Endangered and Threatened Wildlife and Plants; Proposed Designation of Critical Habitat for Piperia Yadonii, 61546-61578 [06-8600]

Agencies

• DEPARTMENT OF THE INTERIOR
• Fish and Wildlife Service

[Federal Register Volume 71, Number 201 (Wednesday, October 18, 2006)]
[Proposed Rules]
[Pages 61546-61578]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 06-8600]



[[Page 61545]]

-----------------------------------------------------------------------

Part II





Department of the Interior





-----------------------------------------------------------------------



Fish and Wildlife Service



-----------------------------------------------------------------------



50 CFR Part 17



 Endangered and Threatened Wildlife and Plants; Proposed Designation of 
Critical Habitat for Piperia yadonii (Yadon's piperia); Proposed Rule

Federal Register / Vol. 71, No. 201 / Wednesday, October 18, 2006 / 
Proposed Rules

[[Page 61546]]


-----------------------------------------------------------------------

DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

RIN 1018-AU34


Endangered and Threatened Wildlife and Plants; Proposed 
Designation of Critical Habitat for Piperia Yadonii (Yadon's Piperia)

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

-----------------------------------------------------------------------

SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to 
designate critical habitat for the endangered Piperia yadonii (Yadon's 
piperia) pursuant to the Endangered Species Act of 1973, as amended 
(Act). In total, approximately 2,306 acres (ac) (930 hectares (ha)) 
fall within the boundaries of the proposed critical habitat 
designation. The proposed critical habitat is located in Monterey 
County, California.

DATES: We will accept comments from all interested parties until 
December 18, 2006. We must receive requests for public hearings, in 
writing, at the address shown in the ADDRESSES section by December 4, 
2006.

ADDRESSES: If you wish to comment, you may submit your comments and 
materials concerning this proposal by any one of several methods:
    1. You may submit written comments and information to the Field 
Supervisor, U.S. Fish and Wildlife Service, Ventura Fish and Wildlife 
Office (VFWO), 2493 Portola Road, Suite B, Ventura, California 93003.
    2. You may hand-deliver written comments to our Ventura Fish and 
Wildlife Office, at the above address.
    3. You may send comments by electronic mail (e-mail) to 
fw8piya@fws.gov. Please see the Public Comments Solicited section below 
for file format and other information about electronic filing.
    4. You may fax your comments to (805) 644-3958.
    5. You may go to the Federal eRulemaking Portal: https://
www.regulations.gov.
    Comments and materials received, as well as supporting 
documentation used in the preparation of this proposed rule, will be 
available for public inspection, by appointment, during normal business 
hours at our VFWO, at the above address (telephone (805) 644-1766).

FOR FURTHER INFORMATION CONTACT: Diane Noda, Field Supervisor, VFWO, at 
the above address (telephone (805) 644-1766, ext. 319; facsimile (805) 
644-3958).

SUPPLEMENTARY INFORMATION:

Public Comments Solicited

    We intend that any final action resulting from this proposal will 
be as accurate and as effective as possible. Therefore, comments or 
suggestions from the public, other concerned governmental agencies, the 
scientific community, industry, or any other interested party 
concerning this proposed rule are hereby solicited. Comments 
particularly are sought concerning:
    (1) The reasons any habitat should or should not be determined to 
be critical habitat as provided by section 4 of the Act, including 
whether the benefit of designation will outweigh any threats to the 
species due to designation;
    (2) Specific information on the amount and distribution of Piperia 
yadonii habitat, what areas should be included in the designations that 
were occupied at the time of listing and contain the features that are 
essential for the conservation of the species and why, and what areas 
that were not occupied at the listing are essential to the conservation 
of the species and why;
    (3) Our mapping methodology and criteria used for determining 
critical habitat as well as any additional information on features 
essential for the conservation of the species;
    (4) Land use designations and current or planned activities in the 
subject areas and their possible impacts on proposed critical habitat;
    (5) The existence of conservation agreements, management plans, or 
strategies that should be considered in determining whether to exclude 
lands from the designation. If the Secretary determines the benefits of 
excluding lands outweigh the benefits of including them, lands will be 
excluded from the final critical habitat designation;
    (6) Any foreseeable economic, national security, or other potential 
impacts resulting from the proposed designation and, in particular, any 
impacts on small entities; and
    (7) Whether our approach to designating critical habitat could be 
improved or modified in any way to provide for greater public 
participation and understanding, or to assist us in accommodating 
public concerns and comments.
    If you wish to comment, you may submit your comments and materials 
concerning this proposal by any one of several methods (see ADDRESSES 
section). Please submit electronic comments to fw8piya@fws.gov in ASCII 
file format and avoid the use of special characters or any form of 
encryption. Please also include ``Attn: Yadon's piperia'' in your e-
mail subject header and your name and return address in the body of 
your message. If you do not receive a confirmation from the system that 
we have received your e-mail message, contact us directly by calling 
our VFWO at phone number (805) 644-1766, ext. 333. Please note that the 
e-mail address fw8piya@fws.gov will be closed out at the termination of 
the public comment period.
    Our practice is to make comments, including names and home 
addresses of respondents, available for public review during regular 
business hours. Individual respondents may request that we withhold 
their names and/or home addresses, etc. but if you wish us to consider 
withholding this information you must state this prominently at the 
beginning of your comments. In addition, you must present a rationale 
for withholding this information. This rational must demonstrate that 
disclosure would constitute a clearly unwarranted invasion of privacy. 
Unsupported assertions will not meet this burden. In the absence of 
exceptional, documentable circumstances, this information will be 
released. We will always make submissions from organizations or 
businesses, and from individuals identifying themselves as 
representatives of or officials of organizations or businesses, 
available for public inspection in their entirety. Comments and 
materials received will be available for public inspection, by 
appointment, during normal business hours at the U.S. Fish and Wildlife 
Service Office at the above address.

Role of Critical Habitat in Actual Practice of Administering and 
Implementing the Act

    Attention to and protection of habitat is paramount to successful 
conservation actions. The role that designation of critical habitat 
plays in protecting habitat of listed species, however, is often 
misunderstood. As discussed in more detail below in the discussion of 
exclusions under section 4(b)(2) of the Act, there are significant 
limitations on the regulatory effect of designation under section 
7(a)(2) of the Act. In brief, (1) designation provides additional 
protection to habitat only where there is a federal nexus; (2) the 
protection is relevant only when, in the absence of designation, 
destruction or adverse modification of the critical habitat would in 
fact take place (in other words, other statutory or regulatory 
protections, policies, or other factors relevant to

[[Page 61547]]

agency decision-making would not prevent the destruction or adverse 
modification); and (3) designation of critical habitat triggers the 
prohibition of destruction or adverse modification of that habitat, but 
it does not require specific actions to restore or improve habitat.
    Currently, only 475 species, or 36 percent of the 1,311 listed 
species in the U.S. under the jurisdiction of the Service, have 
designated critical habitat. We address the habitat needs of all 1,311 
listed species through conservation mechanisms such as listing, section 
7 consultations, the section 4 recovery planning process, the section 9 
protective prohibitions of unauthorized take, section 6 funding to the 
States, the section 10 incidental take permit process, and cooperative, 
nonregulatory efforts with private landowners. The Service believes 
that it is these measures that may make the difference between 
extinction and survival for many species.
    In considering exclusions of areas proposed for designation, we 
evaluated the benefits of designation in light of Gifford Pinchot Task 
Force v. U.S. Fish and Wildlife Service, 378 F.3d 1059 (9th Cir 2004) 
(hereinafter Gifford Pinchot). In that case, the Ninth Circuit 
invalidated the Service's regulation defining ``destruction or adverse 
modification of critical habitat.'' In response, on December 9, 2004, 
the Director issued guidance to be considered in making section 7 
adverse modification determinations. This proposed critical habitat 
designation does not use the invalidated regulation in our 
consideration of the benefits of including areas in this proposed 
designation. The Service will carefully manage future consultations 
that analyze impacts to designated critical habitat, particularly those 
that appear to be resulting in an adverse modification determination. 
Such consultations will be reviewed by the Regional Office prior to 
finalizing to ensure that an adequate analysis has been conducted that 
is informed by the Director's guidance.
    On the other hand, to the extent that designation of critical 
habitat provides protection, that protection can come at significant 
social and economic cost. In addition, the mere administrative process 
of designation of critical habitat is expensive, time-consuming, and 
controversial. The current statutory framework of critical habitat, 
combined with past judicial interpretations of the statute, make 
critical habitat the subject of excessive litigation. As a result, 
critical habitat designations are driven by litigation and courts 
rather than biology, and made at a time and under a timeframe that 
limits our ability to obtain and evaluate the scientific and other 
information required to make the designation most meaningful.
    In light of these circumstances, the Service believes that 
additional agency discretion would allow our focus to return to those 
actions that provide the greatest benefit to the species most in need 
of protection.

Procedural and Resource Difficulties in Designating Critical Habitat

    We have been inundated with lawsuits for our failure to designate 
critical habitat, and we face a growing number of lawsuits challenging 
critical habitat determinations once they are made. These lawsuits have 
subjected the Service to an increasing series of court orders and 
court-approved settlement agreements, which complying with now consumes 
nearly the entire listing program budget. This leaves the Service with 
little ability to prioritize its activities to direct scarce listing 
resources to the listing program actions with the most biologically 
urgent species conservation needs.
    The consequence of the critical habitat litigation activity is that 
limited listing funds are used to defend active lawsuits, to respond to 
Notices of Intent (NOIs) to sue relative to critical habitat, and to 
comply with the growing number of adverse court orders. As a result, 
listing petition responses, the Service's own proposals to list 
critically imperiled species, and final listing determinations on 
existing proposals are all significantly delayed.
    The accelerated schedules of court-ordered designations have left 
the Service with limited ability to provide for public participation or 
to ensure a defect-free rulemaking process before making decisions on 
listing and critical habitat proposals, due to the risks associated 
with noncompliance with judicially imposed deadlines. This in turn 
fosters a second round of litigation in which those who fear adverse 
impacts from critical habitat designations challenge those 
designations. The cycle of litigation appears endless, and is very 
expensive, thus diverting resources from conservation actions that may 
provide relatively more benefit to imperiled species.
    The costs resulting from the designation include legal costs, the 
cost of preparation and publication of the designation, the analysis of 
the economic effects and the cost of requesting and responding to 
public comment, and in some cases the costs of compliance with the 
National Environmental Policy Act (NEPA). These costs, which are not 
required for many other conservation actions, directly reduce the funds 
available for direct and tangible conservation actions.

Background

    It is our intent to discuss only those topics directly relevant to 
the designation of critical habitat in this proposed rule and that 
clarify the species description and biology provided in the final 
listing rule. For more information on Piperia yadonii, refer to the 
final listing rule published in the Federal Register on August 12, 1998 
(63 FR 43100).
    Piperia yadonii is a perennial herb in the Orchidaceae (Orchid 
family), which produces one or two basal strap-shaped leaves that grow 
from an underground tuber (the storage organ which persists when the 
species is not present aboveground). P. yadonii leaves emerge in late 
fall or winter, after the soils are saturated by the onset of 
California's wet season rains. Small tubers produce a single leaf, 
which may resemble a grass blade when small (Graff 2006, p. 12). Larger 
tubers produce two basal leaves, often 4 to 6 inches (10 to 15 
centimeters (cm)) long and about 1 inch (2 to 3 cm) wide, at maturity. 
Emergence of the single flowering stalk above ground typically begins 
in April (Doak and Graff 2001, p. 2). As the inflorescence grows to its 
full height, usually 8 to 20 inches (20 to 50 cm) tall, the plant's 
basal leaves wither (Morgan and Ackerman 1990, p. 209). Flowering 
occurs in the summer, typically from June to August. The average number 
of flowers recorded on inflorescences in a recent study was 56 (Doak 
and Graff 2001, p. 3). Similar to other orchid species, only a small 
proportion of the plants that produce leaves in a given year will 
produce an inflorescence. Recorded flowering rates for P. yadonii 
plants that have one or more leaves range from 0.4 to 22 percent, and 
vary by site and year (Allen 1996, unpaginated; Doak and Graff 2001, 
pp. 14-15; EcoSystems West Consulting Group (Ecosystems West) 2006, pp. 
71-72). Like other orchid species, the ability to produce flowering 
stalks may be a function of tuber size (indicative of energy reserves), 
rather than age (Wells 1981, pp. 291-293; Rasmussen 1995, pp. 197-200). 
Consequently, an individual that flowers in one year may not be able to 
flower in subsequent years.
    Piperia yadonii requires pollinators to produce seeds. Flowers that 
are not visited by pollinators do not produce seed. Flowers that are 
visited by pollinators and receive self pollen from other flowers on 
the same plant will produce seeds, although they produce

[[Page 61548]]

significantly fewer seeds than result from cross pollinations between 
plants. This is an expression of inbreeding depression in seed set 
(Doak and Graff 2001, pp. 12-15). The presence of inbreeding depression 
in later stages, such as seed germination and establishment, has not 
been studied in P. yadonii. In Monterey pine (Pinus radiata) forest 
habitats, the most abundant insects that have been collected and 
observed visiting P. yadonii flowers are nocturnal short-tongued moths 
in the families Pyralidae, Geometridae, Noctuidae, and Pterophoridae. 
Six moth species in these families had Piperia yadonii pollen attached 
to their bodies, confirming that they transport, and can potentially 
transfer, pollen between flowers (Doak and Graff 2001, pp. 8-25). 
Nocturnal moths are a commonly reported pollinator of other Piperia 
species (Ackerman 1977a, pp. 256-257). None of the nocturnal moth 
visitors are thought to be rare. Of the moths carrying P. yadonii 
pollen, two species are known to be generalist feeders in the larval 
stage and are found on a variety of native plants and agricultural 
crops. Three species have more exclusive larval feeding habits, having 
been recorded on native shrubs (e.g., coyote brush (Baccharis 
pilularis); California lilac (Ceanothus spp.)) and members of the mint 
family (Lamiaceae) (Doak and Graff 2001, pp. 8-25; Graff 2005). A 
bumble bee (Bombus sp.) and one mosquito (species unknown) were also 
collected among P. yadonii flowering plants and had pollen attached to 
their bodies (Doak and Graff 2001, pp. 8-25; Graff 2005). Bumblebees 
have been identified as a diurnal visitor by other observers, as well 
(Yadon 2001, unpaginated). In maritime chaparral, rates of insect 
visitation to Piperia yadonii populations were so low that no 
pollinator data was collected (Doak and Graff 2001, pp. 8-37). 
Nonnative earwigs (Forficula auricularia) have been documented to 
consume substantial amounts of pollen from P. yadonii flowers in 
several populations found in Monterey pine forest (Doak and Graff 2001, 
p. 9). It is not known if this pollen theft results in depressed seed 
set.
    Each successfully maturing seed capsule of Piperia yadonii can 
contain hundreds of seeds, so a single plant can produce several 
thousand seeds (Doak and Graff 2001, pp. 13-31). Orchid seeds are 
typically minute, with a large volume of air compared to the size of 
the embryo. These attributes make the seeds particularly buoyant, 
promoting wind dispersal (Healey et al. 1980, pp. 508, 516; Rasmussen 
1995, pp. 7-10). The distance seeds routinely travel is unknown. In a 
study of an epiphytic (tree growing) orchid, most seeds landed within 
meters of the plant (Ackerman et al. 1996, pp. 195-197). However, 
others have noted that orchids may be one of the earliest colonizers of 
new island habitats hundreds of kilometers from other land masses, 
suggesting that occasional very long distance dispersal can occur 
(Healy et al. 1980, p. 516). Data on many terrestrial orchids indicates 
low genetic differentiation between populations, suggesting that either 
seeds or pollen are moving between populations (Ackerman 1997b).
    In general, orchid seeds lack a sufficient internal food source to 
sustain a germinating seedling. Instead, their nutritional needs are 
fulfilled by an association with a soil fungus (a mycorrhizal 
association) (Hadley 1982, pp. 96-101). Nothing specific has been 
published on the mycorrhizal fungal symbionts of Piperia yadonii, nor 
their distribution in the forest and maritime chaparral soils where 
this orchid grows. In other temperate North American orchid species, 
the primary fungal associates are described as belonging to the genus 
Rhizoctonia or being Rhizoctonia-like fungi (Hadley 1982, pp. 96-99; 
Hadley and Pegg 1989, pp. 61-63). The specificity of the association 
between orchids and their mycorrhizal fungi is a field of active study 
(e.g., Otero et al. 2002, pp. 1852-1858). No broad consensus is 
apparent on whether or not the distributions of temperate North 
American orchids might be limited by their dependence on specific 
fungal symbionts. Once the mycorrhizal association between the orchid 
seed and its fungal partner is established, the orchid tuber continues 
to develop underground. If not established, orchid seeds typically fail 
to germinate or seedlings die at an early subterranean phase of 
development (Rasmussen and Whigham 1998, pp. 61-63). The length of time 
needed for the subterranean P. yadonii tuber to develop, prior to the 
emergence of the first leaf above ground, is unknown. In other orchid 
species, this subterranean phase lasts from 1 to 15 years, with 2 to 4 
years the most common among those reported (Wells 1981, pp. 282-283; 
Rasmussen 1995, pp. 197-200; Rasmussen and Whigham 1998, p. 50).
    In addition to its essential mycorrhizal fungal associates, Piperia 
yadonii is also affected by other fungal infections (tentatively 
identified as Rhizoctonia spp.) that can result in reproductive 
failure. In a study of several populations, fewer of the diseased 
plants set seed, compared to healthy plants, and diseased plants set 
significantly fewer seed than healthy plants (Doak and Graff 2001, p. 
14). Populations differed in their disease incidence. In 2003 at 
Manzanita County Park, of the 100 flowering individuals sampled, 94 
percent appeared affected by disease and consequently set no to little 
fruit (2 to 4 small seed capsules) (Graff 2003). Of 90 P. yadonii 
plants that flowered and were examined on the Monterey Peninsula, about 
9 percent exhibited tip wilt and complete reproductive failure 
(EcoSystems West 2006, p. 57).
    Orchid seeds are not known to have any physical dormancy mechanisms 
(Baskin and Baskin 1998, pp. 146-147; 482-484) and are thought to be 
relatively short-lived, although recent research indicates that some 
species may form persistent soil seedbanks (Whigham et al. 2006, pp. 
24-30). After seed production, mature Piperia yadonii plants persist as 
dormant tubers in the soil through the late summer and early fall. The 
tuber is the primary form of persistence from year to year and it 
likely regenerates annually during the growing season, as in related 
orchids (USFWS 1996, p. 7). Leaves emerge again above ground after the 
first significant fall rains saturate the soil. No evidence of asexual 
reproduction through tuber division has been reported or was present in 
an examination of 13 excavated tubers (Doak and Graff 2001, pp. 12-17).
    Following emergence of the first leaf above ground, an unknown 
number of years are required before the tubers are large enough to 
flower. Annually, a proportion of the tubers in any given population 
remain dormant underground, producing neither leaves nor flowers. This 
prolonged dormancy appears to be fairly common among orchids, and in 
some species, individuals remain dormant for multiple years before 
appearing again above ground (Hutchings 1987, pp. 715-716; Kery et al. 
2005, pp. 311-319). We have no demographic data on the proportion of 
plants that actually reach flowering size in their lifetime or the 
average number of years an individual may flower in a life time. The 
lifespan of Piperia yadonii has not been studied. Few studies of other 
temperate terrestrial orchids have tracked populations for a decade or 
more; those that have, note that some individuals continued to appear 
above ground for the duration of the 8 to15 years of study (Wells 1981, 
pp. 289-292; Hutchings 1987, pp. 719-720; USFWS 1996, p. 9).
    Within occurrences, Piperia yadonii plants often grow in dense 
clusters, sometimes containing hundreds of

[[Page 61549]]

plants. Up to 70 plants per square meter were recorded during a habitat 
characterization in Monterey pine forest (EcoSystems West 2006, p. 55). 
Allen (1996, unpaginated) noted that the continuous canopy of Monterey 
pine forest enables more continuous plant aggregations than maritime 
chaparral, where the chaparral shrubs are separated by bare ground.
    The recorded range of Piperia yadonii extends from the hills around 
Prunedale and in the Elkhorn Slough watershed, south to the Palo 
Colorado Canyon area of the Big Sur coast, in northern Monterey County, 
California. This is the same geographic range known at the time of 
listing eight years ago (63 FR 43100). Surveys conducted within this 
range since that time have provided more detailed information on the 
distribution of plants at specific locations and about annual 
variability in plant expression above ground.
    Allen (1996, unpaginated) estimated that about 70 percent of the 
total known population of Piperia yadonii is found near the center of 
this range in the Monterey pine forest of the Monterey Peninsula. 
Recent surveys on the Monterey Peninsula identified greater 
concentrations of P. yadonii in forested areas of the Monterey 
Peninsula (Zander Associates and WWD Corporation 2004, all pp.; 
EcoSystems West 2005, p. 3), so the proportion of plants in that area 
may be greater. While censuses of comparable detail to those recently 
conducted on the Monterey Peninsula have not been completed in maritime 
chaparral, Allen's estimate is not likely to have overestimated the 
importance of the Monterey Peninsula forests to this species. P. 
yadonii is primarily found in two habitat types, central maritime 
chaparral and Monterey pine forest. It also grows in the Bishop Pine--
Gowen cypress (Pinus muricata--Cupressus goveniana ssp. goveniana) 
forest community which occurs within the Monterey pine forest on the 
Monterey Peninsula and at Point Lobos Ranch.
    Piperia yadonii is present in some locations where disturbance has 
occurred previously, such as abandoned dirt roads, old trails or trail 
margins, and cut slopes created by past road construction (Allen 1996, 
unpaginated; Doak and Graff 2001, pp. 4-5; Graff et al. 2003), but that 
are not affected by ongoing foot and vehicle traffic. Graff (2006, p. 
5) has noted that when surrounding forest canopies or undergrowth is 
dense, P. yadonii may be primarily found along trails and abandoned 
roads, presumably in response to greater available light levels.
    The primary threats to Piperia yadonii are loss and fragmentation 
of habitat from commercial, agricultural, residential, and intensive 
recreational development (e.g., golf courses, manicured ball fields). 
The historical distribution of P. yadonii prior to being described in 
1990 is unknown, but it likely included much of the historical extent 
of the Monterey pine forest where the species is presently known to 
occur. Logging of the Monterey pine forest began in the late 1700s with 
the arrival of the Spanish in the Monterey Bay area; over the last 200 
years, the forest continued to be logged and converted to agriculture 
and other human uses. Recent estimates of the historical and current 
extent of Monterey pine forest indicate that 37 to 50 percent of the 
Monterey pine forest once found in the Monterey region has been 
eliminated (Huffman and Associates 1994, p. iii; Jones and Stokes 
Associates 1994a, pp. 8-14; Monterey County Planning and Building 
Inspection Department (Monterey County) 2005, p. 3-72). On the Monterey 
Peninsula, the proportion of Monterey pine forest eliminated is 
greater. On those marine terraces and old dune soils that underlie most 
of the Peninsula, less than 20 percent of the historical extent of 
Monterey pine forest is estimated to remain, much of it in fragmented 
and increasingly isolated stands (Jones and Stokes Associates 1994a, 
pp. 14, 34-37).
    Although no comparable acreage estimates have been made for 
maritime chaparral habitats in the northern distribution of P. yadonii, 
these shrublands have been reduced and fragmented by rural residential 
development and conversion of native vegetation to row crops on deeper 
valley soils. The extent of maritime chaparral destruction in the 
Monterey Bay area was recognized and discussed 30 years ago (Griffin 
1978, p. 78). To the west of Prunedale, most development is apparent in 
the valleys, leaving the vegetation on the shallow soils of ridgelines 
relatively intact, but isolated (aerial photography; Van Dyke et al. 
2001, pp. 221, 226-227). North and east of Prunedale, greater amounts 
of residential development appear to have occurred on the ridgetops. 
Consequently, maritime chaparral patches exist there as smaller 
fragments than they do to the west (mapping by Van Dyke and Holl 2003).
    Maritime chaparral in the Elkhorn-Prunedale region of Monterey 
County is also changing as a result of plant succession and an absence 
of fire. A recent study of maritime chaparral sites first sampled 30 
years ago found that changes in community composition, seedling 
abundance, and canopy cover are occurring after a 70-year absence of 
fire. Shrub diversity appears to be declining and canopy cover is 
increasing as coast live oak (Quercus agrifolia) or large canopied 
manzanitas become dominant (Van Dyke et al. 2001, pp. 225-227). This 
conversion is likely to be slower in the shallow ridgetop soils where 
Piperia yadonii occurs than it is on slopes and more mesic (moist) 
sites, but coast live oak are present now even on these ridgelines (Van 
Dyke et al. 2001, pp. 226-227). Continued fragmentation and isolation 
of ridgetop maritime chaparral habitats in a matrix of residential 
development will reduce the likelihood that fire can be used as a 
management tool in these habitats in the future.
    Other threats that have been identified include invasive nonnative 
plant species and factors that reduce reproduction, such as herbivory, 
disease, and mowing for fuel reduction purposes. The most common 
invasive plant species found in Piperia yadonii habitat throughout its 
range are jubata or pampass grass (Cortaderia jubata) and French broom 
(Genista monspessulana). These are large plants that can form high 
dense canopies, reducing light and space. Jubata grass invades openings 
in maritime chaparral in the Elkhorn-Prunedale region and the 
Huckleberry Hill Reserve on the Monterey Peninsula. French broom is 
more common in Monterey pine forest habitats and was dense in Piperia 
yadonii occurrences at the Naval Postgraduate School and Point Lobos 
Ranch, when abatement was initiated (Graff 2006, appendices IV, VI; 
Greening Associates 1999, p. 4). Other invasive nonnative plants 
documented from occurrences of P. yadonii include rattlesnake grass 
(Briza maxima) and iceplant (Carpobrotus edulis) (Allen 1996; Doak and 
Graff 2001, pp. 4-5). Approximately 20 invasive nonnative plant species 
have been identified spreading in the Monterey pine forests in Monterey 
County (Rogers 2002, pp. 58-59).
    Herbivory of Piperia yadonii leaves and flowering stalks by deer 
and rabbits has been frequently reported (Allen 1996, unpaginated, 
Yadon 1997; Doak and Graff 2001, pp. 10-17). Deer are abundant on the 
Monterey Peninsula and reports from a decade ago estimated that 
herbivory removed about 85 percent of the flowering stalks of uncaged 
plants (Allen 1996, unpaginated). In a study of reproduction in seven 
occurrences, herbivory and disease combined caused reproductive failure 
in about 73 percent of monitored plants (Doak and Graff 2001, p. 17). 
More recent herbivory estimates from both maritime chaparral and 
Monterey pine forest range from 0 percent to 78

[[Page 61550]]

percent, with the highest herbivory rates (73 percent in 2003, 78 
percent in 2005) in the Monterey pine forest (Graff 2006, p. 11, 
Appendix VI). EcoSystems West (2006, pp. 54-58) reported that about 26 
percent of vegetative P. yadonii and about 62 to 70 percent of 
flowering stalks were browsed in Monterey pine forest on the Monterey 
Peninsula.
    Mowing for fuel reduction purposes has repeatedly removed the 
flowering stalks of some Piperia yadonii occurrences in the Monterey 
Peninsula region (Yadon 1997, 2000, unpaginated; Environmental Science 
Associates 2004, pp. 3-14, 3-15, 3-16). Expanded fuel breaks are 
planned for the maritime chaparral in which one occurrence is found at 
Manzanita Park.

Previous Federal Actions

    For more information on previous Federal actions concerning Piperia 
yadonii, refer to the final listing rule published in the Federal 
Register on August 12, 1998 (63 FR 43100). At the time of listing, we 
found the designation of critical habitat for P. yadonii to be not 
prudent because: (1) There would be no additional benefit beyond 
listing from doing so, and (2) it would increase the risk of 
overcollection. In August 2004, we published a recovery plan for P. 
yadonii and four other plant taxa from Monterey County, California 
(USFWS 2004).
    On August 13, 2004, our decision not to designate critical habitat 
for Piperia yadonii was challenged in Center for Biological Diversity 
and the California Native Plant Society v. Norton (Case No. C 04-3240 
(N.D.Cal.). On December 21, 2004, the Court issued a settlement 
agreement, in which the Service agreed to submit for publication a 
proposal to withdraw the existing ``not prudent'' determination 
together with a new proposed critical habitat determination for P. 
yadonii by October 5, 2006.

Prudency Determination

    Section 4(a)(3) of the Act and its implementing regulations (50 CFR 
424.12) require that, to the maximum extent prudent and determinable, 
we designate critical habitat at the time a species is listed as 
endangered or threatened. Our regulations at 50 CFR 424.12(a)(1) state 
that the designation of critical habitat is not prudent when one or 
both of the following situations exist: (1) The species is threatened 
by taking or other activity and the identification of critical habitat 
can be expected to increase the degree of threat to the species or (2) 
such designation of critical habitat would not be beneficial to the 
species. In our August 12, 1998 final rule (63 FR 43100), we determined 
that designation of critical habitat for P. yadonii was not prudent 
based on both reasons. Specifically, we stated that P. yadonii occurs 
predominantly on private lands where Federal involvement is unlikely. 
Furthermore, we stated that a majority of P. yadonii individuals are on 
lands of a single private landowner, who commissioned the studies that 
documented the species' range and population status; because this 
landowner is well aware of the presence and location of the species on 
its property, there would be no additional benefit to the species from 
providing the same location information to the landowner.
    In addition, we stated that publication of precise maps and 
descriptions of critical habitat would make these plants more 
vulnerable to incidents of vandalism which could contribute to the 
decline of the species and therefore such designation would provide 
little conservation benefit over that provided by listing. However, in 
the past few years, several of our determinations that the designation 
of critical habitat would not be prudent have been overturned by court 
decisions. For example, in Conservation Council for Hawaii v. Babbitt, 
the United States District Court for the District of Hawaii ruled that 
the Service could not rely on the ``increased threat'' rationale for a 
``not prudent'' determination without specific evidence of the threat 
to the species at issue (2 F. Supp. 2d 1280 [D. Hawaii 1998]).
    Additionally, in Natural Resources Defense Council v. U.S. 
Department of the Interior, the United States Court of Appeals for the 
Ninth Circuit ruled that the Service must balance, in order to invoke 
the ``increased threat rationale,'' the threat against the benefit to 
the species of designating critical habitat (113 F. 3d 1121, 1125 [9th 
Cir. 1997]).
    We have reconsidered our evaluation of the threats posed by 
vandalism and overcollection in the prudency determination. Since the 
time of listing in 1998, we have gathered information indicating that 
populations of Piperia yadonii continue to be directly and indirectly 
affected by destruction and alteration of habitat due to residential 
development. However, we have no credible information that this species 
has been threatened from vandalism and overcollection, nor can we say 
that critical habitat would not be a benefit to the species. 
Accordingly, we withdraw our previous determination that the 
designation of critical habitat is not prudent for P. yadonii, and 
determine that the designation of critical habitat is prudent for P. 
yadonii. At this time, we have sufficient information necessary to 
identify specific areas that contain features essential to the 
conservation of the species and are, therefore, proposing critical 
habitat (see ``Methods'' sections below for a discussion of information 
used in our reevaluation).

Critical Habitat

    Critical habitat is defined in section 3 of the Act as--(i) the 
specific areas within the geographical area occupied by a species, at 
the time it is listed in accordance with the Act, on which are found 
those physical or biological features (I) essential to the conservation 
of the species and (II) that may require special management 
considerations or protection; and (ii) specific areas outside the 
geographical area occupied by a species at the time it is listed, upon 
a determination that such areas are essential for the conservation of 
the species. Conservation, as defined under section 3 of the Act means 
to use and the use of all methods and procedures that are necessary to 
bring any endangered species or threatened species to the point when 
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 be otherwise relieved, may include regulated taking.
    Critical habitat receives protection under section 7 of the Act 
through the prohibition against destruction or adverse modification of 
critical habitat with regard to actions carried out, funded, or 
authorized by a Federal agency. Section 7 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 government or public access to private 
lands. Section 7 is a purely protective measure and does not require 
implementation of restoration, recovery, or enhancement measures.
    To be included in a critical habitat designation, the habitat 
within the area occupied by the species must first have features that 
are essential to the conservation of the species. 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 (i.e., areas on which are found the

[[Page 61551]]

primary constituent elements, as defined at 50 CFR 424.12(b)).
    Habitat occupied at the time of listing may be included in critical 
habitat only if the essential features thereon may require special 
management or protection. Thus, we do not include areas where existing 
management is sufficient to conserve the species. (As discussed below, 
such areas may also be excluded from critical habitat pursuant to 
section 4(b)(2).) Areas outside the geographic area occupied by the 
species at the time of listing may only be included in critical habitat 
if they are essential for the conservation of the species. Accordingly, 
when the best available scientific data do not demonstrate that the 
conservation needs of the species require additional areas, we will not 
designate critical habitat in areas outside the geographical area 
occupied by the species at the time of listing. An area currently 
occupied by the species but was not known to be occupied at the time of 
listing will likely, but not always, be essential to the conservation 
of the species and, therefore, typically included in the critical 
habitat designation.
    The Service's Policy on Information Standards Under the Endangered 
Species Act, published in the Federal Register on July 1, 1994 (59 FR 
34271), and Section 515 of the Treasury and General Government 
Appropriations Act for Fiscal Year 2001 (Pub. L. 106-554; H.R. 5658) 
and the associated Information Quality Guidelines issued by the 
Service, provide criteria, establish procedures, and provide guidance 
to ensure that decisions made by the Service represent the best 
scientific data available. They require Service 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 
determining which areas are critical habitat a primary source of 
information is generally the listing package for the species. 
Additional information sources 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, and other unpublished materials and 
expert opinion or personal knowledge. All information is used in 
accordance with the provisions of Section 515 of the Treasury and 
General Government Appropriations Act for Fiscal Year 2001 (Pub. L. 
106-554; H.R. 5658) and the associated Information Quality Guidelines 
issued by the Service.
    Section 4 of the Act requires that we designate critical habitat on 
the basis of the best scientific data available. Habitat is often 
dynamic, and species may move from one area to another over time. 
Furthermore, we recognize that designation of critical habitat may not 
include all of the habitat areas that may eventually be determined to 
be necessary for the recovery of the species. For these reasons, 
critical habitat designations do not signal that habitat outside the 
designation is unimportant or may not be required for recovery.
    Areas that support populations, but are outside the critical 
habitat designation, will continue to be subject to conservation 
actions implemented under section 7(a)(1) of the Act and to the 
regulatory protections afforded by the section 7(a)(2) jeopardy 
standard, as determined on the basis of the best available information 
at the time of the 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, or 
other species conservation planning efforts if new information 
available to these planning efforts calls for a different outcome.

Methods

    As required by section 4(b)(2) of the Act, we use the best 
scientific data available in determining areas that contain features 
that are essential to the conservation of Piperia yadonii. This 
includes information from the final listing rule; data from research 
and survey observations published in peer-reviewed articles; reports 
and survey forms prepared for Federal, state, local agencies, and 
private corporations; site visits; regional Geographic Information 
System (GIS) layers, including soil and species coverages; and data 
submitted to the California Natural Diversity Database (CNDDB). We have 
also reviewed available information that pertains to the ecology, life 
history, and habitat requirements of this species. This material 
included information and data in peer-reviewed articles, reports of 
monitoring and habitat characterizations, reports submitted during 
section 7 consultations, our recovery plan, and information received 
from local species experts. We are not proposing to designate as 
critical habitat any areas outside the geographical area presently 
occupied by the species.
    The range of Piperia yadoni extends from the Los Lomos area near 
the Santa Cruz County border in the north to approximately 15 miles (25 
kilometers) south of the Monterey Penninsula near Palo Colorado Canyon 
(Morgan and Ackerman 1990, 208-210; Allen 1996, unpaginated). This 
range has been divided into the following 5 geographic areas for the 
purposes of recovery planning efforts: (1) The Monterey Peninsula, (2) 
the area interior of the Monterey Peninsula, (3) northern Monterey 
County-Prunedale-Elkhorn, (4) the Point Lobos Ranch area, and (5) the 
Palo Colorado Canyon area (USFWS 2004, pp. 16-26, 50-52). We make 
reference to these geographic areas when describing the locations of P. 
yadoni populations and lands proposed for critical habitat designation.

Primary Constituent Elements

    In accordance with section 3(5)(A)(i) of the Act and regulations at 
50 CFR 424.12, in determining which areas to propose as critical 
habitat, we consider those physical and biological features (PCEs) that 
are essential to the conservation of the species, and within areas 
occupied by the species at the time of listing, that may require 
special management considerations and protection. These include, but 
are not limited to space for individual and population growth and for 
normal behavior; food, water, air, light, minerals, or other 
nutritional or physiological requirements; cover or shelter; sites for 
breeding, reproduction, and rearing (or development) of offspring; and 
habitats that are protected from disturbance or are representative of 
the historic geographical and ecological distributions of a species.
    The specific PCEs required for Piperia yadonii are derived from the 
biological needs of P. yadonii as described in the Background section 
of this proposal and below.

Space for Individual and Population Growth, Including Sites for Seed 
Dispersal and Germination

    Piperia yadonii depends on adequate space for growth, reproduction 
between near and far neighbors, and for movement of seeds via wind to 
unoccupied microsites within populations, to population boundaries, and 
to new sites. Once dispersed, seeds must settle into sites with 
characteristics appropriate for germination, including the presence of 
fungal associates necessary for post-germination development. Maritime 
chaparral and pine forest communities in which P. yadonii and its 
fungal symbionts occur, exhibit considerable

[[Page 61552]]

variability in vegetation density, species composition, and unvegetated 
gaps such that microsites appropriate for germination and growth are 
distributed unevenly throughout this mosaic.
    Plant communities such as maritime chaparral, Monterey pine forest, 
and coast live oak woodland are dynamic; in the absence of fire, 
maritime chaparral succeeds to oak woodland in mesic sites and to low-
diversity stands of large old-age manzanitas in drier sites (Van Dyke 
et al. 2001). The patchy distribution of P. yadonii in a given forest 
or chaparral site in a single year is a reflection of the habitat 
conditions at that particular time. Habitat sites that contain the same 
soil characteristics and plant community may become suitable and 
occupied in future decades as vegetation structure changes due to shrub 
or tree death and growth or herbivore population sizes or movements. In 
the same manner, a currently occupied location may diminish in value 
due to these changing conditions. The mosaic of vegetation height, 
density, and species composition in a given area provides opportunities 
for gene flow between occurrences of P. yadonii through seed dispersal 
on prevailing winds, and promotes continuation of ecosystem processes, 
such as the biological interactions necessary to maintain forest canopy 
and dominant manzanita species, and pollinator assemblages.
    Maintaining large and small populations of Piperia yadonii is 
essential for the long-term conservation of the species. Large 
occurrences of plants and those with higher densities of individuals, 
are more likely to attract insect pollinators necessary for the 
production of viable seed and promote gene flow (Kunin 1997, p. 232-
233), to withstand periodic extreme environmental stresses (e.g., 
drought, disease), and may act as important ``source'' populations to 
allow recolonization of surrounding areas following periodic extreme 
environmental stresses. Small populations of plants may serve as 
corridors for gene flow between larger populations, and may harbor 
greater levels of genetic diversity than predicted for their size 
(Lesica and Allendorf 1995, pp. 172-175).

Nutritional and Physiological Requirements, Including Light and Soil 
Requirements

    Piperia yadonii occurs in maritime chaparral, a coastal shrub 
association dominated by endemic species of manzanitas. It is most 
often found on ridges where exposed sandstone or decomposed granitic 
soils are shallow and where the dominant manzanita species are low-
growing (preliminary measurements indicate an average of 6 inches (15 
cm) tall (Graff 2006, pp. 5-6)), allowing P. yadonii leaves to receive 
filtered sun and the inflorescence to extend above the decumbent 
manzanita branches. In the Elkhorn-Prunedale area, the transition from 
the low-growing manzanitas of the ridgetops to the surrounding slopes 
that support deeper soils and higher vegetation canopies is often 
abrupt (Van Dyke et al. 2001, p. 222).
    Although Piperia yadonii grows among manzanitas, the specific 
manzanita species vary among the geographic areas within the species 
range. Hooker's manzanita (Arctostyphylos hookeri ssp. hookeri) is the 
manzanita species with which P. yadonii most commonly grows at its most 
northern distribution in the hills around Prunedale. Pajaro manzanita 
(Arctostaphylos pajaroensis) and chamise (Adenostoma fasciculatum) are 
other dominant shrubs in maritime chaparral there. On and south of the 
Monterey Peninsula, several manzanitas (A. hookeri, A. tomentosa, and 
A. glandulosa ssp. zacaensis) are reportedly the dominant shrubs among 
which it grows (Graff 2006, p. 4; EcoSystems West 2006, p. 64). Other 
species of manzanitas (A. glandulosa) and manzanita hybrids are the 
dominant low-growing forms at the southernmost occurrence of P. yadonii 
near Palo Colorado Canyon, where Hooker's manzanita is absent (Norman 
1995, Graff 2006, p. 4).
    In Monterey pine forest, Piperia yadonii grows through pine needle 
duff where the native herbaceous vegetation cover is typically sparse, 
but diverse, and the Monterey pine canopy is of moderate density (20 to 
70 percent, on the Monterey Peninsula), providing filtered sunlight to 
the forest floor (EcoSystems West 2006, pp. 43, 62-68). The understory 
plant species most frequently associated with P. yadonii in the 
Monterey pine forest are the perennial herb common sanicle (Sanicula 
laciniata), leafy bent grass (Agrostis pallens), and spindly forms of 
bush monkey flower (Mimulus aurantiacus). In a habitat characterization 
of P. yadonii on the Monterey Peninsula, microsites occupied by P. 
yadonii had five times greater cover by other native geophytes 
(perennial plants with underground storage organs, such as bulbs, 
tubers or corms), such as golden brodiaea (Tritelia ixiodes), blue 
dicks (Dichelostemma capitatum), and mariposa lilies (Calochortus spp.) 
than did microsites lacking P. yadonii. Where a maritime chaparral 
understory exists with scattered pines, P. yadonii occurs with other 
native herbs in gaps between the shrubs. It occurs in similar gaps 
associated with trails and fire roads in the Bishop pine--Gowen cypress 
forest stand within the Monterey pine forest on the Monterey Peninsula. 
It is not typically found in areas with a coast live oak canopy or 
those with high understory cover of shrubs or vines (EcoSystems West 
2006, pp. 50-51, 62-68).
    It is likely that in some areas the composition and cover of the 
Monterey pine herbaceous understory may remain relatively stable for 
decades due to abiotic factors (e.g., soils, hydrology) and in others 
these appropriate microhabitats may be ephemeral, disappearing as 
shrubs establish or increase in size and appearing elsewhere when 
understory fire; burrowing, trailing, and browsing animals; or shrub 
death, create new gaps. Areas should be of sufficient size to sustain 
the plant communities in which Piperia yadonii grows, and have 
appropriate soil moisture, and mycorrhizal associates (Perry et al. 
1990, pp. 266-274; Field et al. 1999, pp. 1-3; Noss 2001, pp. 581-586).
    Although soils supporting native mycorrhizal symbionts are believed 
to be a requirement for successful growth in Piperia yadonii, this is 
not a habitat feature easily observable in the field or about which we 
have specific information. Therefore, we have not included it as a 
primary constituent element of critical habitat, but assume that 
mycorrhizal associates will be represented in areas which encompass 
appropriate vegetation and soils.
    Piperia yadonii occupies soils that are primarily characterized as 
sands, fine sands, and sandy loams by the Soil Conservation Service 
mapping (United States Department of Agriculture (USDA) 1978, maps; 
EcoSystems West 2006, pp. 23-26). Soils where P. yadonii occurs in the 
Monterey pine forest are typically characterized as sands, rather than 
loams and, on the Monterey Peninsula, soils are frequently underlain by 
a claypan that is 1 to 5 feet (0.3 to 1.5 m) below the surface (USDA 
1978, pp. 53-54; Jones and Stokes Associates 1994b, pp. 16-21; 
EcoSystems West 2006, pp. 23-26)). In a comparison of Monterey pine 
forest sites on and east of the Monterey Peninsula, P. yadonii was 
present in soils that tended to have lower organic matter, lower 
nutrient levels, and lower summer soil moisture levels than areas where 
it was absent (EcoSystems West 2006, pp. 43, 59-61). It is not known if 
P. yadonii actually prefers nutrient-poor soils or if it is

[[Page 61553]]

unable to compete with the denser understory vegetation found on more 
nutrient-rich soils. P. yadonii presence is correlated with the drier 
of the forest soils. It is not found in riparian areas or wetlands on 
the Monterey Peninsula (Allen, unpaginated; EcoSystems West 2006, pp. 
59-61, 64-65).
    In the maritime chaparral at its northern distributional limit, 
Piperia yadonii occurs on ridges supporting shallow, weathered, sandy 
soils with sandstone outcrops, where shrubs are small-statured (USDA 
1978, pp. 10-11; Allen 1996 unpaginated; Graff 2006, p. 4). The average 
shrub canopy height in areas where P. yadonii occurs on these ridges is 
about 6 inches, according to preliminary sampling (Graff 2006, pp 5-6). 
Soils in this region are typically derived from weathered marine 
deposits. These sites often support cryptogamic soil crusts (soil 
surface communities primarily composed of cyanobacteria, lichens, 
mosses, and algae) (Graff 2006, p. 4). Cryptogamic crusts have been 
found to increase nutrient availability to plants, reduce erosion, 
improve plant-water relations, and provide germination and seedling 
growth sites (USDA 1997, pp. 8-11).

Pollinators

    Piperia yadonii also requires pollinators for the production of 
viable seeds (PCE 2) (Doak and Graff 2001, p. 15). Size and 
configuration of plant populations, and associated flowering species, 
may influence the degree to which pollinators are attracted to an area 
(Sipes and Tepedino 1995, p. 937). The abundance of pollinators may 
affect reproductive success and persistence of small plant populations 
(Groom 1998, pp. 487-495). As a group, the reproductive output of 
orchids is limited by pollinator availability or activity (Tremblay et 
al. 2005, p. 24) and P. yadonii had reduced seed set under natural 
pollination as compared to manual pollination (Doak and Graff 2001, p. 
12-13), an indication that seed set in this species may be pollinator 
limited. When populations of flowering individuals are small or 
flowering is restricted to a specific season, the individual plant 
population may not be able to sustain a population of insect 
pollinators by itself (Groom 1998, pp. 493-495); therefore, habitats 
that support a variety of other flowering plant species that provide 
nectar and pollen sources throughout spring and summer for pollinator 
populations are likely needed to sustain P. yadonii populations.
    Doak and Graff (2001, p. 13) found that pollinators of Piperia 
yadonii are predominantly nocturnal, short-tongued moths e.g., in the 
families Pyralidae, Geometridae, Noctuidae, Pterophoridae) that are 
most active between the hours of 8:30 p.m. and 10:00 p.m. Some of these 
pollinator species (e.g., Agrotis ipsilon, Udea profundalis) are 
generalists regarding larval host plants, but others (e.g., Elpiste 
marcescaria, Drepanulatrix baueraia) feed on specific host plants in 
the larval stage (e.g., coyote bush, wild lilac, respectively). P. 
yadonii exists within several plant communities which sustain insect 
pollinators. They do so by supporting those flowering plant species 
needed by pollinators as larval hosts or nectar sources (e.g., 
coyotebush, wild lilac, and species in the mint family).

Primary Constituent Elements for Piperia yadonii

    Pursuant to our regulations, we are required to identify the known 
physical and biological features (Primary Constituent Elements; PCEs) 
essential to the conservation of Piperia yadonii. All areas proposed as 
critical habitat for P. yadonii are occupied, within the species' 
historic geographic range, and contain sufficient PCEs to support life 
history functions for this species.
    Based on our current knowledge of the life history, biology, and 
ecology of the species and the requirements of the habitat to sustain 
the essential life history functions of the species, we have determined 
that the Piperia yadonii PCEs are:
    1. A vegetation structure providing filtered sunlight on sandy 
soils:
    a. Pine forest (primarily Monterey pine) with a canopy cover of 20 
to 70 percent, and a sparse herbaceous understory on Baywood sands, 
Narlon loamy fine sands, Sheridan coarse sandy loams, Tangair fine 
sands, Santa Lucia shaly clay loams and Chamise shaley clay loams 
underlain by a hardpan.
    b. Maritime chaparral ridges with dwarfed shrub (primarily Hooker's 
manzanita) on Reliz shaly clay loams, Sheridan sandy loams, Narlon 
sandy loams, Arnold loamy sands and soils in the Junipero-Sur complex, 
Rock Outcrop-Xerorthents Association, and Arnold-Santa Ynez complex 
often underlain by rock outcroppings.
    2. Presence of nocturnal, short-tongued moths in the families 
Pyralidae, Geometridae, Noctuidae, and Pterophoridae.
    This proposed designation is designed for the conservation of those 
areas containing PCEs necessary to support the life history functions 
that were the basis for the proposal. Because not all life history 
functions require all the PCEs, not all proposed critical habitat will 
contain all the PCEs.
    Units are designated based on sufficient PCEs being present to 
support one or more of the species's life history functions. Some units 
contain all PCEs and support multiple life processes, while some units 
contain only a portion of the PCEs necessary to support the species' 
particular use of that habitat. Where a subset of the PCEs is present 
at the time of designation, this rule protects those PCEs and thus the 
conservation function of the habitat.

Criteria Used To Identify Critical Habitat

    As required by section 4(b)(2) of the Act, we use the best 
scientific data available in determining areas that contain features 
that are essential to the conservation of Piperia yadonii. This 
includes information from the final listing rule; data from research 
and survey observations published in peer-reviewed articles; reports 
and survey forms prepared for Federal, state, and local agencies, and 
private corporations; site visits; regional Geographic Information 
System (GIS) layers, including soil and species coverages; and data 
submitted to the California Natural Diversity Database (CNDDB). We are 
not proposing to designate as critical habitat any areas outside the 
geographical area presently occupied by the species.
    We have also reviewed available information that pertains to the 
ecology, life history, and habitat requirements of this species. This 
material included information and data in peer-reviewed articles, 
reports of monitoring and habitat characterizations, reports submitted 
during section 7 consultations, our recovery plan, and information 
received from local species experts.
    We are proposing to designate critical habitat on lands within the 
geographic area occupied by the species at the time of listing and 
continue to be occupied to date. All proposed units contain habitat 
with features essential to the conservation of Piperia yadonii. We are 
not proposing any units that are unoccupied.
    We used a multi-step process to identify and delineate proposed 
critical habitat units. First, we mapped and reviewed all known 
occurrences of Piperia yadonii, using the best available information. 
To be meaningful for the purposes of determining proposed critical 
habitat units, survey information had to be evaluated in light of the 
species' life history. Not all individuals produce leaves or flower 
every year. A below-ground P. yadonii tuber can do one of four things 
in any given year: die, remain dormant, send up leaves but not

[[Page 61554]]

flower, or leaf out and flower (Graff 2006, pp. 7 and 8). The length of 
tuber dormancy is not known, but may be from 1 to 4 years based upon 
data from other orchid species with a similar life history. The P. 
yadonii flower is diagnostic (with regard to other Piperia species), 
and the proportion of vegetative plants that flower in any given year 
has been estimated to be from 0.4 percent to 22 percent (Graff 2006, p. 
8), with the lowest estimates coming from the chaparral community. Thus 
it is difficult to precisely determine the extent and abundance of the 
species both within individual occurrences and throughout its 
geographic range. Because a positive identification requires a 
flowering individual, we did not include any occurrences in this 
proposed designation that had not been identified during the flowering 
season as Piperia yadonii.
    Occurrence information included the results of several different 
types of surveys for the species in various locations within its range. 
Allen (1996, unpaginated) conducted a two consecutive year survey to 
better understand the extent of the range, distribution, and overall 
population size of the species. The Allen (1996) study estimated 
populations of Piperia yadonii within polygons overlaid on topographic 
maps, but did not indicate areas where the author looked for, but did 
not find occurrences. Graff (2006, (e.g., pp. 14 and 15) developed a 
long-term monitoring program for P. yadonii, using specific test plots 
in several areas featuring known occurrences, and georeferenced 
individual patches of P. yadonii. Various other surveys were designed 
and conducted for specific purposes, including assessing potential land 
subdivisions/development projects and potential state highway 
realignment. In the case of Pebble Beach Company lands on the Monterey 
Peninsula and areas inland from the peninsula, intensive surveys have 
been conducted in multiple years to aid in planning their Del Monte 
Forest Preservation and Development Plan.
    Next, we evaluated which occupied areas were most likely to 
contribute to the long-term persistence of the species. We focused on 
locations with larger occurrences in larger areas of contiguous native 
habitat (greater than 5 acres (2 ha), see below) that are more likely 
to support intact ecosystem processes and biotic assemblages, provide 
areas for population growth, and opportunities for colonization of 
adjacent areas. These areas also have the highest likelihood of 
persisting through the environmental extremes that characterize 
California's climate and of retaining the genetic variability to 
withstand future introduced stressors (e.g., new diseases, pathogens, 
or climate change). We believe that areas less than 5 acres in size 
that are surrounded by high-density development (e.g., office parks, 
residential neighborhoods, commercial buildings, and parking lots) and 
have become isolated as a result of development may contribute to the 
conservation of the species through educational, research, and other 
mechanisms, but overall have a lower potential for long-term 
preservation and lesser conservation value to the species. Therefore, 
we did not further consider these areas in the proposal. Although we 
have not included these areas within the proposed critical habitat 
designation, because they are, occupied they may still receive indirect 
protection under the Act.
    We then selected sites from among the data set resulting from the 
above evaluati