[Federal Register Volume 62, Number 118 (Thursday, June 19, 1997)]
[Proposed Rules]
[Pages 33388-33390]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-15926]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

RIN: 1018-AC98


Endangered and Threatened Wildlife and Plants; Withdrawal of 
Proposed Rule to List Arctostaphylos Imbricata (San Bruno Mountain 
Manzanita) as Threatened

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule; withdrawal.

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SUMMARY: The U. S. Fish and Wildlife Service (Service) withdraws the 
proposal to list Arctostaphylos imbricata (San Bruno Mountain 
manzanita) as a threatened species under the Endangered Species Act of 
1973, as amended (Act). This determination is based on evaluation of 
comments and additional information received subsequent to publication 
of the proposed rule. Provisions of the San Bruno Mountain Habitat 
Conservation Plan (HCP) pertaining to management for the conservation 
of A. imbricata have been clarified. Other threats identified in the 
proposed rule pertaining to fire frequency and overutilization for 
horticultural purposes are no longer considered to pose a significant 
risk to the survival of the species. Thus, protection under the Act is 
unnecessary at this time.

ADDRESSES: The complete file for this rule is available for public 
inspection, by appointment, during normal business hours at the 
Sacramento Field Office, U.S. Fish and Wildlife Service, 3310 El Camino 
Ave., Sacramento, California 95821-6340.

FOR FURTHER INFORMATION CONTACT: Diane Windham, at the above address or 
by telephone at (916) 979-2725.

SUPPLEMENTARY INFORMATION:

Background

    Alice Eastwood (1931) originally described Arctostaphylos imbricata 
in 1931, based on material collected from the San Bruno Hills in 1915. 
Until 1967, various authors either synonymized A. imbricata with A. 
andersonii (Jepson 1939), or considered it to be a variety of A. 
andersonii (Adams in McMinn 1935). Roof (1967) followed Eastwood's 
treatment and acknowledged A. imbricata as a distinct species. Wells 
(1988) recognized A. montariensis as a subspecies of A. imbricata 
which, under the rules of botanical nomenclature, automatically created 
the name (autonym) A. imbricata ssp. imbricata. He has since revised 
his treatment of California Arctostaphylos to recognize A. imbricata as 
a distinct species (Wells 1993).
    Arctostaphylos imbricata is a low, spreading, evergreen shrub of 
the heath family (Ericaceae) that lacks a basal burl. Attaining a 
height of 20 centimeters (8 inches), this highly branched shrub forms 
mats up to about 6 meters (m) (6 yards) in diameter. The bright green, 
oblong to ovate leaves are hairless, except on the midrib, and densely 
overlapping. Small, white, urn-shaped flowers appearing from February 
to May are densely clustered at the end of branchlets. After fire, A. 
imbricata regenerates from seed instead of resprouting from a basal 
burl. Arctostaphylos imbricata can be distinguished from other members 
of the genus by its prostrate form, its shorter, densely arranged 
leaves, and its compact flower clusters (Roof 1967).
    Arctostaphylos imbricata is restricted to San Bruno Mountain in 
northern San Mateo County. On San Bruno Mountain, six small colonies 
comprise one population which covers approximately 2.3 hectares (5.6 
acres) (V. Harris, Thomas Reid Associates, in litt. 1993; R. Gankin, 
San Mateo County Planning Department, in litt. 1994). The most abundant 
colony has 400 to 500 plants; other colonies have as few as 3 plants 
(R. Gankin, pers. comm. 1993; R. Gankin, in litt. 1994). The plant 
grows on rocky, exposed areas such as open ridges within coastal scrub 
or manzanita scrub vegetation at an elevation range of 275 to 365 m 
(900 to 1,200 feet). Where it occurs, it is the dominant plant species, 
and may be associated with Baccharis pilularis (coyote brush), 
Vaccinium ovatum (huckleberry), Rhamnus californica (coffeeberry), and 
Arctostaphylos uva-ursi var. suborbiculata (bearberry) (California 
Department of Fish and Game 1988). Arctostaphylos imbricata has never 
been known from more than the single population of six colonies that 
occurs today. Five of the six colonies occur on land owned by the San 
Mateo County Department of Parks and Recreation; the sixth colony is 
privately owned (Thomas Reid Associates 1991). All colonies are located 
within the San Bruno Mountain HCP boundaries.

Finding and Withdrawal

    The proposed rule to list Arctostaphylos imbricata as threatened 
(October 4, 1994; 59 FR 50550), stated that the San Bruno Mountain HCP, 
a planning effort under management and implementation by San Mateo 
County and their consultant, Thomas Reid and Associates, identifies A. 
imbricata as a ``species of concern'' but that the HCP does not 
identify any species-specific management actions for this species. 
Since publication of the proposed rule, provisions of the HCP 
pertaining to management for the conservation of A. imbricata have been 
clarified. The HCP preserves most of the mountain and provides 
monitoring and management for a number of rare plant and animal 
species, including A. imbricata. In addition, threats identified in the 
proposed rule pertaining to fire frequency and overutilization for 
horticultural purposes are no longer considered to pose a significant 
risk to the survival of the species. For these reasons, the Service now 
believes the plant is adequately conserved.

Previous Federal Action

    On December 15, 1980, the Service published in the Federal Register 
an updated Notice of Review for plants
(45 FR 82480) which included Arctostaphylos imbricata as a category 1 
candidate for Federal listing. Category 1 taxa were formerly defined as 
taxa for which the Service had on file sufficient information on status 
and threats to support issuance of a listing proposal. Arctostaphylos 
imbricata retained category 1 status in revised plant notices published 
on September 27, 1985 (50 FR 39526), February 21, 1990 (55 FR 6184), 
and September 30, 1993 (58 FR 51144).
    A proposal to list Arctostaphylos imbricata as threatened and 
Lessingia germanorum as endangered was published in the Federal 
Register on October 4, 1994 (59 FR 50550). This notice of withdrawal of 
the proposal to list A. imbricata is published concurrently in the 
Federal Register with the final rule listing L. germanorum as 
endangered in order to resolve the listing status of both species. 
Processing the final listing decisions on these two species follows the 
Service's listing priority guidance published in the Federal Register 
on December 5, 1996 (61 FR 64475).

Summary of Comments and Recommendations

    In the October 4, 1994, proposed rule and associated notifications, 
all interested parties were requested to submit factual reports or 
information

[[Page 33389]]

that would contribute to the development of a final decision document. 
Appropriate Federal and State agencies, county and city governments, 
scientific organizations, and other interested parties were contacted 
and requested to comment. In accordance with Service policy published 
on July 1, 1994 (59 FR 34270), the Service solicited comments from 
three appropriate and independent specialists regarding pertinent 
scientific or commercial data and assumptions relating to the proposed 
rule. A newspaper notice of the proposed rule was published in the San 
Francisco Chronicle on October 19, 1994, which invited general public 
comment. A 60-day comment period closed on December 4, 1994.
    The Service received eight letters of comment. No requests for 
public hearings were received. Because the proposed rule included both 
Arctostaphylos imbricata and Lessingia germanorum, only comments 
pertaining to A. imbricata are discussed here. Comments and issues 
pertaining to L. germanorum are discussed in a separate Federal 
Register notice published concurrently with this notice.
    Of the eight people who submitted comments, three were neutral and 
four supported the listing of Arctostaphylos imbricata. The eighth 
respondent opposed the listing of A. imbricata on the grounds that 
listing was premature at the time and recommended that it be retained 
as a candidate species. As previously indicated, the listing proposal 
for A. imbricata is being withdrawn in this notice. A candidate is a 
species for which the Service has on file sufficient information on the 
status and threats to the species to support issuance of a listing 
proposal. Therefore, upon the withdrawal of the proposal to list, A. 
imbricata cannot be maintained as a candidate.
    One commenter indicated that designation of critical habitat would 
aid in protection of rare plants. Because the proposed rule for 
Arctostaphylos imbricata is being withdrawn, this issue is moot with 
respect to this species. Another commenter suggested that the effects 
of microwave facilities on San Bruno Mountain might pose a threat to 
the species. The Service is not aware of any data to support this 
contention and no evidence was provided by the commenter.
    The combined threats of senescence (growing old, dying) of plants 
and lack of reproduction due to the prolonged absence of fire described 
in the proposed rule were considered by another commenter to be 
unsubstantial. After reviewing the available information, the Service 
concurs. More detail on this issue is provided in the discussion of 
Factor E in the ``Summary of Factors Affecting the Species'' section 
below.
    Only one of the three independent and appropriate specialists 
provided comments on the proposal to list Arctostaphylos imbricata. 
This reviewer concurred with all of the comments made in the proposed 
rule concerning the status, threats, and potential threats to the 
species and supported listing as proposed. The reasons for the 
Service's decision to withdraw its proposal to list A. imbricata, in 
opposition to this specialist's recommendation, are explained in the 
following section.

Summary of Factors Affecting the Species

    Section 4(a)(1) of the Act requires the Service to consider five 
factors when determining whether to list a species as threatened or 
endangered. These factors, and their application to the Service's 
decision to withdraw the proposal to list Arctostaphylos imbricata 
Eastw. (San Bruno Mountain manzanita), are as follows:
    A. The present or threatened destruction, modification, or 
curtailment of its habitat or range. No threats to Arctostaphylos 
imbricata were identified under this factor in the proposed rule, nor 
were any such threats identified by commenters on the rule. None of the 
colonies are threatened by development permitted under the San Bruno 
Mountain HCP. The Service believes that no threats exist to the 
species' habitat or range.
    B. Overutilization for commercial, recreational, scientific, or 
educational purposes. The proposed rule cited overutilization for 
horticultural purposes as a potential threat to Arctostaphylos 
imbricata. In 1991, cuttings were taken from plants located at 
Kamchatka Point on San Bruno Mountain. The remnant surviving portions 
of the plants showed evidence that the clippings were performed with 
horticultural expertise (Doug Heisinger, Park Ranger, San Mateo County 
Park, pers. comm. 1993). Some A. imbricata individuals being sold at 
local plant sales may have originated from clippings from the natural 
population (Paul Reeberg, pers. comm. 1993). The Service now concludes 
that, although such actions are inappropriate and illegal (under both 
the California Endangered Species Act and the California Native Plant 
Protection Act), infrequent pruning does not currently constitute a 
significant threat to the survival of the species.
    C. Disease or predation. No known threats from disease or predation 
were identified in the proposed rule. The Service has no new 
information on threats from these factors.
    D. The inadequacy of existing regulatory mechanisms. The proposed 
rule stated that Arctostaphylos imbricata derived limited protection 
from the San Bruno Mountain HCP, but that no species-specific 
management actions for A. imbricata are identified in the HCP and none 
have been implemented. After publication of the proposed rule, the HCP 
Trustees informed the Service that the San Bruno Mountain HCP provides 
for monitoring and management of populations of all rare plants 
occurring on the mountain including A. imbricata. Moreover, the HCP 
Trustees have agreed and committed to an annual budget for rare plant 
monitoring and management. Any specific management activities 
recommended, such as controlled burning (see Factor E below), will be 
carried out under the HCP. Present management for A. imbricata includes 
alien plant control. The Trustees have also expressed a willingness to 
meet and work with Service biologists to identify and implement any 
specific management actions necessary for the conservation of the 
species (V. Harris, in litt. 1996).
    Arctostaphylos imbricata is listed as endangered under the 
California Endangered Species Act (Chapter 1.5 section 2050 et seq. of 
the California Fish and Game Code and Title 14 California Code of 
Regulations 670.2). The proposed rule stated that, although both the 
California Endangered Species Act and the California Native Plant 
Protection Act prohibit the ``take'' of State-listed plants (California 
Endangered Species Act, Chapter 1.5 section 2080 and California Native 
Plant Protection Act, Chapter 10 section 1908), State law exempts the 
taking of such plants via habitat modification or land use changes by 
the owner provided notification requirements are satisfied. The Service 
concluded that this exemption renders State law inadequate to protect 
A. imbricata from extinction. The Service believes that the inadequacy 
of State law in protecting A. imbricata is no longer an issue because 
protection of the species is provided by the San Bruno Mountain HCP.
    E. Other natural or manmade factors affecting its continued 
existence. The Service indicated in the proposed rule that 
Arctostaphylos imbricata is a fire-adapted plant that, following a 
fire, regenerates entirely from seed and does not resprout from a basal 
burl. Keeley (1977) labeled plants employing this

[[Page 33390]]

type of post-fire reproductive strategy ``obligate-seeders.'' The 
Service also implied in the proposed rule that fire, which can remove 
competing vegetation and counter mechanisms that prevent seed 
germination (e.g., hormones, impervious seed coat), is necessary for 
the maintenance of A. imbricata because sexual reproduction by seed is 
important to the maintenance of genetic diversity. Although germination 
of its seed bank (seeds accumulated in the soil and canopy of mature 
shrubs) is triggered mainly by fire, occasional germination and 
establishment of A. imbricata does occur without the aid of fire (R. 
Gankin, in litt., 1994). Moreover, A. imbricata can spread vegetatively 
and reportedly is spreading on San Bruno Mountain (R. Gankin, in litt., 
1994). Thus, fire is not necessary for maintenance of the species.
    The Service asserted in the proposed rule that if the amount of 
time between fires were too long, Arctostaphylos imbricata would have 
little opportunity to reproduce sexually and individuals could become 
senescent. However, Keeley (1977) argued that the reproductive strategy 
of obligate-seeders such as the non-sprouting manzanita species is an 
adaptation to a long-interval fire cycle. Obligate-seeders tend to 
occur in less fire-prone areas, like San Bruno Mountain which is often 
shrouded in fog during the summer (D. Schooley, Bay Area Land Watch, in 
litt., 1994), that generally burn more intensely when fires do occur 
(Keeley 1977). Consequently, A. imbricata and other obligate-seeders 
``are resilient to very long intervals [between fires] and successful 
seedling recruitment is observed after fires in stands which may exceed 
100 years of age'' (Keeley et al. 1988). In addition, fires burned 
colonies of A. imbricata on San Bruno Mountain in 1964 and in the late 
1980's. Even though all of the individuals in the colony which burned 
in the 1980's were killed, significant regeneration did take place (R. 
Gankin, in litt., 1994). Also, both regeneration from seed and 
spreading by layering has occurred in the colony which burned in 1964 
(D. Schooley, in litt., 1994). For these reasons, the Service concludes 
that the prolonged absence of fire does not threaten A. imbricata now 
and will not in the foreseeable future.
    The Service also stated in the proposed rule that a reduction in 
fire frequency could pose a threat to the species because periodic 
fires reduce competition and shading by other plant species. On San 
Bruno Mountain, Arctostaphylos imbricata grows on rocky exposed areas 
such as open ridges. On such sites, the lack of soil development 
precludes significant establishment of other plant species; the species 
most likely to pose a threat through overtopping and consequent 
shading, Ceanothus thrysiflorus, is a short-lived species that does not 
do well on such undeveloped soils (R. Gankin, in litt., 1994). The 
Service now concludes, on the basis of the foregoing evidence, that the 
prolonged absence of fire is not likely to result in significant 
establishment of other plant species and that therefore competition 
from (including shading by) other plant species does not pose a 
significant threat to the survival of A. imbricata.
    Frequent fire, that is fire recurring within a short period of time 
(fewer than 15 years), can result in local extinctions (Zedler et al. 
1983 in Keeley and Keeley 1988). As discussed above and in the proposed 
rule, on San Bruno Mountain Arctostaphylos imbricata grows on rocky 
exposed areas such as open ridges. Because such open sites lack 
sufficient fine fuels (i.e., dried grass and herbs) to sustain fire or 
carry fire from adjoining, more densely vegetated habitat, the Service 
concludes that fire is unlikely to occur frequently in A. imbricata 
habitat and that, therefore, frequent fire is not a significant threat 
to the species.
    The Service has carefully assessed the best scientific and 
commercial information available regarding the past, present, and 
future threats faced by Arctostaphylos imbricata in determining to 
withdraw the proposed rule to list the species as threatened. The 
Service has determined that implementation of the San Bruno Mountain 
HCP, which includes monitoring and management of A. imbricata, 
sufficiently removes the threats to the species and provides for its 
conservation. Furthermore, the Service has determined that the threats 
identified in the proposed rule pertaining to fire frequency and 
overutilization for horticultural purposes are not likely to pose a 
significant risk to the survival of A. imbricata.
    Author: The primary author of this document is Diane Windham, 
Sacramento Field Office (see ADDRESSES section).

    Authority: The authority for this action is section 
4(b)(6)(B)(ii) of the Endangered Species Act of 1973, as amended (16 
U.S.C. 1531 et seq).

    Dated: April 8, 1997.
John G. Rogers,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 97-15926 Filed 6-18-97; 8:45 am]
BILLING CODE 4310-55-P