Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Piperia yadonii (Yadon's piperia), 60410-60450 [07-5136]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 72, Number 205 (Wednesday, October 24, 2007)]
[Rules and Regulations]
[Pages 60410-60450]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 07-5136]



[[Page 60409]]

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Part II





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 
CriticalHabitat for Piperia yadonii (Yadon's piperia); Final Rule

Federal Register / Vol. 72, No. 205 / Wednesday, October 24, 2007 / 
Rules and Regulations

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

RIN 1018-AU34


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

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), are 
designating critical habitat for the endangered Piperia yadonii 
(Yadon's piperia) pursuant to the Endangered Species Act of 1973, as 
amended (Act). In total, approximately 2,117 acres (ac) (857 hectares 
(ha)) fall within the boundaries of the critical habitat designation. 
The critical habitat is located in Monterey County, California.

DATES: This rule becomes effective on November 23, 2007.

ADDRESSES: Comments and materials received, as well as supporting 
documentation used in the preparation of this final rule, are available 
for public inspection, by appointment, during normal business hours, in 
the branch of Endangered Species, at the Ventura Fish and Wildlife 
Office (VFWO), 2493 Portola Road, Suite B, Ventura, CA 93003. The final 
rule, economic analysis, and map are also available on the Internet at 
https://www.fws.gov/ventura.

FOR FURTHER INFORMATION CONTACT: Diane Noda, Field Supervisor, VFWO, at 
the above address (telephone (805) 644-1766, ext. 319; facsimile (805) 
644-3958). Persons who use a telecommunications device for the deaf 
(TDD) may call the Federal Information Relay Service (FIRS) at 800-877-
8339, 7 days a week and 24 hours a day.

SUPPLEMENTARY INFORMATION:

Background

    It is our intent to discuss only those topics directly relevant to 
the designation of critical habitat in this rule. For more information 
on Piperia yadonii, refer to the proposed critical habitat rule 
published on October 18, 2006 (71 FR 61546) and the final listing rule 
published in the Federal Register on August 12, 1998 (63 FR 43100).

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) and proposed critical habitat 
rule published in the Federal Register on October 18, 2006 (71 FR 
61546). On August 7, 2007, we published a notice announcing the 
availability of the draft economic analysis (DEA), and reopening of the 
public comment period (72 FR 44069). This comment period closed on 
September 6, 2007.

Summary of Comments and Recommendations

    We requested written comments from the public on the proposed 
designation of critical habitat for Piperia yadonii in the proposed 
rule published on October 18, 2006 (71 FR 61546). We also contacted 
appropriate Federal, State, and local agencies; scientific 
organizations; and other interested parties and invited them to comment 
on the proposed rule. The initial comment period ended December 18, 
2006. We published newspaper notices on October 26, 2006, in the 
Monterey Herald, Monterey, California, inviting public comment on the 
proposed critical habitat designation.
    During the comment period that opened on October 18, 2006, and 
closed on December 18, 2006, we received 9 comments directly addressing 
the proposed critical habitat designation: 3 from peer reviewers, 1 
from a State agency, and 5 from organizations or individuals. During 
the comment period that opened on August 7, 2007, and closed on 
September 6, 2007, we received 8 comments directly addressing the 
proposed critical habitat designation and the draft economic analysis. 
All of these latter comments were from organizations or individuals and 
some organizations and individuals provided comments during both 
comment periods. Overall, 12 commenters supported a designation of 
critical habitat for P. yadonii, and 3 commenters opposed parts of the 
proposed designation. All comments and new information relating to the 
proposed critical habitat designation for P. yadonii are addressed in 
the following summary and incorporated into the final rule as 
appropriate. We did not receive any requests for a public hearing.

Peer Review

    In accordance with our policy published on July 1, 1994 (59 FR 
34270), we solicited expert opinions from three knowledgeable 
individuals with scientific expertise that included familiarity with 
the species, the geographic region in which the species occurs, and 
conservation biology principles. We received responses from all three 
peer reviewers. The peer reviewers generally agreed that the technical 
information and primary constituent elements (PCEs) identified in the 
proposed designation were accurate and that those areas that we did 
propose as critical habitat should be included. However, all three peer 
reviewers suggested that the designation should be expanded to include 
additional areas and increase the size of existing units. They also 
provided additional information, clarifications, and suggestions to 
improve the final critical habitat rule and the conservation of the 
species. Peer reviewer comments are addressed in the following summary 
and incorporated into the final rule as appropriate.
    We reviewed all comments received from the peer reviewers and the 
public for substantive issues and new information regarding critical 
habitat for Piperia yadonii, and address them in the following summary.
Peer Reviewer Comments
    1. Comment: One peer reviewer indicated that the proposed 
designation emphasizes land ownership and proposed land use over 
biological or ecological factors in determining the size and boundaries 
of units. The peer reviewer replicated the process we identified in the 
rule and provided an analysis of six of our proposed subunits in Units 
1, 2, and 3 as support for this assertion. The peer reviewer showed 
that those subunits that were on, or surrounded by, typical (non-
conservation oriented) private lands encompassed a substantially 
smaller proportion of the appropriate surrounding habitat for Piperia 
yadonii than those subunits that were on, or surrounded by, lands owned 
by a conservation-oriented organization. The peer reviewer further 
stated that an unbiased designation of critical habitat could provide 
great conservation benefit to P. yadonii, as evidenced by four policies 
in the County of Monterey General Plan update. These policies emphasize 
conservation of designated critical habitat areas in evaluating and 
approving proposed land uses. The peer reviewer recommended that we 
redo the designation, focusing solely on the presence of PCEs and 
eliminating any bias introduced by assigning preference to a hierarchy 
of land ownership types.
    Our Response: Our method for designating areas as critical habitat 
was described in the proposed rule under the sections ``Criteria Used 
to Identify Critical Habitat'' and ``Mapping'' and is reiterated here. 
See our answer to comment 18. In determining the extent

[[Page 60411]]

of lands necessary to ensure the conservation and persistence of 
Piperia yadonii, we identified all areas that contain those biological 
and physical features essential to the conservation of the species. 
These lands include those that are either already protected, managed, 
or otherwise unencumbered by conflicting use (e.g., undeveloped County 
or City parks, proposed preservation areas). These populations are most 
likely to persist into the future and to contribute to the species' 
survival and recovery. We also included undeveloped Federal and State 
lands, then local agency and private lands with recognized resource 
conservation emphasis (e.g., lands owned by a conservation-oriented 
organization, undeveloped County or City parks), and finally other 
agency and private lands.
    We agree that land use considerations were a factor used to 
delineate the boundaries of some units or subunits; however, we did not 
exclude from consideration any subunits based solely on land ownership. 
In those cases where we determined that a site had the features 
essential to the conservation of Piperia yadonii, we designated the 
site (e.g., Units 2b and 7). Where a site included a mix of land 
ownership (i.e., lands that were owned or proposed for conservation by 
the State and lands that were not), we typically reduced the subunit to 
the boundaries of the conservation-oriented lands, in an effort to 
minimize the designation of lands that were private or were used or 
proposed for activities that would not be conducive to conservation 
(e.g., development) while ensuring that sufficient lands were 
designated in each unit to enable the unit to serve its conservation 
function. We ensured that our designation included areas distributed 
throughout the geographic range of the species and encompassed the 
habitat variation in elevation, soil types, plant communities, and 
distance from the coast (inland versus coastal) present in P. yadonii 
occupied habitat.
    2. Comment: One peer reviewer supported our inclusion of multiple 
subunits east of Highway 101 in the Prunedale Hills (Unit 3). The peer 
reviewer agreed with the Service's reasons for including these subunits 
(to conserve genetic variation and prevent range collapse) and further 
stated that the plant community at these somewhat xeric, less coastally 
influenced sites may be more stable in the long term, with slower rates 
of successional conversion to oak woodland, than those sites to the 
west. The peer reviewer stated that gradual, successional loss of 
suitable habitat may be a significant threat over the long term and 
suggested that, at a minimum, we scan high-resolution aerial 
photographs of currently occupied sites to identify and delineate 
regions where patches of broken canopy and scattered areas of bare 
ground are visible. The peer reviewer provided historical and current 
aerial photography of four subunits in chaparral and one subunit in 
Monterey pine forest to support the assertion that canopy cover 
throughout the range of Piperia yadonii has increased since the 1930s 
and 1940s.
    Our Response: We have considered the information the peer reviewer 
provided and agree that increased canopy cover in the ridgetop maritime 
chaparral of the Prunedale Hills may threaten Piperia yadonii by 
reducing available habitat. We discussed this in the proposed rule 
under the ``Background'' and ``Special Management Considerations or 
Protections'' sections. Although the vegetation cover in the region in 
which Unit 3 is designated may be increasing more slowly than in those 
areas to the west (in the region of Units 1 and 2), the natural lands 
in and around Unit 3 are also more highly fragmented and developed than 
those areas west of Highway 1, around Units 1 and 2. With increasing 
development, the opportunities to use vegetation management tools, such 
as prescribed fire, which both reduce the vegetation canopy and alter 
soil nutrient availability in ways with which the chaparral plant 
community has evolved, are much reduced. Given the information we 
currently have, that greater fragmentation exists and that known 
population sizes of P. yadonii are generally smaller as one moves east 
in Unit 3, we are not proposing to increase the size of the subunits in 
Unit 3 in an attempt to capture areas of more open canopy. We have 
added discussion to the description of Unit 3, recognizing the 
potentially slower successional changes in Unit 3, and will consider 
this information in making conservation recommendations for the entire 
Prunedale Hills area.
    3. Comment: Two peer reviewers questioned our decision not to 
include in the critical habitat designation those areas where Piperia 
yadonii populations inhabit less than 5 acres and are surrounded by 
development. One peer reviewer stated that not including these smaller 
populations is not conducive to the long-term conservation of the 
species, because they may have large impacts on gene flow and genetic 
diversity and because they can provide connectivity to larger 
populations that we did include in the designation. The peer reviewer 
specifically cited areas that support the Fort Ord, Skyline Drive, and 
Monterey Airport populations, none of which we included in the 
proposal. The peer reviewer urged the Service to work with landowners 
and other entities to develop a coordinated conservation strategy for 
these smaller populations.
    Our Response: We recognize that all populations of Piperia yadonii 
may provide conservation value to the species and we indicated this in 
the proposed rule, as the Peer Reviewer acknowledged, by stating ``* * 
* those populations that 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.'' We believe that small areas with surrounding development 
have a lower conservation value to the species because they are less 
likely to have and maintain the features that are essential to the 
conservation of the species. In general, we seek to identify the 
minimum amount and optimum distribution of lands that support the PCEs 
to designate as critical habitat. Therefore, we did not include all 
populations in this designation.
    In determining which sites to select, we concluded that those 
populations that are in highly developed areas are less likely to act 
as intermediaries in facilitating gene flow between populations, 
because pollinators are less likely to successfully move through 
residential and commercial areas to reach these islands of native 
vegetation and because wind-dispersed seeds are less likely to land in 
areas suitable for germination in highly fragmented landscapes. Of the 
specific sites mentioned by the peer reviewer, the Monterey Airport 
property and those fragmented populations along Garden Road are 
surrounded by the greatest level of development. The Skyline Drive site 
(California Natural Diversity Database (CNDDB) element occurrence (EO) 
19) is on the Monterey Peninsula where we designated the larger 
expanses of Monterey pine forest with larger populations of P. yadonii 
(Subunit 6a) and those smaller sites, like Crocker Grove (Subunit 6d), 
that include plant associations not represented elsewhere.
    The Fort Ord site in Marina (CNDDB EO 9) had not been found in over 
a decade, when a single plant was rediscovered in 2006, while we were 
drafting this rule. The second, more recently discovered Fort Ord site, 
near the boundary of the Monterey Airport,

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consists of fewer than 10 plants. We recognize that the Fort Ord sites, 
particularly the northern one, are geographically isolated from other 
concentrations of Piperia yadonii and, if the northern site is found to 
support a population, it may therefore harbor genetic diversity not 
found elsewhere in the range of P. yadonii. As further information on 
the genetic diversity of this species becomes available, we will 
evaluate it and refine our conservation strategy for P. yadonii. 
However, we cannot determine at this time that the area has the 
features that are essential for the conservation of the species. 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 this reason, critical habitat 
designations do not signal that habitat outside the designation is 
unimportant or may not be required for recovery. We will continue to 
work with landowners on the conservation of P. yadonii throughout its 
range, including in those areas that are not designated as critical 
habitat.
    4. Comment: One peer reviewer indicated that there are substantial 
gaps in the scientific information available on the genetics, seed 
dispersal, plant associations, and fire ecology of Piperia yadonii. The 
peer reviewer recommended that we collect this data in order to 
complete the critical habitat designation and to develop management 
strategies for P. yadonii. The peer reviewer provided observations on 
the response of two other Piperia species in California to fire. In one 
example, a small population of P. leptopetala may have been 
substantially reduced in abundance by a chaparral fire and in the 
other, a chaparral fire appears to have stimulated the above-ground 
expression of P. cooperi.
    Our Response: We recognize that information on many attributes of 
the life history, genetics, and habitat needs of Piperia yadonii is 
extremely limited. Our critical habitat designations are based on the 
best scientific and commercial data available at the time of the 
designation. As more complete information becomes available for P. 
yadonii, we will incorporate it into our recovery strategy for this 
species. We appreciate the information the peer reviewer provided on 
fire ecology and recognize that genetic research is being conducted 
that may influence our understanding of genetic diversity within P. 
yadonii. While we do not develop management strategies as part of the 
designation of critical habitat, we do consider site-specific 
management strategies important to the conservation of the species and 
work with land owners, researchers, and others, to develop and 
implement them as part of the recovery process.
    5. Comment: One peer reviewer recommended that we gather more 
information on pollinator flight range and seed dispersal in an attempt 
to determine if the critical habitat units are close enough to allow 
gene flow between them.
    Our Response: We have contacted several research scientists who 
specialize in moths and have reevaluated the available literature on 
pollinators and seed dispersal in orchids. We believe there are no 
additional data available, beyond what we cited in the proposed rule, 
on either the seed dispersal distances of orchids or the flight 
distances of potential pollinators, that would allow us to determine 
the likelihood of gene flow between critical habitat units or subunits. 
While data on the flight distance of relatively large moths in the 
family Sphingidae (sphinx months) exist, very few data are available on 
the distances small moths may transport pollen. In our designation, we 
attempted to address the need to maintain gene flow between patches of 
plants that are within meters of one another. We did so by encompassing 
within the same subunits (e.g., in Units 1 and 2) those patches of 
Piperia yadonii plants that occur on the same ridgeline in maritime 
chaparral, and by encompassing multiple patches of plants within the 
same subunits (e.g., in Unit 6) in Monterey pine forest.
    6. Comment: Two peer reviewers indicated that genetic diversity was 
not adequately considered in the criteria used to designate critical 
habitat. One peer reviewer suggested it could be considered a PCE, or 
that environmental proxies could be used in the absence of information 
on the spatial pattern of genetic variation in Piperia yadonii. One 
peer reviewer noted that genetic research on P. yadonii is underway and 
some results should soon be available.
    Our Response: We agree that little is known about the spatial 
pattern of genetic variation in Piperia yadonii populations, and we are 
aware of, and are interested in, the genetic research on P. yadonii 
being conducted. Based on the Act, PCEs are always habitat features 
rather than intrinsic population characteristics. Therefore, genetic 
diversity cannot be considered a PCE. However, in this designation, we 
did consider that genetic variation may be a reflection of 
environmental variation. We have attempted to encompass variation in 
habitat, as an indicator of populations that may be exposed to 
differing selective pressures, and therefore may have diverged 
genetically and represent a range of genetic variation in P. yadonii. 
As we discussed in the proposed rule under ``Criteria Used to Identify 
Critical Habitat,'' our methods included designating sites that 
encompass the range of elevational differences, plant communities, and 
soil types in which P. yadonii occurs.
    7. Comment: One peer reviewer stated that the designation should be 
more conservation-oriented toward Piperia yadonii, given that the 
species is dependent on biological associates, such as mycorhizzal 
(fungal) associates, Monterey pines, and pollinators. The peer reviewer 
indicated that these close associations make Piperia yadonii more 
vulnerable to environmental changes, such as climate change. The peer 
reviewer, therefore, recommended that the rule contain larger areas and 
additional areas beyond what was included in the proposed designation.
    Our Response: We recognize that relatively little specific 
information exists on the relationship of Piperia yadonii to other 
biological associates within its habitat and the vulnerability of those 
associates to broad-scale environmental changes, such as forest 
structure changes due to pathogens or climate change. We previously 
funded research on P. yadonii's breeding system and pollinators in an 
effort to determine the need for, and potential vulnerability of, 
pollinators. This research found that P. yadonii requires pollinators 
to set seed and is, therefore, highly dependent on pollinators, and 
that several of the likely pollinators of P. yadonii in the Monterey 
pine forest are moth species that have broad ranges and habitat 
preferences. Therefore, we are less concerned about the potential for 
environmental changes to affect pollinators in the Monterey pine forest 
plant communities. We recognize that little is known about the relative 
importance of the various species that pollinate P. yadonii, and that 
virtually nothing is known about pollination of P. yadonii in maritime 
chaparral. Therefore we have attempted to encompass the mosaic of 
adjacent plant community types in which patches of P. yadonii occur. 
Recognizing that larger sized units may potentially reduce the risk to 
P. yadonii from environmental change, we have attempted to designate as 
critical habitat areas of sufficient size to accommodate potential 
environmental changes. We have included reference to climate change in 
the discussion of how the PCEs were derived, but have not increased the 
size of any units beyond what we proposed.

[[Page 60413]]

    8. Comment: One peer reviewer commented that the uncertainty of 
Piperia yadonii's actual range, its patchy distribution, and expected 
impacts of climate change constitute sufficient justification to 
designate units outside P. yadonii's known range. The peer reviewer did 
not provide specific suggestions of locations that should be included.
    Our Response: While we generally agree with the rationale presented 
by the reviewer, we only designate critical habitat in areas outside 
the geographical area occupied by the species at the time of listing 
where the best available information indicates that these areas are 
essential to the conservation of the species. We have included areas 
throughout the range of Piperia yadonii within this designation, 
although not every population has been included. Within each portion of 
P. yadonii's range, we reviewed known locations and surrounding habitat 
that support the PCEs. Based on our current information, we have 
concluded that there are no areas outside the species' known range that 
are essential to the conservation of the species and that therefore 
should be included in the designation.

Comments From the Public

    9. Comment: Two commenters noted the thoroughness and quality of 
the technical information in the background section of the proposed 
rule and in the discussion of the PCEs and generally supported a 
designation of critical habitat for Piperia yadonii. However, one 
commenter questioned why the proposed designation did not include all 
or part of every occurrence of P. yadonii. They recommended that the 
designation include all occurrences of P. yadonii and urged the Service 
to add suitable unoccupied habitat to the designation.
    Our Response: See response to comment 3, above.
    10. Comment: Several commenters stated that the level of detail in 
the maps provided was insufficient to determine what proposed areas are 
included or not included in the designation, both on the Monterey 
Peninsula and in northern Monterey County.
    Our Response: We agree that it is often difficult to distinguish 
unit boundaries based on the resolution of maps published in the 
Federal Register. To provide additional clarity, we attempted to 
include adequate descriptions of the units in the proposed rule. We 
have reviewed those unit descriptions and have provided additional 
clarifying information to them in this final designation. For example, 
for units on the Peninsula, we included area names used in the 
environmental impact report for the Pebble Beach Company's proposed 
development (Monterey County 2005). The public can request more 
explicit maps of the designation by contacting our office using any one 
of the methods listed in the FOR FURTHER INFORMATION CONTACT section 
listed above.
    11. Comment: One commenter requested that the 6-acre portion of 
Stevenson School campus be deleted from critical habitat Subunit 6a, on 
the Monterey Peninsula, because the school intends to convert the 
property to an athletic field for student use in the future. The 
commenter states that, due to the property's small size and location, 
this area is not essential to the conservation of Piperia yadonii, that 
enough habitat is being conserved on the Monterey Peninsula via the 
Pebble Beach Company's proposed mitigation for their development plan, 
and that the inclusion of school property in the proposed designation 
will have adverse impacts on the school. They provided materials 
describing the school and its proposed site plan.
    Our Response: As we developed the designation, we evaluated all 
areas on the Monterey Peninsula that support the PCEs, including the 
area owned by Stevenson School. The Monterey Peninsula is the center of 
distribution of Piperia yadonii and supports over 70 percent of all 
known plants. The Stevenson School property supports Monterey pine 
forest contiguous with a larger extent of Monterey pine forest 
encompassed within Subunit 6a. Because of its connection to other 
Monterey pine forest with a natural understory, we do not consider it 
too small to have the features that are essential to the conservation 
of P. yadonii. Although it has abundant shrub cover in some areas, in 
other areas it supports a more open herbaceous understory with 
scattered patches of P. yadonii (Steeck, 2007). We evaluated the 
materials submitted by the commenter and the potential economic costs 
to Stevenson School from the proposed designation in our draft economic 
analysis. Based on the School's proposed plans for the site, we have 
decided to exclude this property from the final designation of critical 
habitat (see Exclusions Under Section 4(b)(2) of the Act section below 
for more information). We are available to work with Stevenson School 
representatives on the conservation and recovery of P. yadonii and 
their future school development plans.
    12. Comment: One commenter stated that critical habitat on the 
Pebble Beach Company's property should include only those areas 
designated by the Pebble Beach Company for conservation purposes. They 
asserted that other areas are not essential to the conservation of P. 
yadonii. They provided specific recommendations for modifications to 
several subunits, including excising all current and proposed roads 
that pass through the subunits of Unit 6.
    Our Response: We reviewed the materials submitted and grouped the 
requested modifications into four categories: (a) Requests to remove 
all current and proposed roads from the subunits of Unit 6; (b) small 
adjustment in boundaries where the designation appeared to extend 
beyond the boundaries of a proposed conservation or open space area 
into, or just beyond, existing roads or the golf course; (c) requests 
to remove areas supporting existing Monterey pine forest that the 
commenter indicates are ``lots of record'' but that Monterey County 
required be conserved, as mitigation, in the final environmental impact 
report (Monterey County 2005) for the Pebble Beach Company's proposed 
development; and (d) more substantial modifications, which we 
individually discuss in the response to Comment 13, below.
    We addressed the former three categories in the following ways:
    (a) Roads: The Service does not typically map critical habitat at 
this level of detail, due to the time involved in attempting to exclude 
small, linear areas that lack the PCEs and would divide polygons. Lands 
covered by roads or other structures that do not support the PCEs are 
excluded by text in the final rule, as explained in the Mapping 
section. We recognize that some roads currently exist, but that 
adjustments to their current alignments are proposed that would 
eliminate habitat containing the PCEs. We have excluded, under Section 
4(b)(2) of the Act, proposed and existing roads in Unit 6 in 
recognition of the conservation agreement signed by the Service and 
Pebble Beach Company. This agreement and the exclusions are discussed 
further in the section, Relationship of Critical Habitat to Approved 
Management Plans--Exclusions Under Section 4(b)(2) of the Act, below. 
See Summary of Changes from Proposed Rule, below, for more information.
    (b) We have made some adjustments to the boundary of critical 
habitat in Subunit 6a around the corporate yard (a proposed development 
parcel (Monterey County 2005)), along Congress Road near the quarry 
site (extension of

[[Page 60414]]

boundary over a road), and north of area I-1 (where a relatively 
recently constructed structure is visible in 2005 aerial photography).
    (c) We have excluded areas within Subunits 6a and 6c, including 
those referred to by the Pebble Beach Company as areas F-1, J, and part 
of Area L, that support the PCEs of critical habitat and are identified 
as required mitigation areas, with some allowance for development, in 
the FEIR for Pebble Beach Company's proposed development (Monterey 
County 2005). We make these exclusions in recognition of the 
conservation agreement signed by the Service and Pebble Beach Company. 
This agreement and the exclusions are discussed further in the section, 
Relationship of Critical Habitat to Approved Management Plans--
Exclusions Under Section 4(b)(2) of the Act, below. See Summary of 
Changes from Proposed Rule, below, for more information.
    13. Comment: A commenter representing the Pebble Beach Company 
suggested that we consider that two areas included in Unit 6 of the 
proposal, Indian Village/Area L (Subunit 6c) and Area B (Subunit 6e), 
contain greater shrub cover or riparian habitat than Piperia yadonii 
typically prefers. They also recommended we remove a portion of Subunit 
6a referred to as Area D and reduce Unit 4 (Aguajito), to encompass 
only the suitable low-growing maritime chaparral habitat contiguous 
with the existing occurrence.
    Our Response: We have retained both Area B and its adjacent 
forested areas in Subunit 6e, as well as part of Area L and adjacent 
forest (Indian Village) in subunit 6c in this designation, because they 
contain the PCEs for Piperia yadonii. We have concluded that these 
areas have the features that are essential to conserve P. yadonii. We 
have excluded 2 ac (0.8 ha) of Subunit 6e (Area B) and about 9 acres (4 
ha) of Area L in recognition of the overall benefits that designated 
critical habitat areas will receive under the conservation agreement 
signed by the Service and the Pebble Beach Company (see the section 
Relationship of Critical Habitat to Approved Management Plans--
Exclusions Under Section 4(b)(2) of the Act below for a discussion of 
this exclusion).
    For Unit 4 (Aguajito), we have reviewed the habitat proposed in the 
subunits and have considered the unique nature of the maritime 
chaparral on the shale and sandstone-derived soils within a large 
expanse of maritime chaparral and Monterey pine forest and concluded 
that the subunits we are designating contain the features essential to 
the conservation of P. yadonii. However, we have excluded 49 acres of 
this unit in recognition of the overall benefits that Unit 4 will 
receive under the conservation agreement signed by the Service and the 
Pebble Beach Company (see the section Relationship of Critical Habitat 
to Approved Management Plans--Exclusions Under Section 4(b)(2) of the 
Act below for a discussion of this exclusion).
    We have reviewed the habitat in subunit 6a, Area D, and agree with 
the commenter that it does not contain the features essential for the 
conservation of Piperia yadonii. We conclude that the dominance of 
coast live oak and open canopy with relatively few Monterey pines makes 
it less suitable for P. yadonii. Therefore, we have removed 35 ac (14 
ha) of Subunit 6a that do not contain the PCEs from this final critical 
habitat designation. See Summary of Changes from Proposed Rule, below, 
for more information.
    14. Comment: Three commenters recommended expansion of Subunit 6a 
to include Area F-2, about 17 acres (7 ha) in Area F3, and an 
additional 13 ac (5 ha) of Area PQR, as defined in the Pebble Beach 
Company's proposed development.
    Our Response: We did not propose or designate Areas F-2, most of F-
3, or the 13 ac (5 ha) in PQR because these locations support fewer 
Piperia yadonii plants compared to other locations in the Del Monte 
Forest that we are designating as critical habitat. These areas are 
also proposed for development by the Pebble Beach Company. Although we 
proposed conservation area F-1 as critical habitat, it is part of the 
exclusion we are making in this final designation, based on the 
conservation agreement we have signed with the Pebble Beach Company. 
See the section Relationship of Critical Habitat to Approved Management 
Plans--Exclusions Under Section 4(b)(2) of the Act below for a 
discussion of this exclusion. Please also see our response to Comment 1 
and 18.
    15. Comment: One commenter suggested that the Service should expand 
Subunit 6b to include all of Area MNOUV, which supports one of the two 
largest occurrences of Piperia yadonii known to exist. Area MNOUV is 
the name given to the collective areas that support 116 acres of 
Monterey pine forest and are proposed for development as a golf course 
by the Pebble Beach Company. The commenter referred to language in our 
proposed designation in which we indicated that the conservation role 
of P. yadonii critical habitat units is to support viable core 
populations. The commenter stated that Area MNOUV supports one of two 
viable core populations on the Peninsula and, as such, the Service 
should follow its own guidelines and include it in the designation.
    Our Response: Please see our response to Comment 18 for a 
description of how we designated critical habitat. We recognize that 
Subunit 6b is just one part of the large Piperia yadonii population 
found in Area MNOUV. Area MNOUV supports one of the two largest 
occurrences known to exist and is distributed within the second largest 
expanse of Monterey pine forest known to support P. yadonii. However, 
the Service determined the area did not have the features that are 
essential to the conservation of the species. We determined the 
quantity and spatial characteristics of habitat needed for 
conservation, and this area was determined not to meet the definition 
of critical habitat. Please also see our response to Comment 1.
    16. Comment: One commenter asked if Subunits 3b and 3c were 
verified to support Piperia yadonii.
    Our Response: According to data supplied by the California 
Department of Transportation (Caltrans) during the preparation of the 
proposed rule (Robison 2006), populations of Piperia yadonii in 
Subunits 3b and 3c were visited while in flower and were verified to 
support the species.
    17. Comment: One commenter provided observations of habitat and 
population conditions of Piperia yadonii in and around Subunit 3a and 
suggested the designation be expanded to include a site near Subunit 3a 
that may contain many more P. yadonii than previously documented. The 
commenter stated that the planning process for the parcel where the 
population occurs did not appear to involve adequate surveys for P. 
yadonii, because the surveys were conducted during the fall. The 
commenter provided suggestions for protecting this site.
    Our Response: We appreciate the technical information supplied and 
have incorporated it into the discussion of Subunit 3a, where 
appropriate. The population in question near Subunit 3a should be 
surveyed to get a positive identification of the Piperia species 
occurring there. Because we cannot determine at this time that the area 
meets the definition of critical habitat, we are not designating it in 
this final rule. The process of designating critical habitat does not 
involve the creation of preserves or management strategies; however, we 
frequently provide conservation recommendations to local agencies, and 
work with Federal

[[Page 60415]]

agencies through the section 7 consultation process, as we promote 
recovery of listed species. We will consider the technical information 
and suggestions provided by the commenter in planning and implementing 
recovery for this species.

Comments Related to the Draft Economic Analysis

    18. Comment: The Draft Economic Analysis (DEA) fails to present a 
baseline that describes the conditions that would exist in the absence 
of critical habitat designation. Specifically, NPCC commented that the 
DEA estimated a large portion of the costs would be incurred by the 
Pebble Beach Company (PBC), but PBC would incur these costs with or 
without designation. While the DEA ``directly attributed'' PBC's costs 
of invasive species control to designation, invasive species control 
provides many benefits, is required by CEQA, and was conducted in all 
areas, whether or not the species was present. Others commented that 
the DEA attributes delays to the designation that might be due to other 
sources.
    Our Response: The Final Economic Analysis (FEA) includes an 
Appendix which describes impacts expected to result because of the 
designation of critical habitat. That is, the Appendix presents the 
incremental impacts that would not be expected to occur in the absence 
of critical habitat. This appendix recognizes that most of the impacts 
quantified as coextensive impacts in the report are expected to occur 
regardless of the designation of critical habitat.
    19. Comment: The DEA makes no attempt to estimate how many projects 
or actions would involve a Federal nexus in the 20-year analysis and 
that the FEA should base estimates on such a prediction.
    Our Response: Appendix A of the FEA identifies projects that 
involve a Federal nexus to estimate the incremental impacts of the 
designation apart from the coextensive impacts quantified in the DEA.
    20. Comment: It is unlikely that the restriction on development in 
unit 2b is due to the proposed rule. It is also unlikely that the 
development in unit 2b would have been completely prevented.
    Our Response: The DEA does not attribute these impacts from lost 
development to the proposed rule, but describes them as impacts 
``coextensive'' with the designation of critical habitat. The FEA 
includes an Appendix describing incremental impacts. As described in 
Appendix A, the foregone development impacts in unit 2 are not 
considered to be incremental impacts of the critical habitat 
designation. Further, in the specific case of the proposed development 
in unit 2b, the FEA omits most of the impact from lost development that 
was originally included in the DEA, as information suggests it is 
unlikely that the entity will be prevented from developing.
    21. Comment: To estimate the cost of delay, the DEA solely relies 
on conversations with the developer and uses an interest rate of 
fifteen percent without explanation.
    Our Response: The DEA relied as much as possible on the County 
Planning and Building Department to determine what development had 
occurred in the past, what development was currently under review, and 
what development was planned for the future. The developer provided 
reasonable estimates of delay time. An interest rate of fifteen percent 
is a standard interest rate used to calculate the risk adjusted cost of 
capital to private developers.
    22. Comment: The DEA estimates on page 34 and 44 costs to PBC of as 
much as $4.5 million associated with invasive species control. 
Commenter states that it is unclear how the overall $4.5 million figure 
was determined.
    Our Response: The DEA does not include any estimated impacts of 
$4.5 million as described. Total impacts to the PBC over 20 years in 
undiscounted dollars of invasive species removal efforts is estimated 
to be $0.97 million in units 4 and 5 (see page 34 of the DEA) and $2.87 
million in unit 6 (see page 44 of the DEA). As cited in footnotes 92 
and 104 of the DEA, impacts to the PBC are based on annual budget 
estimates provided by PBC.
    23. Comment: Commenter states that the DEA does not evaluate the 
evidence the Stevenson School provided on the large adverse impacts to 
the School. The commenter also noted that DEA does not comply with the 
Regulatory Flexibility Act (RFA) or Small Business Regulatory Fairness 
Act (SBREFA) as it does not adequately analyze the impacts to the 
Stevenson School.
    Our Response: The FEA incorporates the previous comments made by 
the Stevenson School and evaluates impacts of piperia conservation on 
the School. Section V.F of the FEA estimates impacts to range from 
$0.006 million to $9.2 million (present value, three percent discount 
rate) as a result of possible restrictions on the implementation of the 
School's Master Plan. The FEA also considers the impacts to the 
Stevenson School in the RFA and SBREFA.

Comments from the State

    24. Comment: The California Coastal Commission questioned why the 
critical habitat designation on the Monterey Peninsula did not include 
any areas proposed for development by the Pebble Beach Company, 
including that part of the Monterey pine forest that supports roughly 
one-third of the known population of Piperia yadonii and is proposed 
for a golf course. The Coastal Commission noted that the Service 
provided no biological justification for the absence of this area in 
the designation. They recommended that the critical habitat be redrawn 
to include Monterey pine forest areas on the Monterey Peninsula that 
support P. yadonii and its habitat.
    Our Response: During the process of selecting critical habitat 
boundaries, we determined the PCEs for the species, and identified the 
quantity and spatial characteristics of PCEs needed for conservation. 
These are the physical and biological features essential to the 
conservation of the species. In determining the appropriate spatial 
arrangement of PCEs, we identified areas where there were conflicts 
with development projects and assessed the likelihood of the species' 
persistence and recovery absent designation of those areas. We 
determined that there was sufficient habitat for the species 
conservation without these lands. Therefore, our critical habitat 
designation does not include Pebble Beach Company development lands.
    We used a multi-step process to identify and delineate critical 
habitat units. First, we reviewed and mapped all known occurrences of 
Piperia yadonii, using the best available information. Next, we 
determined the physical and biological features essential to the 
conservation of the species. To do this we defined the PCEs and then 
determined which areas contain PCEs that are essential to the 
conservation of the species. 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. We then selected sites with the PCEs 
that: (a) Represented the geographic range of the species; (b) captured 
peripheral populations; (c) included the range of plant communities and 
soil types in which P.

[[Page 60416]]

yadonii is found; (d) encompassed the elevation range over which the 
species occurs; and (e) maintained the connectivity of occurrences that 
grow on continuous ridgelines. From these areas we selected populations 
are most likely to persist into the future and to contribute to the 
species' survival and recovery. Other areas that we determined to have 
the PCEs, that were not included in the proposed designation or this 
final designation, did not have the features that are essential to the 
conservation of the species. For more information on how critical 
habitat was determined, see Criteria Used To Identify Critical Habitat 
section, below.

Summary of Changes From Proposed Rule

    In preparing the final critical habitat designation for Piperia 
yadonii, we reviewed and considered comments from the public and peer 
reviewers on the proposed designation of critical habitat published on 
October 18, 2006 (71 FR 61546), and public comments on the draft 
economic analysis published on August 7, 2007 (72 FR 44069). As a 
result of comments received on the proposed rule and the DEA, and a 
reevaluation of the proposed critical habitat boundaries, we made 
changes to our proposed designation, as follows:
    (1) Based on exclusions under section 4(b)(2) of the Act, we 
reduced the size of several subunits of Unit 6 on the Monterey 
Peninsula and both subunits of Unit 4 (Aguajito) as discussed in 
responses to Comments 12 and 13 and in recognition of the development 
of a conservation agreement signed by the Service and the Pebble Beach 
Company. Collectively, this resulted in a reduction of Unit 6 from 
1,059 acres (428 ha) to 920 acres (372 ha) and Unit 4 from 157 acres 
(63.5 ha) to 108 acres (43.7 ha). The acreages of the changes are 
provided in Table 2. We also excluded the Stevenson School for economic 
reasons. Further discussion of the conservation agreement and 
exclusions under the Act can be found later in this document starting 
with the section Application of Section 4(a)(3) and Exclusions Under 
Section 4(b)(2) of the Act.
    (2) We added the names of parcels of land, where available, to the 
unit descriptions, to help readers understand the boundaries of the 
designation, given the rather low resolution of the maps. We added 
technical information, as discussed in the comments, to the 
descriptions of Unit 3.

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 at 
which the measures provided under the Act are no longer necessary.
    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(a)(2) of the Act 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 of the Act is a purely protective 
measure and does not require implementation of restoration, recovery, 
or enhancement measures.
    To be included in a critical habitat designation, habitat within 
the geographical 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 (areas on which are found the primary constituent 
elements, as defined at 50 CFR 424.12(b)).
    Unoccupied areas can be designated as critical habitat. However, we 
will designate unoccupied areas only when the best available scientific 
data demonstrate that the conservation needs of the species require 
additional areas.
    Section 4 of the Act requires that we designate critical habitat on 
the basis of the best scientific and commercial data available. 
Further, 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 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. 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.
    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 of Piperia yadonii, 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

[[Page 60417]]

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, and local agencies, and 
private corporations; site visits; regional Geographic Information 
System (GIS) layers, including soil and species coverages; and data 
submitted to the 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, the recovery plan for 
P. yadonii, and information received from local species experts. We did 
not designate as critical habitat any areas outside the geographical 
area occupied by the species at the time of listing.
    The range of Piperia yadonii extends through Monterey County from 
the Las Lomas area near the Santa Cruz County border in the north to 
approximately 15 miles (25 kilometers) south of the Monterey Peninsula 
near Palo Colorado Canyon (Morgan and Ackerman 1990, 208-210; Allen 
1996, unpaginated). This range has been divided into the following five 
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. yadonii populations and lands in this 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 or 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 or 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 the proposed rule 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 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) and 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 
centimeters) 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 
(A. 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 manzanita (A. glandulosa) and manzanita hybrids are

[[Page 60418]]

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); 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, given that 
climate change may eventually alter forest composition (and thus 
availability of filtered sunlight), available 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 for P. yadonii, but assume that mycorrhizal 
associates will be represented in areas that 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, 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 unable to 
compete with the denser understory vegetation found on more nutrient-
rich soils. The presence of P. yadonii 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 sam