the time of 
listing that contain the PCEs for A. pumila that may require special 
management considerations or protection. We are not proposing any 
unoccupied areas or areas outside of the species' historical range 
because we

[[Page 44248]]

determined that occupied lands within the species' historical range are 
sufficient for the conservation of A. pumila. Each unit and subunit 
includes suitable habitat that will allow for population growth and 
growth of aerial stems from parts of the root system.
    Presented below are brief descriptions of all subunits and reasons 
why they meet the definition of critical habitat for Ambrosia pumila. 
The subunits are listed in order geographically north to south and east 
to west.

Unit 1: Temescal Creek Watershed

    Unit 1 is located in western Riverside County and consists of two 
subunits totaling approximately 23 ac (10 ha) of County-owned land, and 
88 ac (36 ha) of private land, for a total of approximately 112 ac (45 
ha) (values do not sum due to rounding).
Subunit 1A: Alberhill
    Subunit 1A is located near Alberhill, north of Lake Elsinore and 
just west of Interstate Highway 15 in Riverside County, California. 
This subunit is near the northern base of Alberhill Mountain, east of 
Lake Street, and south of Temescal Creek (also called Alberhill Creek). 
Subunit 1A consists of approximately 23 ac (10 ha) of County owned 
land, and 18 ac (7 ha) of privately owned land, for a total of 
approximately 41 ac (17 ha). This subunit (along with subunit 1B) 
represents the northernmost occurrence of this species, which is 
geographically situated to assist this species expand its range 
northward. Like all other extant occurrences, this subunit is also 
essential to the conservation of this species because of its 
contribution to the genetic diversity of the species (McGlaughlin and 
Friar 2007, p. 329). This subunit was occupied at the time of listing 
and remains occupied. Subunit 1A contains physical and biological 
features that are essential to the conservation of A. pumila, including 
sandy loam or clay soils located on an upper terrace of a water source, 
which provide nutrients, moisture, and periodic flooding presumed 
necessary for the plant's persistence (PCE 1); and ruderal habitat 
type, which allows adequate sunlight and airflow for A. pumila (PCE 2). 
The physical and biological features essential to the conservation of 
the species in this subunit may require special management 
considerations or protection to address threats from nonnative plant 
species in situations where nonnative species are outcompeting A. 
pumila for resources, and from human encroachment that occurs in the 
area. The County-owned portions of Subunit 1A are conserved and are 
being managed for the County by the Western Riverside County Regional 
Conservation Authority in accordance with Western Riverside MSHCP 
guidelines. Please see the ``Special Management Considerations or 
Protection'' section of this proposed rule for a discussion of the 
threats to A. pumila habitat and potential management considerations.
Subunit 1B: Nichols Road
    Subunit 1B is located about 2.1 mi (3.5 km) southeast of Subunit 1A 
(Alberhill), on the north and south sides of Nichols Road, in Riverside 
County, California. This subunit is near the southeastern base of 
Alberhill Mountain, just west of Durant Road and Temescal Creek. 
Subunit 1B consists of approximately 70 ac (28 ha) of privately owned 
land. This subunit was occupied at the time of listing and remains 
occupied, and is essential to the conservation of this species because 
this subunit (along with subunit 1A) represents the northernmost 
occurrences of this species, which is geographically situated to 
potentially assist this species expand its range northward. Like all 
other extant occurrences, this subunit is also essential to the 
conservation of this species because of its contribution to the genetic 
diversity of the species (McGlaughlin and Friar 2007, p. 329). However, 
due to impacts from unauthorized grading and disking, and a permitted 
road realignment project, A. pumila within this subunit may be in 
imminent danger of extirpation. Subunit 1B contains physical and 
biological features that are essential to the conservation of Ambrosia 
pumila, including sandy loam or clay soils located on an upper terrace 
of a water source, which provide nutrients, moisture, and periodic 
flooding presumed necessary for the plant's persistence (PCE 1), and 
ruderal habitat type, which allows adequate sunlight and airflow for A. 
pumila (PCE 2). The physical and biological features essential to the 
conservation of the species in this subunit may require special 
management considerations or protection to address threats from 
nonnative plant species in situations where nonnative species are 
outcompeting A. pumila for resources, and from activities (grading, 
construction, human encroachment) that occur in the area. Please see 
the ``Special Management Considerations or Protection'' section of this 
proposed rule for a discussion of the threats to A. pumila habitat and 
potential management considerations.

Unit 2: Skunk Hollow Vernal Pool Watershed

    Unit 2 is located in the Barry Jones (Skunk Hollow) Wetland 
Mitigation Bank in unincorporated Riverside County. The mitigation bank 
is located east of the City of Murrieta and is loosely bounded by 
Browning Street on the north, the edge of an unnamed canyon on the 
east, Murrieta Hot Springs Road on the south, and Pourroy Avenue on the 
west. Unit 2 consists of approximately 118 ac (48 ha) of privately 
owned land managed by Center for Natural Lands Management. This unit, 
like all other extant occurrences, is essential to the conservation of 
Ambrosia pumila because of its contribution to the genetic diversity of 
the species (McGlaughlin and Friar 2007, p. 329). This unit was 
occupied at the time of listing and remains occupied. Unit 2 contains 
physical and biological features that are essential to the conservation 
of A. pumila, including sandy loam or clay soils located on an upper 
terrace of a water source, which provide nutrients, moisture, and 
periodic flooding presumed necessary for the plant's persistence (PCE 
1), and annual grassland habitat type, which allows adequate sunlight 
and airflow for A. pumila (PCE 2). The physical and biological features 
essential to the conservation of the species in this subunit require 
continued special management considerations or protection to address 
threats from nonnative plant species in situations where nonnative 
species are outcompeting A. pumila for resources, and human 
encroachment. The Center for Natural Lands Management is providing 
needed management by maintaining fencing around the area to protect the 
area from encroachment, and carrying out research to determine the best 
method for control of nonnative plant species on-site. Please see the 
``Special Management Considerations or Protection'' section of this 
proposed rule for a discussion of the threats to A. pumila habitat and 
potential management considerations.

Unit 3: Santa Gertrudis Creek Watershed (55)

    Unit 3 is located about 1 mile (1.6 km) southwest of Unit 2, along 
the San Diego Aqueduct, south of the intersection of Chandler and Suzi 
Roads and north of Santa Gertrudis Creek in Riverside County. Unit 3 
consists of approximately 32 ac (13 ha) of privately owned land. This 
unit was occupied at the time of listing and remains occupied, and, 
like all other extant

[[Page 44249]]

occurrences, is essential to the conservation of this species because 
of its contribution to the genetic diversity of the species 
(McGlaughlin and Friar 2007, p. 329). Unit 3 contains physical and 
biological features that are essential to the conservation of A. 
pumila, including sandy loam or clay soils located on an upper terrace 
of a water source, which provide nutrients, moisture, and periodic 
flooding presumed necessary for the plant's persistence (PCE 1), and 
ruderal habitat type, which allows adequate sunlight and airflow for A. 
pumila (PCE 2). The physical and biological features essential to the 
conservation of the species in this unit may require special management 
considerations or protection to address threats from nonnative plant 
species in situations where nonnative species are outcompeting A. 
pumila for resources, human encroachment, and utility maintenance 
activities. Please see the ``Special Management Considerations or 
Protection'' section of this proposed rule for a discussion of the 
threats to A. pumila habitat and potential management considerations.

Unit 4: San Luis Rey River Watershed

    Unit 4 is located in northwestern San Diego County and consists of 
three subunits of approximately 2 ac (1 ha) of State or local 
government owned land and approximately 103 ac (41 ha) of privately 
owned land, for a total of approximately 105 ac (42 ha).
Subunit 4A: Calle de la Vuelta
    Subunit 4A is located near junction of State Route 76 and Calle de 
la Vuelta in unincorporated San Diego County. Subunit 4A consists of 
approximately 30 ac (12 ha) of privately owned land. This subunit was 
occupied at the time of listing and remains occupied, and, like all 
other extant occurrences, is essential to the conservation of this 
species because of its contribution to the genetic diversity of the 
species (McGlaughlin and Friar 2007, p. 329). Subunit 4A contains 
physical and biological features that are essential to the conservation 
of Ambrosia pumila, including sandy loam or clay soils located on an 
upper terrace of a water source, which provide nutrients, moisture, and 
periodic flooding presumed necessary for the plant's persistence (PCE 
1), and ruderal habitat type, which allows adequate sunlight and 
airflow for A. pumila (PCE 2). The physical and biological features 
essential to the conservation of the species in this subunit may 
require special management considerations or protection to address 
threats from nonnative plant species in situations where nonnative 
species are outcompeting A. pumila for resources, human encroachment, 
road maintenance activities, and future widening of State Route 76. 
Please see the ``Special Management Considerations or Protection'' 
section of this proposed rule for a discussion of the threats to A. 
pumila habitat and potential management considerations.
Subunit 4B: Olive Hill Road
    Subunit 4B is located on the west side of State Route 76, south of 
Olive Hill Road in unincorporated San Diego County. Subunit 4B consists 
of approximately 0.3 ac (0.1 ha) of State or local government owned 
land and approximately 35 ac (14 ha) of privately owned land, for a 
total of approximately 35 ac (14 ha) (values do not sum due to 
rounding). The occurrence in this subunit was considered extirpated at 
the time of listing, but has since been found to be extant. Like all 
other extant occurrences, it is essential to the conservation of this 
species because of its contribution to the genetic diversity of the 
species (McGlaughlin and Friar 2007, p. 329). Subunit 4B contains 
physical and biological features that are essential to the conservation 
of Ambrosia pumila, including sandy loam or clay soils located on an 
upper terrace of a water source, which provide nutrients, moisture, and 
periodic flooding presumed necessary for the plant's persistence (PCE 
1), and grassland habitat type which allow adequate sunlight and 
airflow for A. pumila (PCE 2). The physical and biological features 
essential to the conservation of the species in this subunit may 
require special management considerations or protection to address 
threats from nonnative plant species in situations where nonnative 
species are outcompeting A. pumila for resources, human encroachment, 
road maintenance activities, and future widening of State Route 76. 
Please see the ``Special Management Considerations or Protection'' 
section of this proposed rule for a discussion of the threats to A. 
pumila habitat and potential management considerations.
Subunit 4C: Jeffries Ranch
    Subunit 4C is located approximately 0.7 mile (1.1 km) southwest of 
Bonsall Bridge, adjacent to the south side of State Route 76 in the 
City of Oceanside, San Diego County. Subunit 4C consists of 
approximately 2 ac (1 ha) of State or local government owned land and 
approximately 38 ac (15 ha) of privately owned land, for a total of 
approximately 40 ac (16 ha). This subunit was occupied at the time of 
listing and remains occupied, and, like all other extant occurrences, 
is essential to the conservation of this species because of its 
contribution to the genetic diversity of the species (McGlaughlin and 
Friar 2007, p. 329). Subunit 4C contains physical and biological 
features that are essential to the conservation of Ambrosia pumila, 
including sandy loam or clay soils located on an upper terrace of a 
water source, which provide nutrients, moisture, and periodic flooding 
presumed necessary for the plant's persistence (PCE 1), and nonnative 
grassland habitat type, which allows adequate sunlight and airflow for 
A. pumila (PCE 2). The physical and biological features essential to 
the conservation of the species in this subunit may require special 
management considerations or protection to address threats from 
nonnative plant species in situations where nonnative species are 
outcompeting A. pumila for resources, human encroachment, road and 
utility maintenance activities, future widening of State Route 76, and 
potential development. Please see the ``Special Management 
Considerations or Protection'' section of this proposed rule for a 
discussion of the threats to A. pumila habitat and potential management 
considerations.

Unit 5: San Dieguito River Watershed--Lake Hodges

    Unit 5 is located on the west side of Interstate 15, just north of 
Lake Hodges and south of Via Rancho Parkway in San Diego County. Unit 5 
consists of approximately 16 ac (6 ha) of local government owned land 
and approximately 5 ac (2 ha) of privately owned land, for a total of 
approximately 21 ac (9 ha) (values do not sum due to rounding). This 
unit was occupied at the time of listing, remains occupied, and, like 
all other extant occurrences, is essential to the conservation of this 
species because of its contribution to the genetic diversity of the 
species (McGlaughlin and Friar 2007, p. 329). Unit 5 contains physical 
and biological features that are essential to the conservation of 
Ambrosia pumila, including sandy loam or clay soils located on an upper 
terrace of a water source, which provide nutrients, moisture, and 
periodic flooding presumed necessary for the plant's persistence (PCE 
1), and nonnative grassland habitat type, which allows adequate 
sunlight and airflow for A. pumila (PCE 2). The physical and biological 
features essential to the conservation of the species in this unit

[[Page 44250]]

may require special management considerations or protection to address 
threats from nonnative plant species in situations where nonnative 
species are outcompeting A. pumila for resources, human encroachment, 
utility maintenance activities, and potential development. Please see 
the ``Special Management Considerations or Protection'' section of this 
proposed rule for a discussion of the threats to A. pumila habitat and 
potential management considerations.

Unit 6: San Diego River Watershed--Mission Trails Regional Park

    Unit 6 is located in Mission Trails Regional Park in the City of 
San Diego. This unit includes three areas: (1) South of Old Mission Dam 
and Father Junipero Serra Trail and west of Simeon Drive; (2) north of 
Old Mission Dam and the San Diego River, and northwest of Simeon Drive; 
and (3) immediately east of Kumeyaay Campground, north of Mission Gorge 
Road, east of Bushy Hill Drive, and south of the San Diego River. Unit 
6 consists of approximately 172 ac (69 ha) of land owned and managed by 
the City of San Diego, and approximately 26 ac (11 ha) of privately 
owned land, for a total of 198 ac (80 ha). This unit was occupied at 
the time of listing and remains occupied, and like all other extant 
occurrences, is essential to the conservation of this species because 
of its contribution to the genetic diversity of the species 
(McGlaughlin and Friar 2007, p. 329). Unit 6 contains physical and 
biological features that are essential to the conservation of A. 
pumila, including sandy loam or clay soils located on an upper terrace 
of a water source, which provide nutrients, moisture, and periodic 
flooding presumed necessary for the plant's persistence (PCE 1), and 
nonnative grassland habitat type, which allows adequate sunlight and 
airflow for A. pumila (PCE 2). The physical and biological features 
essential to the conservation of the species in this unit may require 
special management considerations or protection to address threats from 
nonnative plant species in situations where nonnative species are 
outcompeting A. pumila for resources, and human encroachment. Please 
see the ``Special Management Considerations or Protection'' section of 
this proposed rule for a discussion of the threats to A. pumila habitat 
and potential management considerations.

Unit 7: Sweetwater River Watershed

    Unit 7 is located in southwestern San Diego County and consists of 
three subunits containing approximately 146 ac (60 ha) of federally 
owned land (San Diego National Wildlife Refuge), approximately 13 ac (5 
ha) of State or local government owned land, and approximately 57 ac 
(23 ha) of privately owned land, for a total of approximately 215 ac 
(87 ha) (values do not sum due to rounding).
Subunit 7A: Jamul Road
    Subunit 7A is located southeast of the City of El Cajon at and near 
junction of Jamul Road and Steele Canyon Road, on the north and south 
sides of Jamul Road. Subunit 7A consists of approximately 2 ac (1 ha) 
of State or local government owned land, and approximately 36 ac (15 
ha) of privately owned land, for a total of approximately 39 ac (16 ha) 
(values do not sum due to rounding). This subunit was occupied at the 
time of listing and remains occupied, and, like all other extant 
occurrences, is essential to the conservation of this species because 
of its contribution to the genetic diversity of the species 
(McGlaughlin and Friar 2007, p. 329). Subunit 7A contains physical and 
biological features that are essential to the conservation of A. 
pumila, including sandy loam or clay soils located on an upper terrace 
of a water source, which provide nutrients, moisture, and periodic 
flooding presumed necessary for the plant's persistence (PCE 1), and 
nonnative grassland habitat type, which allows adequate sunlight and 
airflow for A. pumila (PCE 2). The physical and biological features 
essential to the conservation of the species in this subunit may 
require special management considerations or protection to address 
threats from nonnative plant species in situations where nonnative 
species are outcompeting A. pumila for resources, alterations of site 
hydrology, and off-highway-vehicle use. Please see the ``Special 
Management Considerations or Protection'' section of this proposed rule 
for a discussion of the threats to A. pumila habitat and potential 
management considerations.
Subunit 7B: San Diego National Wildlife Refuge
    Subunit 7B is located primarily on the San Diego National Wildlife 
Refuge, south of Sweetwater River between Rancho San Diego Golf Course 
and the hills to the south, and on the north and south sides of a dirt 
trail adjoining the end of Par Four Drive in unincorporated San Diego 
County. Subunit 7B consists of approximately 118 ac (48 ha) of Federal 
land owned and managed by the Fish and Wildlife Service and 
approximately 15 ac (6 ha) of privately owned land, for a total of 
approximately 133 ac (54 ha). This subunit was occupied at the time of 
listing and remains occupied, and is essential to the conservation of 
this species because of its contribution to the genetic diversity of 
the species (McGlaughlin and Friar 2007, p. 329). Subunit 7B contains 
physical and biological features that are essential to the conservation 
of A. pumila, including sandy loam or clay soils located on an upper 
terrace of a water source, which provide nutrients, moisture, and 
periodic flooding presumed necessary for the plant's persistence (PCE 
1), and nonnative grassland habitat type, which allows adequate 
sunlight and airflow for A. pumila (PCE 2). The physical and biological 
features essential to the conservation of the species in this subunit 
may require special management considerations or protection on 
privately owned lands, and continued management and protection on 
federally owned lands to address threats from nonnative plant species 
in situations where nonnative species are outcompeting A. pumila for 
resources, and human encroachment. Please see the ``Special Management 
Considerations or Protection'' section of this proposed rule for a 
discussion of the threats to A. pumila habitat and potential management 
considerations.
Subunit 7C: Steele Canyon Bridge
    Subunit 7C is located mainly on the east side of State Route 94 on 
a slope between a concrete-lined ditch and a fence adjacent and 
parallel to State Route 94, approximately 0.7 mile (1.1 km) southeast 
of Subunit 7B, in unincorporated San Diego County. A small portion of 
the subunit is located on the opposite side of State Route 94 just 
south of Steele Canyon Bridge in a split-rail exclosure. Subunit 7C 
consists of approximately 28 ac (11 ha) of federally owned land managed 
by the Fish and Wildlife Service, approximately 10 ac (4 ha) of State 
(California Department of Transportation) and local (County of San 
Diego) government owned land, and approximately 6 ac (2 ha) of 
privately owned land, for a total of approximately 44 ac (18 ha) 
(values do not sum due to rounding). This subunit was occupied at the 
time of listing and remains occupied. Like all other extant 
occurrences, it is essential to the conservation of this species 
because of its contribution to the genetic diversity of the species 
(McGlaughlin and Friar 2007, p. 329). Subunit 7C contains physical and 
biological features that are essential to the conservation of Ambrosia 
pumila, including sandy loam or clay soils located on an upper terrace 
of a water source, which provide

[[Page 44251]]

nutrients, moisture, and periodic flooding presumed necessary for the 
plant's persistence (PCE 1), and nonnative grassland habitat type, 
which allows adequate sunlight and airflow for A. pumila (PCE 2). The 
physical and biological features essential to the conservation of the 
species in this subunit may require special management considerations 
or protection on State, local government, and privately owned lands, 
and continued management and protection on federally owned lands to 
address threats from nonnative plant species in situations where 
nonnative species are outcompeting A. pumila for resources, and human 
encroachment. Please see the ``Special Management Considerations or 
Protection'' section of this proposed rule for a discussion of the 
threats to A. pumila habitat and potential management considerations.

Effects of Critical Habitat Designation

Section 7 Consultation

    Section 7(a)(2) of the Act requires Federal agencies, including the 
Service, to ensure that actions they fund, authorize, or carry out are 
not likely to destroy or adversely modify critical habitat. Decisions 
by the 5th and 9th Circuit Courts of Appeal have invalidated our 
definition of ``destruction or adverse modification'' (50 CFR 402.02) 
(see Gifford Pinchot Task Force v. U.S. Fish and Wildlife Service, 378 
F. 3d 1059 (9th Cir 2004) and Sierra Club v. U.S. Fish and Wildlife 
Service et al., 245 F.3d 434, 442F (5th Cir 2001)), and we do not rely 
on this regulatory definition when analyzing whether an action is 
likely to destroy or adversely modify critical habitat. Under the 
statutory provisions of the Act, we determine destruction or adverse 
modification on the basis of whether, with implementation of the 
proposed Federal action, the affected critical habitat would remain 
functional (or retain the current ability for the PCEs to be 
functionally established) to serve its intended conservation role for 
the species (Service 2004a, p.3). Section 7(a)(2) of the Act requires 
Federal agencies, including the Service, to evaluate their actions with 
respect to any species that is endangered or threatened and with 
respect to its critical habitat, if any is proposed or designated. 
Regulations implementing this interagency cooperation provision of the 
Act are codified at 50 CFR part 402.
    Section 7(a)(4) of the Act requires Federal agencies to confer with 
us on any action that is likely to jeopardize the continued existence 
of a species proposed for listing or result in destruction or adverse 
modification of proposed critical habitat. Conference reports provide 
conservation recommendations to assist the agency in eliminating 
conflicts that may be caused by the proposed action. We may issue a 
formal conference report if requested by a Federal agency. Formal 
conference reports on proposed critical habitat contain an opinion that 
is prepared according to 50 CFR 402.14, as if critical habitat were 
designated. We may adopt the formal conference report as the biological 
opinion when the critical habitat is designated, if no substantial new 
information or changes in the action alter the content of the opinion 
(see 50 CFR 402.10(d)). The conservation recommendations in a 
conference report or opinion are advisory.
    If a species is listed or critical habitat is designated, section 
7(a)(2) of the Act requires Federal agencies to ensure that activities 
they authorize, fund, or carry out are not likely to jeopardize the 
continued existence of such a species or to destroy or adversely modify 
its critical habitat. If a Federal action may affect a listed species 
or its critical habitat, the responsible Federal agency (action agency) 
must enter into consultation with us. As a result of this consultation, 
we document compliance with the requirements of section 7(a)(2) through 
our issuance of:
    1. A concurrence letter for Federal actions that may affect, but 
are not likely to adversely affect, listed species or critical habitat; 
or
    2. A biological opinion for Federal actions that may affect, and 
are likely to adversely affect, listed species or critical habitat.
    An exception to the concurrence process referred to in (1) above 
occurs in consultations involving National Fire Plan projects. In 2004, 
the U.S. Forest Service and the U.S. Bureau of Land Management (BLM) 
reached agreements with the Service to streamline a portion of the 
section 7 consultation process (BLM-ACA 2004, pp. 1-8; FS-ACA 2004, pp. 
1-8). The agreements allow the U.S. Forest Service and the Bureau of 
Land Management the opportunity to make ``not likely to adversely 
affect'' determinations for projects implementing the National Fire 
Plan. Such projects include prescribed fire, mechanical fuels 
treatments (thinning and removal of fuels to prescribed objectives), 
emergency stabilization, burned area rehabilitation, road maintenance 
and operation activities, ecosystem restoration, and culvert 
replacement actions. The U.S. Forest Service and the Bureau of Land 
Management must insure staff is properly trained, and both agencies 
must submit monitoring reports to the Service to determine if the 
procedures are being implemented properly and effects on endangered 
species and their habitats are being properly evaluated. As a result we 
do not believe the alternative consultation processes being implemented 
as a result of the National Fire Plan will differ significantly from 
those consultations being conducted by the Service.
    If we issue a biological opinion concluding that a project is 
likely to jeopardize the continued existence of a listed species or 
destroy and/or adversely modify critical habitat, we also provide 
reasonable and prudent alternatives to the project, if any are 
identifiable. We define ``reasonable and prudent alternatives'' at 50 
CFR 402.02 as alternative actions identified during consultation that:
    <bullet> Can be implemented in a manner consistent with the 
intended purpose of the action,
    <bullet> Can be implemented consistent with the scope of the 
Federal agency's legal authority and jurisdiction,
    <bullet> Are economically and technologically feasible, and
    <bullet> Would, in the Director's opinion, avoid jeopardizing the 
continued existence of the listed species or destroying or adversely 
modifying critical habitat.
    Reasonable and prudent alternatives can vary from slight project 
modifications to extensive redesign or relocation of the project. Costs 
associated with implementing a reasonable and prudent alternative are 
similarly variable.
    Regulations at 50 CFR 402.16 require Federal agencies to reinitiate 
consultation on previously reviewed actions in instances where we have 
listed a new species or subsequently designated critical habitat that 
may be affected and the Federal agency has retained discretionary 
involvement or control over the action (or the agency's discretionary 
involvement or control is authorized by law). Consequently, Federal 
agencies may sometimes need to request reinitiation of consultation 
with us on actions for which formal consultation has been completed, if 
those actions with discretionary involvement or control may affect 
subsequently listed species or designated critical habitat.
    Federal activities that may affect Ambrosia pumila or its 
designated critical habitat require section 7 consultation under the 
Act. Activities on State, Tribal, local, or private lands requiring a 
Federal permit (such as a

[[Page 44252]]

permit from the U.S. Army Corps of Engineers under section 404 of the 
Clean Water Act (33 U.S.C. 1251 et seq.) or a permit from us under 
section 10 of the Act) or involving some other Federal action (such as 
funding from the Federal Highway Administration, Federal Aviation 
Administration, or the Federal Emergency Management Agency) are subject 
to the section 7 consultation process. Federal actions not affecting 
listed species or critical habitat, and actions on State, Tribal, 
local, or private lands that are not federally funded, authorized, or 
permitted, do not require section 7 consultations.

Application of the Adverse Modification Standard

    The key factor related to the adverse modification determination is 
whether, with implementation of the proposed Federal action, the 
affected critical habitat would continue to serve its intended 
conservation role for the species, or would retain its current ability 
for the PCEs to be functionally established. Activities that may 
destroy or adversely modify critical habitat are those that alter the 
physical and biological features (PCEs) to an extent that appreciably 
reduces the conservation value of critical habitat for Ambrosia pumila. 
Generally, the conservation role of the A. pumila proposed critical 
habitat units is to support the various life-history needs and provide 
for the conservation of the species.
    Section 4(b)(8) of the Act requires us to briefly evaluate and 
describe in any proposed or final regulation that designates critical 
habitat those activities involving a Federal action that may destroy or 
adversely modify such habitat, or that may be affected by such 
designation. Activities that may destroy or adversely modify critical 
habitat may also jeopardize the continued existence of the species.
    Activities that, when carried out, funded, or authorized by a 
Federal agency, may adversely affect critical habitat and therefore 
should result in consultation for Ambrosia pumila include actions that 
would adversely affect the species' exposure to adequate moisture, 
nutrients, sunlight, airflow, and periodic flooding. For example:
    (1) Actions that would alter the configuration of the water sources 
associated with Ambrosia pumila habitat or the upper terraces where A. 
pumila habitat is found. Such activities could include, but are not 
limited to, water impoundment, stream channelization, water diversion, 
water withdrawal, and development activities. These activities could 
alter the biological and physical features that provide the appropriate 
habitat for A. pumila by altering or eliminating flooding events that 
this species may rely on for dispersal, seed germination, and control 
of competitors; reducing or increasing the availability of groundwater 
that may result in a shift of habitat type to a community unsuitable 
for A. pumila (shrub- or tree-dominated habitat, which would inhibit 
exposure to needed sunlight and airflow); or causing increased erosion 
that could remove soils appropriate for A. pumila growth.
    (2) Activities that remove soils appropriate for A. pumila growth 
such as plowing or grading, or activities that change the 
characteristics of soils so that A. pumila growth is impeded, such as 
soil compaction due to hiking and vehicle use also adversely affect 
critical habitat.
    We consider all of the units and subunits proposed as critical 
habitat to contain features essential to the conservation of Ambrosia 
pumila. All units are within the geographic range of the species, were 
occupied at the time of listing, and are currently occupied by A. 
pumila. To ensure that their actions do not jeopardize the continued 
existence of A. pumila, Federal agencies already consult with us on 
activities in areas currently occupied by A. pumila, or in unoccupied 
areas if the species may be affected by their actions.

Exemptions

Application of Section 4(a)(3) of the Act

    The Sikes Act Improvement Act of 1997 (Sikes Act) (16 U.S.C. 670a) 
required each military installation that includes land and water 
suitable for the conservation and management of natural resources to 
complete an integrated natural resources management plan (INRMP) by 
November 17, 2001. An INRMP integrates implementation of the military 
mission for the installation with stewardship of the natural resources 
found on the base. Each INRMP includes:
    <bullet> An assessment of the ecological needs on the installation, 
including the need to provide for the conservation of listed species;
    <bullet> A statement of goals and priorities;
    <bullet> A detailed description of management actions to be 
implemented to provide for these ecological needs; and
    <bullet> A monitoring and adaptive management plan.
    Among other things, an INRMP must, to the extent appropriate and 
applicable, provide for fish and wildlife management; fish and wildlife 
habitat enhancement or modification; wetland protection, enhancement, 
and restoration where necessary to support fish and wildlife; and 
enforcement of applicable natural resource laws.
    The National Defense Authorization Act for Fiscal Year 2004 (Pub. 
L. No. 1088-136) amended the Endangered Species Act to limit areas 
eligible for designation as critical habitat. Specifically, section 
4(a)(3)(B)(i) of the Act (16 U.S.C. 1533(a)(3)(B)(i)) now provides: 
``The Secretary shall not designate as critical habitat any lands or 
other geographical areas owned or controlled by the Department of 
Defense, or designated for its use, that are subject to an integrated 
natural resources management plan prepared under section 101 of the 
Sikes Act (16 U.S.C. 670a), if the Secretary determines in writing that 
such plan provides a benefit to the species for which critical habitat 
is proposed for designation.''
    There are no Department of Defense lands with a completed INRMP 
within the proposed critical habitat designation. Therefore, there are 
no lands that meet the criteria for being exempted from the designation 
of critical habitat pursuant to section 4(a)(3) of the Act.

Exclusions

Application of Section 4(b)(2) of the Act

    Section 4(b)(2) of the Act states that the Secretary must designate 
or revise critical habitat on the basis of the best available 
scientific data after taking into consideration the economic impact, 
national security impact, and any other relevant impact of specifying 
any particular area as critical habitat. The Secretary may exclude an 
area from critical habitat if he determines that the benefits of such 
exclusion outweigh the benefits of specifying such area as part of the 
critical habitat, unless he determines, based on the best scientific 
data available, that the failure to designate such area as critical 
habitat will result in the extinction of the species. In making that 
determination, the legislative history is clear that the Secretary has 
broad discretion regarding which factor(s) to use and how much weight 
to give to any factor.
    Under section 4(b)(2) of the Act, in considering whether to exclude 
a particular area from the designation, we must identify the benefits 
of including the area in the designation, identify the benefits of 
excluding the area from the designation, and determine whether the 
benefits of exclusion outweigh the benefits of inclusion. If, based on 
this analysis, we determine that the benefits

[[Page 44253]]

of exclusion outweigh the benefits of inclusion, we can exclude the 
area only if such exclusion would not result in the extinction of the 
species.
Exclusions Based on Habitat Conservation Plans (HCPs)
    Under section 4(b)(2) of the Act, we consider any other relevant 
impacts, in addition to economic impacts and impacts to national 
security. We consider a number of factors including whether the 
landowners have developed any HCPs or other management plans for the 
area, or whether there are conservation partnerships that would be 
encouraged by designation of, or exclusion from, critical habitat. In 
addition, we look at any Tribal issues, and consider the government-to-
government relationship of the United States with Tribal entities. We 
also consider any social impacts that might occur because of the 
designation.
    In the following sections, we address a number of general issues 
that are relevant to the exclusions we are considering. Additionally, 
we are preparing a draft economic analysis of the impacts of the 
proposed critical habitat designation and related factors, which will 
be available for public review and comment when it is complete. Based 
on public comment on that document and the proposed designation itself, 
as well as the information in the final economic analysis, the 
Secretary may exclude from critical habitat areas different from those 
identified for possible exclusion in this proposed rule under the 
provisions of section 4(b)(2) of the Act, up to and including all areas 
proposed for designation. This is also addressed in our implementing 
regulations at 50 CFR 424.19.
    Ambrosia pumila is a covered species under the Western Riverside 
County Multiple Species Habitat Conservation Plan (Western Riverside 
County MSHCP), the City of San Diego Subarea Plan under the Multiple 
Species Conservation Program (MSCP), and the County of San Diego 
Subarea Plan under the MSCP. We are considering exclusion of lands 
covered by each of these plans. Portions of the proposed critical 
habitat subunits may warrant exclusion from the proposed designation of 
critical habitat under section 4(b)(2) of the Act based on the 
partnerships, management, and protection afforded under these approved 
and legally operative HCPs. In this proposed rule, we are seeking input 
from the stakeholders in these HCPs, peer reviewers, and the public as 
to whether or not we should exclude these areas from the final critical 
habitat designation. Below is a brief description of each plan and the 
lands proposed as critical habitat that are covered by each plan.
Western Riverside County Multiple Species Habitat Conservation Plan 
(Western Riverside County MSHCP)
    The Western Riverside County MSHCP is a large-scale, multi-
jurisdictional HCP encompassing about 1.26 million ac (510,000 ha) in 
western Riverside County. The Western Riverside County MSHCP plan area 
encompasses Units 1, 2, and 3 of proposed critical habitat for Ambrosia 
pumila. The Western Riverside County MSHCP addresses 146 listed and 
unlisted ``covered species,'' including A. pumila. Participants in the 
Western Riverside County MSHCP include 14 cities; the County of 
Riverside, including the Riverside County Flood Control and Water 
Conservation Agency (County Flood Control), Riverside County 
Transportation Commission, Riverside County Parks and Open Space 
District, and Riverside County Waste Department; California Department 
of Parks and Recreation; and the California Department of 
Transportation. The Western Riverside County MSHCP was designed to 
establish a multi-species conservation program that minimizes and 
mitigates the expected loss of habitat and the incidental take of 
covered species. On June 22, 2004, the Service issued a single 
incidental take permit (TE-088609-0) under section 10(a)(1)(B) of the 
Act to 22 permittees under the MSHCP for a period of 75 years.
    The Western Riverside County MSHCP will establish approximately 
153,000 ac (61,917 ha) of new conservation lands (Additional Reserve 
Lands) to complement the approximate 347,000 ac (140,426 ha) of pre-
existing natural and open space areas (Public/Quasi-Public lands). 
These Public/Quasi-Public lands include those under Federal ownership, 
primarily managed by the U.S. Forest Service and Bureau of Land 
Management, and also permittee-owned open-space areas (such as State 
parks, County Flood Control, and county park lands). Collectively, the 
Additional Reserve Lands and Public/Quasi-Public lands form the overall 
Western Riverside County MSHCP Conservation Area. The precise 
configuration of the 153,000 ac (61,916 ha) of Additional Reserve Lands 
is not mapped or identified in the MSHCP, but rather is based on 
textual descriptions of a Conceptual Reserve Design within the bounds 
of a 310,000 ac (125,453 ha) ``Criteria Area'' that is interpreted as 
implementation of the MSHCP proceeds.
    Specific conservation objectives stated in the Western Riverside 
County MSHCP for Ambrosia pumila include conserving at least 21,800 ac 
(8,822 ha) of occupied or suitable habitat for the species. This goal 
will be attained through acquisition or other dedications of land 
assembled from within the Criteria Area (i.e., the Additional Reserve 
Lands) or Narrow Endemic Plan Species Survey Area and through 
coordinated management of existing Public/Quasi-Public lands. We mapped 
a ``Conceptual Reserve Design'' that illustrates existing Public/Quasi-
Public lands and predicts the geographic distribution of the Additional 
Reserve Lands based on our interpretation of the textual descriptions 
of habitat conservation necessary to meet MSHCP conservation goals. Our 
Conceptual Reserve Design was intended to predict one possible future 
configuration of 153,000 ac (61,916 ha) of Additional Reserve Lands in 
conjunction with the existing Public/Quasi-Public lands, including 
approximately 21,800 ac (8,822 ha) of ``suitable'' A. pumila habitat, 
that will be conserved to meet the goals and objectives of the plan 
(Service 2004b, p. 73).
    Preservation and management of approximately 21,800 ac (8,822 ha) 
of suitable Ambrosia pumila habitat under the Western Riverside County 
MSHCP will contribute to conservation and ultimate recovery of this 
species. Ambrosia pumila is threatened primarily by habitat loss due to 
urbanization, flood control, and nonnative species competition (Service 
2004b, pp. 334-342). The Western Riverside County MSHCP aims to remove 
or reduce threats to this species and its PCEs as the plan is 
implemented by placing large blocks of occupied and unoccupied habitat 
into preservation throughout the Conservation Area. Areas identified 
for conservation include the occurrences at the Barry Jones (Skunk 
Hollow) Wetland Mitigation Bank (Unit 2), and the occurrence near 
Temescal Creek at Nichols Road (Subunit 1B). Additionally, the Western 
Riverside County MSHCP anticipated conservation of a third occurrence 
(Subunit 1A), near Temescal Creek east of Lake Street, in accordance 
with its Narrow Endemics Policy (Dudek 2003, pp. P-327-P-328).
    Additionally, the Western Riverside County MSHCP requires surveys 
for A. pumila as part of the project review process for public and 
private project proposals where suitable habitat is present within a 
defined narrow endemic species survey area (see Narrow Endemic Species 
Survey Area

[[Page 44254]]

Map, Figure 6-1 of the Western Riverside County MSHCP, Volume I in 
Dudek 2003). For locations with positive survey results, 90 percent of 
those portions of the property that provide long-term conservation 
value for the species will be avoided until it is demonstrated that the 
conservation objectives for the species are met (see Additional Survey 
Needs and Procedures; Western Riverside County MSHCP, Volume 1, section 
6.3.2 in Dudek 2003).
    The survey requirements, avoidance and minimization measures, and 
management for Ambrosia pumila (and its PCEs) provided for in the 
Western Riverside County MSHCP are expected to benefit this species on 
public and private lands covered by the plan. We are considering the 
exclusion of approximately 263 ac (106 ha) of private lands and 
permittee-owned or controlled Public/Quasi-Public lands in Units 1 
(Subunits 1A and 1B), 2, and 3 within the Western Riverside County 
MSHCP Plan Area from the final critical habitat designation under 
section 4(b)(2) of the Act. The Western Riverside County MSHCP has 
several measures in place to ensure the plan is implemented in a way 
that conserves Ambrosia pumila in accordance with the species-specific 
criteria and objectives for this species. Projects in the areas 
proposed as critical habitat conducted or approved by Western Riverside 
County MSHCP permittees are subject to the conservation requirements of 
the MSHCP. For projects that may impact A. pumila, various policies 
(including the Narrow Endemic Plant Species Policy (in Dudek 2003)) may 
provide additional conservation requirements.
    The Western Riverside County MSHCP incorporates many processes that 
allow for Service oversight and participation in program 
implementation. These processes include: (1) Consultation with the 
Service on a long-term management and monitoring plan; (2) submission 
of annual monitoring reports; (3) annual status meetings with the 
Service; and (4) submission of annual implementation reports to the 
Service (Service 2004b, pp. 9-10). Below we provide a brief analysis of 
the lands in Units 1, 2, and 3 that we are considering for exclusion 
and how each area is covered by the Western Riverside County MSHCP or 
other conservation measures.
    We are considering to exclude from critical habitat designation 
three Units that are within the boundaries of the Western Riverside 
County MSHCP. Within Unit 1, the County-owned portion of Subunit 1A is 
conserved and is currently managed for the County of Riverside by the 
Western Riverside County Regional Conservation Authority; transfer of 
ownership to the Western Riverside County Regional Conservation 
Authority is planned for the near future. Subunit 1B is on privately 
owned lands and is not currently conserved or managed for A. pumila. It 
is also within the Western Riverside County MSHCP Criteria Area, but 
not within the Narrow Endemic Plan Species Survey Area. Unit 2 is on 
privately owned lands and is conserved and managed by the Center for 
Natural Lands Management as part of the Barry Jones (Skunk Hollow) 
Wetland Mitigation Bank. Unit 3 is on privately owned lands and is not 
currently conserved or managed for A. pumila. It is not within the 
Western Riverside County MSHCP Criteria Area or the Narrow Endemic Plan 
Species Survey Area.
    The approximate amount of land that meets the definition of 
critical habitat for Ambrosia pumila within the Western Riverside 
County MSHCP and conservation status of those lands is summarized in 
Table 2.

  Table 2--Lands under the Western Riverside County Multiple Species Habitat Conservation Plan (MSHCP) that meet the definition of critical habitat for
                                                                    Ambrosia pumila.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                   Within Western Riverside County MSHCP      Within MSHCP Conservation Area       Outside of Conceptual Reserve Design
                                 --------------------------------------------------------------------------------        but Within Criteria Area
          Unit/Subunit                                                                                           ---------------------------------------
                                         acres             hectares              acres             hectares              acres             hectares
--------------------------------------------------------------------------------------------------------------------------------------------------------
1A. Alberhill                     41.4                16.8                23.4                9.5                 34.9                14.1
--------------------------------------------------------------------------------------------------------------------------------------------------------
1B. Nichols Road                  70.4                28.5                0.0                 0.0                 1.1                 0.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unit 2: Skunk Hollow Vernal Pool  118.1               47.8                7.0                 2.8                 0.0                 0.0
 watershed
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unit 3: Santa Gertrudis Creek     32.5                13.2                0.0                 0.0                 0.0                 0.0
 watershed
--------------------------------------------------------------------------------------------------------------------------------------------------------
      Totals:                     262.5               106.2               30.4                12.3                36.0                14.6
--------------------------------------------------------------------------------------------------------------------------------------------------------
\*\ Values in this table may not sum due to rounding.

    In summary, we are considering exclusion of approximately 263 ac 
(106 ha) of Ambrosia pumila habitat on private lands and permittee-
owned or controlled lands in Subunits 1A and 1B and Units 2 and 3 that 
meet the definition of critical habitat for A. pumila within the 
Western Riverside County MSHCP under section 4(b)(2) of the Act. The 
2002 final listing rule for A. pumila identified the following primary 
threats to A. pumila: habitat destruction and fragmentation caused by 
urban development; highway and utility corridor construction, 
expansion, and maintenance; sheep grazing; human encroachment on foot, 
horses, and vehicles; weed abatement and fire suppression practices 
(including mowing in mid summer to early fall when mowing would remove 
flowering portions of the aerial stems, discing, and plowing); 
stochastic events such as fire or drought; and competition from 
nonnative plant species (67 FR 44372). The implementation of the 
Western Riverside County MSHCP helps to address these threats through a 
regional planning effort, and outlines species-specific objectives and 
criteria for the conservation of A. pumila. We will analyze the 
benefits of inclusion and exclusion of this area from critical habitat 
under section 4(b)(2) of the Act. We encourage any public comment in 
relation to our consideration of the areas in Units 1, 2, and 3 for 
inclusion or exclusion (see Public Comments section above).

[[Page 44255]]

San Diego Multiple Species Conservation Program (MSCP)--City and County 
of San Diego's Subarea Plans
    The MSCP Plan is a framework HCP that has been in place for more 
than a decade. The plan area encompasses approximately 582,243 ac 
(235,626 ha) (County of San Diego 1997, p. 1-1; MSCP 1998, pp. 2-1, and 
4-2 to 4-4) and provides for conservation of 85 federally listed and 
sensitive species (``covered species'') through the establishment and 
management of approximately 171,920 ac (69,574 ha) of preserve lands, 
including lands within the Multi-Habitat Planning Area (MHPA; City of 
San Diego) and the Pre-Approved Mitigation Areas (PAMA; County of San 
Diego). The MSCP was developed in support of applications for 
incidental take permits for several federally listed species by 12 
participating jurisdictions and many other stakeholders in southwestern 
San Diego County. Under the umbrella of the MSCP, each of the 12 
participating jurisdictions is required to prepare a subarea plan that 
implements the goals of the MSCP within that particular jurisdiction. 
Ambrosia pumila was evaluated in the County of San Diego and the City 
of San Diego Subarea Plans. We are considering exclusion of lands 
within the City of San Diego and County of San Diego Subarea Plans. 
Specifically, we are considering the exclusion of 278 ac (113 ha) in 
Unit 5, Unit 6, Subunit 7A, and non-federally owned portions of 7B and 
7C (see Tables 3 and 4).
    Those areas of the MSCP preserve that are already conserved, as 
well as those areas that are designated for inclusion in the preserve 
under the plan, are referred to as the ``preserve area'' in this 
proposed critical habitat designation. Upon completion of preserve 
assembly by the end of the permit term, approximately 171,920 ac 
(69,574 ha) of the 582,243-ac (235,626-ha) MSCP plan area will be 
preserved (MSCP 1998, pp. 2-1, and 4-2 to 4-4). The City of San Diego's 
preserve is delineated by mapped preserve boundaries referred to as 
``hardline'' boundaries (the Multi-Habitat Planning Area). Most of the 
County of San Diego preserve areas do not have ``hardline'' boundaries, 
but the County's subarea plan identifies areas where mitigation 
activities should be focused to assemble its preserve areas (the Pre-
Approved Mitigation Areas).
    When the MSCP preserve is completed, the public sector (Federal, 
State, and local government, and general public) will have contributed 
approximately 108,750 ac (44,010 ha) (63.3 percent) to the preserve. 
Approximately 81,750 ac (33,083 ha) (48 percent) was existing public 
land when the MSCP was established and at least 27,000 ac (10,927 ha) 
(16 percent) will have been acquired. At completion, the private sector 
will have contributed at least 63,170 ac (25,564 ha) (37 percent) to 
the preserve as part of the development process, either through 
avoidance of impacts or as compensatory mitigation for impacts to 
biological resources. Federal and State governments, local 
jurisdictions and special districts, and managers of privately owned 
lands currently and in the future will manage and monitor their lands 
in the preserve for species and habitat protection (MSCP 1998, pp. 2-1, 
and 4-2 to 4-4).
    Private lands within the Multi-Habitat Planning Area and Pre-
Approved Mitigation Areas are subject to special restrictions on 
development, and lands that are dedicated to the preserve must be 
permanently protected and managed to conserve the covered species. 
Public lands owned by the Cities, County, State of California, and the 
Federal Government that are identified for conservation under the MSCP 
must also be protected and permanently managed to conserve the covered 
species.
    Numerous processes are incorporated into the MSCP that allow 
Service oversight of the MSCP implementation. For example, the MSCP 
imposes annual reporting requirements, provides for Service review and 
approval of proposed subarea plan amendments and preserve boundary 
adjustments, and provides for Service review and comment on projects 
during the California Environmental Quality Act review process. We also 
chair the MSCP Habitat Monitoring Subcommittee (MSCP 1998, pp. 5-11 to 
5-23). Each MSCP subarea plan must account annually for the progress it 
is making in assembling conservation areas and show that preserve 
assembly is in rough step with the development allowed in each 
jurisdiction. We must receive annual reports that include, both by 
project and cumulatively, the habitat acreage lost and conserved within 
the subareas. This accounting process ensures that habitat conservation 
proceeds in rough proportion to habitat loss and in compliance with the 
MSCP subarea plans and the plans' associated implementing agreements.
    The subarea plans under the MSCP contain requirements to monitor 
and adaptively manage Ambrosia pumila habitats and provide for the 
conservation of this species' PCEs. The framework and area-specific 
management plans are required to be comprehensive and address a broad 
range of management needs at the preserve and species levels that are 
intended to reduce the threats to covered species and thereby 
contribute to the recovery of the species. These plans are to include 
the following: (1) Fire management; (2) public access control; (3) 
fencing and gates; (4) ranger patrol; (5) trail maintenance; (6) 
visitor, interpretive, and volunteer services; (7) hydrological 
management; (8) signage and lighting; (9) trash and litter removal; 
(10) access road maintenance; (11) enforcement of property and 
homeowner requirements; (12) removal of invasive species; (13) 
nonnative predator control; (14) species monitoring; (15) habitat 
restoration; (16) management for diverse age classes of covered 
species; (17) use of herbicides and rodenticides; (18) biological 
surveys; (19) research; and (20) species management conditions (MSCP 
1998, p. 49-97).
    To protect Ambrosia pumila habitat, the City and County of San 
Diego subarea plans require that development be configured in a manner 
that minimizes impacts to sensitive biological resources and species 
covered by those plans (Service 1997, p. 10; Service 1998b, p. 7). The 
City of San Diego Subarea Plan requires preservation of 90 percent of 
the occurrence of A. pumila at Mission Trails Regional Park, additional 
impact avoidance and other measures as required under the MSCP Plan for 
narrow endemic species, and area-specific management directives 
designed to maintain long-term survival in the planning area (Service 
1997, pp. 104-105). Under the City of San Diego's subarea plan, impacts 
to narrow endemic plants, including A. pumila, inside the Multi-Habitat 
Planning Area will be avoided, and outside the Multi-Habitat Planning 
Area will be protected as appropriate by: (1) Avoidance of impacts; (2) 
management; (3) enhancement; and/or (4) transplantation to areas 
identified for preservation (City of San Diego 1997, p. 105-106; 
Service 1997, p. 15).
    The County of San Diego Subarea Plan provides three levels of 
protection for Ambrosia pumila. First, the Plan requires conservation 
of 87 to 100 percent of A. pumila occurrences in the County Subarea. 
Second, area-specific management directives must be designed for A. 
pumila to maintain long-term survival in the planning area (Service 
1997, pp. 104-105). Third, the County Subarea Plan dictates that on 
category 3 lands (lands for which the County Plan has not delineated 
preserve and development boundaries), any

[[Page 44256]]

newly discovered occurrences of A. pumila will be protected by impact 
avoidance measures required under the County's Biological Mitigation 
Ordinance. Narrow endemic plants, including A. pumila, are conserved 
under the Biological Mitigation Ordinance using a process that: (1) 
Requires avoidance to the maximum extent feasible; (2) allows for a 
maximum 20 percent encroachment into a population if total avoidance is 
not feasible; and (3) requires in-kind mitigation at 1-to-1 to 3-to-1 
ratios for impacts if avoidance and minimization of impacts would 
preclude reasonable use of the property (County of San Diego 1997, p. 
11; Service 1998b, p. 12).
    These measures help protect Ambrosia pumila and its essential 
habitat whether located on lands targeted for preserve status within 
the Multi-Habitat Planning Area and Pre-Approved Mitigation Areas or 
located outside of those areas in the City and County of San Diego 
Subareas. The narrow endemic policy for both the City and County of San 
Diego subarea plans require in situ conservation of A. pumila or 
mitigation to ameliorate any habitat loss. Therefore, although some 
losses may occur to this species on lands that are not currently 
preserved or otherwise designated for conservation under the MSCP, the 
preservation, conservation, and management of A. pumila provided under 
the City and County MSCP subarea plans promotes the long-term 
conservation of this species and its essential habitat within all areas 
covered by the subarea plans under the MSCP.
    The approximate acreage of land that meets the definition of 
critical habitat for Ambrosia pumila within the City of San Diego 
Subarea and conservation status of those lands is summarized in Table 
3. The City of San Diego has a management plan in place for the A. 
pumila occurrence in Mission Trails Regional Park (Dudek 2000), ongoing 
monitoring of that occurrence (City of San Diego 2000, 2001, 2003, 
2006, and 2008b), and ongoing maintenance of the Mission Trails 
Regional Park occurrence, including building and maintaining fencing 
and rerouting or closing trails to protect plants (Dudek 2000, pp. 29-
30). No management plan, management, or monitoring is yet in place for 
the other non-Federal lands covered by the City or County of San Diego 
Subarea Plans that meet the definition of critical habitat for Ambrosia 
pumila.

Table 3--Lands under the City of San Diego Subarea Plan that meet the definition of critical habitat for Ambrosia pumila (including the Multiple-Habitat
                                                                 Planning Area (MHPA)).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                     Within City of San Diego Subarea          Within City of San Diego MHPA        Conserved within City of San Diego
                                 --------------------------------------------------------------------------------                  MHPA*
          Unit/Subunit                                                                                           ---------------------------------------
                                         acres             hectares              acres             hectares              acres             hectares
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unit 5: San Dieguito River        9.0                 3.6                 3.1                 1.3                 0.0                 0.0
 watershed--Lake Hodges
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unit 6: San Diego River           197.5               79.9                151.5               61.3                46.0                18.6
 watershed--Mission Trails
 Regional Park
--------------------------------------------------------------------------------------------------------------------------------------------------------
      Total AreaConsidered for    206.5               83.6                154.6               62.6                46.0                18.6
       Exclusion
--------------------------------------------------------------------------------------------------------------------------------------------------------
\*\Conserved outside of MHPA: 23.7 ac (9.6 ha).
\**\Values in this table may not sum due to rounding.

    The approximate amount of land that meets the definition of 
critical habitat for Ambrosia pumila within the County of San Diego 
Subarea and conservation status of those lands is summarized in Table 
4.

   Table 4--Lands under the County of San Diego Subarea Plan that meet the definition of critical habitat for Ambrosia pumila (including Pre-Approved
                                         Mitigation Areas (PAMA); areas on Federal lands noted in parentheses).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                  Within County of San Diego Subarea (on    Within County of San Diego PAMA (on    Conserved within County of San Diego
                                              Federal lands)                          Federal lands)                    PAMA\*\ (on Federal lands)
          Unit/Subunit           -----------------------------------------------------------------------------------------------------------------------
                                         acres             hectares              acres             hectares              acres             hectares
--------------------------------------------------------------------------------------------------------------------------------------------------------
7A. Jamul Road                    38.9                15.7                20.4                8.2                 13.6                5.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
7B. San Diego National Wildlife   132.5               53.6                116.2               47.0                116.1               47.0
 Refuge                           (116.1)...........  (47.0)............  (116.1)...........  (47.0)............  (116.1)...........  (47.0)
--------------------------------------------------------------------------------------------------------------------------------------------------------
7C. Steele Canyon Bridge          43.7                17.7                30.6                12.4                28.4                11.5
                                  (27.6)............  (11.2)............  (27.6)............  (11.2)............  (27.6)............   (11.2)
--------------------------------------------------------------------------------------------------------------------------------------------------------
      Totals:                     215.2               87.1                167.1               67.6                158.1               64.0
                                  (143.7)...........  (58.1)............  (143.7)...........  (58.1)............  (143.7)...........   (58.1)
--------------------------------------------------------------------------------------------------------------------------------------------------------
      Total Area Considered for   71.5                29.0                23.4                9.5                 14.4                5.9
       Exclusion (non-Federal
       lands only)
--------------------------------------------------------------------------------------------------------------------------------------------------------
\*\Conserved outside of PAMA: 0.1 ac (0.0 ha)
\**\Values in this table may not sum due to rounding.


[[Page 44257]]

    Approximately 51.9 ac (21.0 ha), or 25 percent of non-Federal lands 
under the City of San Diego's Subarea Plan that meet the definition of 
critical habitat, are outside the Multi-Habitat Planning Area; 
approximately 48.1 ac (23.2 ha), or 67.3 percent of non-Federal lands 
under the County of San Diego's Subarea Plan that meet the definition 
of critical habitat, are outside the Pre-Approved Mitigation Areas. 
Consistent with the narrow endemic species requirements of the MSCP, 
the lands outside the Pre-Approved Mitigation Areas and Multi-Habitat 
Planning Area will be surveyed for Ambrosia pumila prior to any 
development occurring on these lands, and any occurrences of A. pumila 
discovered must be protected in accordance with those requirements. 
Additionally, as stated above, preservation and management will be 
provided for occurrences within the preserve areas of these subarea 
plans.
    In summary, we are considering exclusion of 278 ac (113 ha) of non-
Federal lands that meet the definition of critical habitat for Ambrosia 
pumila within the City and County of San Diego Subarea Plans under 
section 4(b)(2) of the Act. There are an additional 143.7 ac (58.1 ha) 
of Federal land at the San Diego National Wildlife Refuge included in 
Subunits 7B and 7C that are within the County of San Diego's subarea 
plan that meet the definition of critical habitat, but because these 
lands are federally owned we are not considering them for exclusion. 
The 2002 final listing rule for A. pumila identified the following 
primary threats for this species: habitat destruction and fragmentation 
from urban development and development of recreational activities; 
highway and utility corridor construction, highway expansion, and 
maintenance of these corridors; trampling and soil compaction caused by 
hikers, horses, and vehicles; fire suppression practices; competition 
from nonnative plant species; and stochastic events such as fire or 
drought (67 FR 44372; July 2, 2002). The implementation of the City and 
County of San Diego MSCP subarea plans helps to address these threats 
through a regional planning effort rather than through a project-by-
project approach, and outlines species-specific objectives and criteria 
for the conservation of A. pumila. We will analyze the benefits of 
inclusion and exclusion of this area from critical habitat under 
section 4(b)(2) of the Act. We encourage any public comment in relation 
to our consideration of the areas discussed above for inclusion or 
exclusion.
Economic Analysis
    Section 4(b)(2) of the Act allows the Secretary to exclude areas 
from critical habitat for economic reasons if the Secretary determines 
that the benefits of such exclusion exceed the benefits of designating 
the area as critical habitat. However, this exclusion cannot occur if 
it will result in the extinction of the species concerned.
    In compliance with section 4(b)(2) of the Act, we are preparing an 
analysis of the economic impacts of proposing critical habitat 
designation and related factors for Ambrosia pumila, to evaluate the 
potential economic impact of the designation. This economic analysis 
also will be used to determine compliance with the Regulatory 
Flexibility Act, the Small Business Regulatory Enforcement Fairness 
Act, E.O. 12630 (Takings), and E.O. 13211 (Energy Supply, Distribution, 
or Use).
    We will announce the availability of the draft economic analysis as 
soon as it is completed, at which time we will seek public review and 
comment. At that time, copies of the draft economic analysis will be 
available for downloading from the Internet at http://www.regulations.gov, or by contacting the Carlsbad Fish and Wildlife 
Office directly (see FOR FURTHER INFORMATION CONTACT section). Based on 
public comment on that document, and our evaluation of the relative 
benefits of inclusions and exclusion, areas may be excluded from 
critical habitat by the Secretary under the provisions of section 
4(b)(2) of the Act in the final rule, as provided for in the Act and in 
our implementing regulations at 50 CFR 242.19.
Peer Review
    In accordance with our joint policy published in the Federal 
Register on July 1, 1994 (59 FR 34270), we are soliciting the expert 
opinions of at least three appropriate independent specialists 
regarding this proposed rule. The purpose of peer review is to ensure 
that our critical habitat designation is based on scientifically sound 
data, assumptions, and analyses. We have invited these peer reviewers 
to comment during this public comment period on our specific 
assumptions and conclusions in this proposed designation of critical 
habitat. We will consider all comments and information we receive 
during this comment period on this proposed rule during our preparation 
of a final determination. Accordingly, our final decision may differ 
from this proposal.
Public Hearings
    Section 4(b)(5) of the Act provides for one or more public hearings 
on this proposal, if we receive any requests for hearings. We must 
receive your request for a public hearing within 45 days after the date 
of this Federal Register publication. Send your request to Jim Bartel, 
Field Supervisor of the Carlsbad Fish and Wildlife Office (see FOR 
FURTHER INFORMATION CONTACT section). We will schedule public hearings 
on this proposal, if any are requested, and announce the dates, times, 
and places of those hearings, as well as how to obtain reasonable 
accommodations, in the Federal Register and local newspapers at least 
15 days before the first hearing.
Required Determinations

Regulatory Planning and Review--Executive Order 12866

    The Office of Management and Budget (OMB) has determined that this 
rule is not significant under Executive Order (E.O.) 12866. OMB bases 
its determination upon the following four criteria:
    (1) Whether the rule will have an annual effect of $100 million or 
more on the economy or adversely affect an economic sector, 
productivity, jobs, the environment, or other units of the government.
    (2) Whether the rule will create inconsistencies with other Federal 
agencies' actions.
    (3) Whether the rule will materially affect entitlements, grants, 
user fees, loan programs, or the rights and obligations of their 
recipients.
    (4) Whether the rule raises novel legal or policy issues.

Regulatory Flexibility Act (5 U.S.C. 601 et seq.)

    Under the Regulatory Flexibility Act (RFA; 5 U.S.C. 601 et seq., as 
amended by the Small Business Regulatory Enforcement Fairness Act 
(SBREFA) of 1996), whenever an agency must publish a notice of 
rulemaking for any proposed or final rule, it must prepare and make 
available for public comment a regulatory flexibility analysis that 
describes the effect of the rule on small entities (i.e., small 
businesses, small organizations, and small government jurisdictions). 
However, no regulatory flexibility analysis is required if the head of 
an agency certifies the rule will not have a significant economic 
impact on a substantial number of small entities. The SBREFA amended 
the RFA to require Federal agencies to provide a statement of factual 
basis for certifying that the rule will not have a significant

[[Page 44258]]

economic impact on a substantial number of small entities.
    At this time, we lack the available economic information necessary 
for the areas being proposed in this revision to provide an adequate 
factual basis for the required RFA finding. Therefore, we defer the RFA 
finding until completion of the draft economic analysis prepared under 
section 4(b)(2) of the Act and E.O. 12866. The draft economic analysis 
will provide the required factual basis for the RFA finding. Upon 
completion of the draft economic analysis, we will announce its 
availability in the Federal Register and reopen the public comment 
period for the proposed designation. We will include with this 
announcement, as appropriate, an initial regulatory flexibility 
analysis or a certification that the rule will not have a significant 
economic impact on a substantial number of small entities accompanied 
by the factual basis for that determination. We concluded that 
deferring the RFA finding until completion of the draft economic 
analysis is necessary to meet the purposes and requirements of the RFA. 
Deferring the RFA finding in this manner will ensure that we make a 
sufficiently informed determination based on adequate economic 
information and provide the necessary opportunity for public comment.

Unfunded Mandates Reform Act (2 U.S.C. 1501 et seq.)

    In accordance with the Unfunded Mandates Reform Act, we make the 
following findings:
    1. This rule will not produce a Federal mandate. In general, a 
Federal mandate is a provision in legislation, statute, or regulation 
that would impose an enforceable duty upon State, local, or Tribal 
governments, or the private sector, and includes both ``Federal 
intergovernmental mandates'' and ``Federal private sector mandates.'' 
These terms are defined in 2 U.S.C. 658(5)-(7). ``Federal 
intergovernmental mandate'' includes a regulation that ``would impose 
an enforceable duty upon State, local, or [T]ribal governments'' with 
two exceptions. It excludes ``a condition of Federal assistance.'' It 
also excludes ``a duty arising from participation in a voluntary 
Federal program,'' unless the regulation ``relates to a then-existing 
Federal program under which $500,000,000 or more is provided annually 
to State, local, and [T]ribal governments under entitlement 
authority,'' if the provision would ``increase the stringency of 
conditions of assistance'' or ``place caps upon, or otherwise decrease, 
the Federal Government's responsibility to provide funding,'' and the 
State, local, or Tribal governments ``lack authority'' to adjust 
accordingly. At the time of enactment, these entitlement programs were: 
Medicaid; AFDC work programs; Child Nutrition; Food Stamps; Social 
Services Block Grants; Vocational Rehabilitation State Grants; Foster 
Care, Adoption Assistance, and Independent Living; Family Support 
Welfare Services; and Child Support Enforcement. ``Federal private 
sector mandate'' includes a regulation that ``would impose an 
enforceable duty upon the private sector, except (i) a condition of 
Federal assistance or (ii) a duty arising from participation in a 
voluntary Federal program.''
    The designation of critical habitat does not impose a legally 
binding duty on non-Federal Government entities or private parties. 
Under the Act, the only regulatory effect is that Federal agencies must 
ensure that their actions do not destroy or adversely modify critical 
habitat under section 7. While non-Federal entities that receive 
Federal funding, assistance, permits, or otherwise require approval or 
authorization from a Federal agency for an action, may be indirectly 
impacted by the designation of critical habitat, the legally binding 
duty to avoid destruction or adverse modification of critical habitat 
rests squarely on the Federal agency. Furthermore, to the extent that 
non-Federal entities are indirectly impacted because they receive 
Federal assistance or participate in a voluntary Federal aid program, 
the Unfunded Mandates Reform Act would not apply, nor would critical 
habitat shift the costs of the large entitlement programs listed above 
onto State governments.
    2. We do not expect this rule to significantly or uniquely affect 
small governments. Small governments will be affected only to the 
extent that any programs having Federal funds, permits, or other 
authorized activities must ensure that their actions will not adversely 
affect the critical habitat. Therefore, a Small Government Agency Plan 
is not required. However, as we conduct our economic analysis for the 
rule, we will further evaluate this issue and revise this assessment if 
appropriate.

Takings--Executive Order 12630

    In accordance with E.O. 12630 (Government Actions and Interference 
with Constitutionally Protected Private Property Rights), we have 
analyzed the potential takings implications of designating critical 
habitat for Ambrosia pumila in a takings implications assessment. The 
takings implications assessment concludes that this designation of 
critical habitat for A. pumila does not pose significant takings 
implications for lands within or affected by the designation.

Federalism--Executive Order 13132

    In accordance with E.O. 13132 (Federalism), this proposed rule does 
not have significant Federalism effects. A Federalism assessment is not 
required. In keeping with Department of the Interior and Department of 
Commerce policy, we requested information from, and coordinated 
development of, this proposed critical habitat designation with 
appropriate State resource agencies in California. The designation may 
have some benefit to these governments because the areas that contain 
the features essential to the conservation of the species are more 
clearly defined, and the PCEs of the habitat necessary to the 
conservation of the species are specifically identified. This 
information does not alter where and what federally sponsored 
activities may occur. However, it may assist these local governments in 
long-range planning (rather than having them wait for case-by-case 
section 7 consultations to occur).
    Where State and local governments require approval or authorization 
from a Federal agency for actions that may affect critical habitat, 
consultation under section 7(a)(2) would be required. While non-Federal 
entities that receive Federal funding, assistance, or permits, or that 
otherwise require approval or authorization from a Federal agency for 
an action, may be indirectly impacted by the designation of critical 
habitat, the legally binding duty to avoid destruction or adverse 
modification of critical habitat rests squarely on the Federal agency.

Civil Justice Reform--Executive Order 12988

    In accordance with Executive Order 12988 (Civil Justice Reform), it 
has been determined that the rule does not unduly burden the judicial 
system and meets the requirements of sections 3(a) and 3(b)(2) of the 
Order. We have proposed designation of critical habitat in accordance 
with the provisions of the Endangered Species Act. This proposed rule 
uses standard property descriptions and identifies the PCEs within the 
designated areas to assist the public in understanding the habitat 
needs of Ambrosia pumila.

Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.)

    This rule does not contain any new collections of information that 
require

[[Page 44259]]

approval by OMB under the Paperwork Reduction Act of 1995. This rule 
will not impose recordkeeping or reporting requirements on State or 
local governments, individuals, businesses, or organizations. An agency 
may not conduct or sponsor, and a person is not required to respond to, 
a collection of information unless it displays a currently valid OMB 
control number.

National Environmental Policy Act (NEPA) (42 U.S.C. 4321 et. seq.)

    It is our position that, outside the jurisdiction of the Circuit 
Court of the United States for the Tenth Circuit, we do not need to 
prepare environmental analyses as defined by NEPA in connection with 
designating critical habitat under the Endangered Species Act. We 
published a notice outlining our reasons for this determination in the 
Federal Register on October 25, 1983 (48 FR 49244). This assertion was 
upheld by the Circuit Court of the United States for the Ninth Circuit 
(Douglas County v. Babbitt, 48 F.3d 1495 (9th Cir. 1995), cert. denied 
516 U.S. 1042 (1996)).

Clarity of the Rule

    We are required by Executive Orders 12866 and 12988 and by the 
Presidential Memorandum of June 1, 1998, to write all rules in plain 
language. This means that each rule we publish must:
    (1) Be logically organized;
    (2) Use the active voice to address readers directly;
    (3) Use clear language rather than jargon;
    (4) Be divided into short sections and sentences; and
    (5) Use lists and tables wherever possible.
    If you feel that we have not met these requirements, send us 
comments by one of the methods listed in the ADDRESSES section. To 
better help us revise the rule, your comments should be as specific as 
possible. For example, you should tell us the numbers of the sections 
or paragraphs that are unclearly written, which sections or sentences 
are too long, the sections where you feel lists or tables would be 
useful, etc.

Government-to-Government Relationship with Tribes

    In accordance with the President's memorandum of April 29, 1994, 
Government-to-Government Relations with Native American Tribal 
Governments (59 FR 22951), E.O. 13175, and the Department of the 
Interior's manual at 512 DM 2, we readily acknowledge our 
responsibility to communicate meaningfully with recognized Federal 
Tribes on a government-to-government basis. In accordance with 
Secretarial Order 3206 of June 5, 1997 (American Indian Tribal Rights, 
Federal-Tribal Trust Responsibilities, and the Endangered Species Act), 
we readily acknowledge our responsibilities to work directly with 
Tribes in developing programs for healthy ecosystems, to acknowledge 
that Tribal lands are not subject to the same controls as Federal 
public lands, to remain sensitive to Indian culture, and to make 
information available to Tribes.
    We determined there are no Tribal lands occupied by Ambrosia pumila 
at the time of listing that contain the features essential for the 
conservation of Ambrosia pumila, nor are there any other Tribal lands 
that are essential for the conservation of this species. Therefore, 
designation of critical habitat for A. pumila is not being proposed on 
Tribal lands. We will continue to coordinate with Tribal governments as 
appropriate during the designation process.

Energy Supply, Distribution, or Use--Executive Order 13211

    Executive Order 13211, ``Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use'' requires 
agencies to prepare Statements of Energy Effects when undertaking 
certain actions. Based on an analysis conducted for the preparation of 
this proposal, we determined that this proposed rule to designate 
critical habitat for Ambrosia pumila is not expected to significantly 
affect energy supplies, distribution, or use. Therefore, this action is 
not a significant energy action, and no Statement of Energy Effects is 
required. However, we will further evaluate this issue as we conduct 
our economic analysis, and review and revise this assessment as 
warranted.

References Cited

    A complete list of all references cited in this rulemaking is 
available on http://wwww.regulations.gov and upon request from the 
Field Supervisor, Carlsbad Fish and Wildlife Office (see FOR FURTHER 
INFORMATION CONTACT section).

Author(s)

    The primary author of this notice is the staff from the Carlsbad 
Fish and Wildlife Office (see FOR FURTHER INFORMATION CONTACT section).

List of Subjects in 50 CFR Part 17

    Endangered and threatened species, Exports, Imports, Reporting and 
recordkeeping requirements, Transportation.

Proposed Regulation Promulgation

    Accordingly, we propose to amend part 17, subchapter B of chapter 
I, title 50 of the Code of Federal Regulations, as set forth below:

PART 17--[AMENDED]

    1. The authority citation for part 17 continues to read as follows:

    Authority:  16 U.S.C. 1361-1407; 16 U.S.C. 1531-1544; 16 U.S.C. 
4201-4245; Pub. L. 99-625, 100 Stat. 3500; unless otherwise noted.

    2. In Sec.  17.12(h), revise the entry for ``Ambrosia pumila'' 
under ``FLOWERING PLANTS'' to read as follows:


Sec.  17.12  Endangered and threatened plants.

* * * * *
    (h) * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------
                    Species
------------------------------------------------  Historic range        Family            Status         When listed        Critical      Special rules
       Scientific name            Common name                                                                               habitat
--------------------------------------------------------------------------------------------------------------------------------------------------------
FLOWERING PLANTS                                                                                                                         ...............
--------------------------------------------------------------------------------------------------------------------------------------------------------
* * * * * * *                                                                                                                            ...............
--------------------------------------------------------------------------------------------------------------------------------------------------------
Ambrosia pumila                San Diego         U.S.A. (CA),      Asteraceae        E                 727              17.96(a)         NA
                                ambrosia          Mexico
--------------------------------------------------------------------------------------------------------------------------------------------------------
* * * * * * *                                                                                                                            ...............
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 44260]]

    3. In Sec.  17.96(a), add an entry for ``Ambrosia pumila (San Diego 
ambrosia),'' in alphabetical order under family Asteraceae, to read as 
follows:


Sec.  17.96  Critical habitat--plants.

    (a) Flowering plants.
* * * * *
Family Asteraceae: Ambrosia pumila (San Diego ambrosia)
    (1) Critical habitat units are depicted for Riverside and San Diego 
Counties, California, on the maps below.
    (2) Within these areas, the primary constituent elements (PCEs) of 
critical habitat for Ambrosia pumila are:
    (i) Sandy loam or clay soils (regardless of disturbance status), 
including (but not limited to) the Placentia (sandy loam), Diablo 
(clay), and Ramona (sandy loam) soil series that occur on or near (but 
not directly adjacent to) a river, creek, or other drainage, or within 
the watershed of a vernal pool, and that occur on an upper terrace 
(flat or gently sloping areas of 0 to 42 percent slopes are typical for 
terraces on which A. pumila occurrences are found).
    (ii) Grassland or ruderal habitat types (disturbed communities 
containing a mixture of native and nonnative grasses and forbs) or 
openings within coastal sage scrub, on the soil types and topography 
described in the PCE set forth in paragraph (2)(i) of this entry, that 
provide adequate sunlight and airflow for population growth and 
reproduction.
    (3) Critical habitat does not include manmade structures existing 
on the effective date of this rule, such as buildings, aqueducts, 
airports, and roads, and the land on which such structures are located, 
and not containing one or more of the PCEs.
    (4) Critical habitat map units. Data layers defining map units were 
created using a base of U.S. Geological Survey 7.5' quadrangle maps. 
Critical habitat units were then mapped using Universal Transverse 
Mercator (UTM) zone 11, North American Datum (NAD) 1983 coordinates. 
These coordinates establish the vertices and endpoints of the 
boundaries of the units and subunits.
    (5) Note: Index Map of critical habitat for Ambrosia pumila (San 
Diego ambrosia), Riverside and San Diego Counties, California, follows:
BILLING CODE 4310-55-S

[[Page 44261]]

[GRAPHIC] [TIFF OMITTED] TP27AU09.199

    (6) Unit 1, Riverside County, California.
    (i) [Reserved for textual description of units.]
    (ii) Note: Map of Unit 1, Critical Habitat for Ambrosia pumila (San 
Diego ambrosia), Riverside County, California, follows:

[[Page 44262]]

[GRAPHIC] [TIFF OMITTED] TP27AU09.200

    (7) Units 2 and 3, Riverside County, California.
    (i) [Reserved for textual description of units.]
    (ii) Note: Map of Units 2 and 3, Critical Habitat for Ambrosia 
pumila (San Diego ambrosia), Riverside County, California, follows:

[[Page 44263]]

[GRAPHIC] [TIFF OMITTED] TP27AU09.201

    (8) Unit 4, Subunits 4A, 4B, and 4C, San Diego County, California.
    (i) [Reserved for textual description of unit.]
    (ii) Note: Map of Unit 4, Critical Habitat for Ambrosia pumila (San 
Diego ambrosia), San Diego County, California, follows:

[[Page 44264]]

[GRAPHIC] [TIFF OMITTED] TP27AU09.202

    (9) Unit 5, San Diego County, California.
    (i) [Reserved for textual description of units.]
    (ii) Note: Map of Unit 5, Critical Habitat for Ambrosia pumila (San 
Diego ambrosia), San Diego County, California, follows:

[[Page 44265]]

[GRAPHIC] [TIFF OMITTED] TP27AU09.203

    (10) Unit 6, San Diego County, California.
    (i) [Reserved for textual description of units.]
    (ii) Note: Map of Unit 6, Critical Habitat for Ambrosia pumila (San 
Diego ambrosia), San Diego County, California, follows:

[[Page 44266]]

[GRAPHIC] [TIFF OMITTED] TP27AU09.204

    (11) Unit 7, Subunits 7A, 7B, and 7C, San Diego County, California.
    (i) [Reserved for textual description of units.]
    (ii) Note: Map of Unit 7, Critical Habitat for Ambrosia pumila (San 
Diego ambrosia), San Diego County, California, follows:

[[Page 44267]]

[GRAPHIC] [TIFF OMITTED] TP27AU09.205


    Dated: August 14, 2009
Will Shafroth,
Acting Assistant Secretary for Fish and Wildlife and Parks.
[FR Doc. E9-20499 Filed 8-26-09; 8:45 am]
BILLING CODE 4310-55-C