Endangered and Threatened Wildlife and Plants; Withdrawal of Proposed Rule to List Nolina interrata (Dehesa beargrass) as Threatened

SUMMARY: The U. S. Fish and Wildlife Service (Service) withdraws the

proposal to list Nolina interrata (Dehesa beargrass) as threatened

under the Endangered Species Act of 1973, as amended (Act). This plant

species is one of four chaparral species that were proposed for listing

on October 2, 1995 (60 FR 51433). The Service finds that the

information now available, as discussed below, justifies withdrawal of

the proposed listing of this species. The California Department of Fish

and Game and The Nature Conservancy have management prescriptions that

will significantly reduce the threats to the known occurrences of

Nolina interrata. In addition, provisions of the Multiple Species

Conservation Program (MSCP), as implemented by the County of San Diego

through the County's Subarea Plan to the MSCP, and the provisions of

the County's Biological Mitigation Ordinance adopted on October 22,

1997, require avoidance of ``narrow endemic plants'' (in the Metro-

Lakeside-Jamul segment of the San Diego County Subarea Plan), including

N. interrata. When complete avoidance is not possible, encroachment is

limited and requires mitigation. These measures, many of which have

been adopted since the proposal to list, will significantly reduce

threats to the remaining populations of this species. Based on this

information, the Service concludes that listing N. interrata is not

warranted. The other plant species, Mexican flannelbush

(Fremontodendron mexicanum), Nevin's barberry (Berberis nevinii), and

Vail Lake ceanothus (Ceanothus ophiochilus), which were proposed for

listing with N. interrata (60 FR 51433), are the subjects of a final

listing action in this same Federal Register part, to be published on

the same day as this withdrawal.

ADDRESSES: The complete file for this rule is available for public

inspection, by appointment, during normal business hours at the U.S.

Fish and Wildlife Service, Carlsbad Field Office, 2730 Loker Avenue

West, Carlsbad, California 92008.

FOR FURTHER INFORMATION CONTACT: Elizabeth Stevens, Deputy Field

Supervisor, at the above address (telephone 760/431-9440; facsimile

760/431-9624).

SUPPLEMENTARY INFORMATION:

Background

On October 2, 1995, the Service published in the Federal Register

(60 FR 51443) a proposal to list four chaparral plants from

southwestern California and northwestern Estado de Baja California,

Mexico, as endangered or threatened; that proposed rule included Nolina

interrata (Dehesa beargrass).

Nolina interrata occurs in restricted and localized populations

from the interior foothills of San Diego County to northwestern Baja

California, Mexico. Most populations of N. interrata are situated in

relatively rugged terrain dominated by chaparral, which is often

associated with nutrient-poor soils and cool wet winters and hot dry

summers. Nolina interrata is often found in association with specific

soil types.

Chaparral occurs on many different soil types, but Nolina interrata

typically occurs in clay soils derived from gabbro or metavolcanic

bedrock (Oberbauer 1991, California Natural Diversity Data Base (CNDDB)

1997). Clay soils have unique physical and chemical properties that

contribute to the disproportionally large number of rare plants found

on this substrate, as compared to other soil types (Oberbauer 1991).

For these reasons, clay soils are an important contributor to plant

diversity in the San Diego County region.

Many chaparral species are adapted to periodic wildfires. In some

species, only seeds survive fires and may, in fact, require fire to

germinate (Keeley 1991). Other plants reproduce vegetatively by

sprouting from the burned stumps. Fires that occur too frequently can

burn young or resprouting shrubs before they become reproductively

mature and, thus, deplete or exhaust the seed bank (Zedler et al.

1983). Sustained fire prevention can result in senescent (old) plant

communities that may not survive the eventual and unpredictable fires

that do occur. Within these senescent (extremely old) chaparral

communities, high fuel loads of woody plant material build up in the

absence of fire; this often results in unnatural, very hot fires

causing reproductive failure for some species through killing of stumps

and seed banks. It is likely that senescence of chaparral communities

can cause a reduction in range and number of certain plant species,

including Nolina interrata. This species may repopulate historically

occupied areas if a natural fire regime is restored.

Nolina interrata, a member of the lily family (Liliaceae), was

described by Howard S. Gentry (1946) based on a collection he made in

1945 near Dehesa School in San Diego County, California. Gentry's

treatment is followed by Munz (1974) and Dice (1993). The most recent

taxonomic treatment of the genus (Dice 1988) also found Nolina

interrata to be distinctive. Beauchamp (1986), in his flora of San

Diego County, listed Nolina interrata as conspecific (of the same

species) with Nolina parryi.

Nolina interrata is a dioecious (separate male and female plants)

perennial forming clusters of rosettes from underground rhizomatous

platforms (rootlike horizontal stems). The glaucous (white powdery)

leaves are 10-45 per rosette. The paniculate flower stalks are 0.5-1.6

meters (m) (1.6-5 feet (ft)) tall and up to 16 millimeters (mm) (0.6

inch (in)) in diameter at the base. The flowers are 2-4 mm (0.1-0.2 in)

wide with whitish perianth parts. Nolina interrata is distinguished

from the other Nolina species that occur in California by its lack of

aerial stems, rosettes with 45 or fewer finely serrate leaves, and

flower stalks under 1.6 m (5 ft) tall. It can be distinguished from

Yucca species by its lack of a rigid spinose (spiny) leaf tip and

leaves with shredding margins.

Nolina interrata grows in the chaparral community and is commonly

associated with Adenostoma fasciculatum (chamise), Helianthemum

scoparium (peak rush-rose), Salvia clevelandii (Cleveland sage), and

Tetracoccus dioicus (San Diego button bush). Nolina interrata is often

associated with other rare plants such as Senecio ganderi (Gander's

butterweed), Acanthomintha ilicifolia (San Diego thornmint), Monardella

hypoleuca ssp. lanata (felt-leaved monardella), and Fritillaria biflora

(chocolate lily) (Oberbauer 1979). The association of N. interrata with

these species reflects the distribution of clay soils formed from

gabbro soils in the region (Oberbauer 1979, 1991; Beauchamp 1986).

Nolina interrata does not flower every year and reproduces primarily

asexually, which may compensate for its lack of consistent flowering.

This species may require fire or other disturbance to induce flowering.

The known numbers of Nolina interrata totals about 9,000 plants.

There are nine populations of N. interrata in San Diego County, all

within a 15.6 square-kilometer (km2) (6-

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square-mile (mi2)) area in the Dehesa Valley, immediately

east of El Cajon, California. There are no records of extirpated

populations. About two-thirds of all populations, and 90-100 percent of

all major populations, are protected on reserve lands owned and managed

by The Nature Conservancy (TNC) at McGinty Mountain and by the

California Department of Fish and Game (CDFG) at Sycuan Peak. The

protection afforded by the establishment of the Sycuan Ecological

Preserve occurred subsequent to the proposal to list N. interrata. The

remaining few occurrences are small and are on private lands (Oberbauer

1979, CNDDB 1997).

Nolina interrata is known from three localities in Baja California

and ranges as far south as Ensenada (Rancho de la Cruz) in Baja

California, Mexico (Jim Dice, California Department of Fish and Game,

pers. comm. 1997). One population is about 16 km (10 mi) northeast of

La Mision. Both of these disjunct Mexican populations have fewer than

25 individuals each. Another population has recently been discovered in

Mexico closer to the United States border, and it appears to be of

comparable size (J. Dice, pers. comm. 1997).

Summary of Comments and Recommendations

In the October 2, 1995, proposed rule (60 FR 51443) and associated

notifications, all interested parties were requested to submit factual

reports or information that might contribute to the development of a

final rule. The 45-day comment period closed on November 16, 1995.

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 peer-review policy

published on July 1, 1994 (59 FR 34270), three appropriate and

independent specialists were solicited to review pertinent scientific

or commercial data and assumptions relating to the proposed rule. No

responses were received from the solicited peer reviewers. Individual

newspaper notices of the proposed rule were published in the San Diego

Union-Tribune and the Riverside Press-Enterprise on October 20, 1995. A

public hearing was requested but precluded by severe funding

constraints between November 1995 and April 1996. The requesting party

subsequently submitted written comments to the Service during the

comment period. A letter was sent to the party on June 4, 1997,

inquiring what their current wishes were relative to their previous

request for a public hearing. No response was received.

During the comment period, the Service received four letters

concerning the proposed rule, including one from a Federal agency, one

from a State agency, and two from individuals or groups. One respondent

expressed support for the listing proposal, one opposed it, and two

were neutral. Because the proposed rule included four plant species,

only the one comment specific to Nolina interrata is discussed here.

Comments not specific to this species and general comments pertaining

to the proposed rule are discussed in a separate final rule to list

Fremontodendron mexicanum, Berberis nevinii and Ceanothus ophiochilus

published in this same Federal Register part (see SUMMARY above). One

comment relevant to the proposed listing of Nolina interrata and the

Service's response is summarized below:

Issue 1: One commenter requested that the Service use the

protections afforded by the Multiple Species Conservation Plan (MSCP)

to minimize habitat fragmentation.

Service Response: The County of San Diego received an incidental

take permit from the Service in March 1998, based on the MSCP as

implemented through the County's Subarea Plan, including the Biological

Mitigation Ordinance. The County adopted the Biological Mitigation

Ordinance on October 22, 1997, subsequent to the proposal to list

Nolina interrata. The conservation measures described in the MSCP and

the recently adopted Biological Mitigation Ordinance are expected to

minimize habitat fragmentation of areas occupied and potentially

occupied by N. interrata. This species is covered by the MSCP and 100

percent of the McGinty Mountain population, 90-100 percent of the

Sycuan Peak, and 80-100 percent of the Dehesa Peak population will be

conserved. This represents 90-100 percent of all major populations.

Protection on the Sycuan Ecological Preserve was guaranteed subsequent

to the proposal to list N. interrata. These protections on public and

private lands are the primary reasons for the Service's decision to

withdraw the proposal to list N. interrata as an endangered species.

Summary of Factors Affecting the Species

The Service must consider five factors described in section 4(a)(1)

of the Act when determining whether to list a species. These factors

and their application to the Service's decision to withdraw the

proposal to list Nolina interrata H. Gentry (Dehesa beargrass) are as

follows:

A. The Present or Threatened Destruction, Modification, or Curtailment

of Their Habitat or Range

Urbanization and associated habitat loss and further habitat

fragmentation are no longer significant threats to Nolina interrata.

Sixty-seven percent (35 records) of the MSCP point occurrences of N.

interrata are on reserve lands owned and managed by the California

Department of Fish and Game at Sycuan Peak and on lands owned and

managed by The Nature Conservancy at McGinty Mountain. A point

occurrence is defined as a single record in the MSCP database contained

at the Carlsbad Field Office. The broader protection afforded to this

species by the increased size of the Sycuan Ecological Preserve

occurred after N. interrata was proposed for listing. Since the

proposed rule was published, the California Department of Fish and Game

has acquired nearly all of the necessary parcels to complete this

preserve (J. Dice, pers. comm. 1997). The remaining 33 percent (17

records) will be protected under provisions of the MSCP that require

avoidance of narrow endemic species to the maximum extent possible. The

County's Biological Mitigation Ordinance requires encroachment to be

limited to 20 percent of the population on site for impacts that cannot

be avoided. Nolina interrata is covered by the MSCP based on

conservation of 100 percent of the McGinty Mountain population, 90-100

percent of the Sycuan Peak, and 80-100 percent of the Dehesa Peak

population under this plan (City of San Diego 1997).

B. Overutilization for Commercial, Recreational, Scientific or

Educational Purposes

Access to many Nolina interrata populations is limited by private

property boundaries or rugged terrain. Nolina interrata has been

collected for specimens, but this activity has mainly involved plants

salvaged from road cuts, eroded cuts, or bulldozed areas (Oberbauer

1979).

C. Disease or Predation

Disease and predation are not known to be factors adversely

affecting Nolina interrata.

D. The Inadequacy of Existing Regulatory Mechanisms

The Service evaluated existing Federal, State, and local

regulations prior to preparing the proposed rule that included Nolina

interrata. The Service found evidence the existing regulatory

mechanisms were, overall, inadequate at that time. These regulatory

mechanisms included: (1) Listing under the

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California Endangered Species Act (CESA); (2) the California

Environmental Quality Act (CEQA) and the National Environmental Policy

Act (NEPA); (3) conservation provisions under section 404 of the

Federal Clean Water Act and Section 1603 of the California Fish and

Game Code; (4) occurrence with other species protected by the Federal

Endangered Species Act; (5) local laws and regulations; (6) land

acquisition and management by Federal, State, or local agencies, or by

private groups and organizations; and (7) adequate consideration in

State or regional conservation planning efforts such as the Multiple

Species Conservation Plan (MSCP) of the Natural Community Conservation

Planning (NCCP) Program, and other multispecies efforts.

The adverse impacts of various development projects on Nolina

interrata, because of its rare and localized nature, will be considered

by Federal, State, and local planning agencies under CEQA and NEPA. The

management activities implemented or proposed by the California

Department of Fish and Game on the Sycuan Ecological Preserve and The

Nature Conservancy at McGinty Mountain, as well as measures included in

the MSCP and the County's Biological Mitigation Ordinance relating to

narrow endemic plants (County of San Diego 1997), should assure

adequate protection of Nolina interrata.

E. Other Natural or Manmade Factors Affecting Their Continued Existence

Nolina interrata depends on natural fire patterns; alteration of

natural fire periodicity, season, and intensity may have various

adverse effects on this species. Fire suppression measures are

intensified in undeveloped areas near population centers. The natural

period between fires in these areas may be altered. Fire suppression

activities may also affect the vegetation. High fire frequencies

prevent young plants from reaching reproductive maturity and will

result in population declines or extirpation once the underground seed

bank has been depleted (Zedler et al. 1983). In other cases, the

reduced frequency of fire due to fire suppression programs can

adversely affect the viability of plant populations by reducing genetic

diversity.

Nolina interrata flowers profusely after fires. Plants also

reproduce vegetatively from underground stems. Occurrences that are

entirely female require pollen from disjunct male plants to fertilize

the flowers and produce viable seeds. Plants in disjunct populations

may not flower simultaneously, because flowering is, in part, dependent

upon site-specific fire history (Dice 1988). Appropriately timed

controlled burns may be necessary to maintain population vigor. The

threats to this species from changes in natural fire frequencies will

be reduced due to the development and implementation of management

plans. Management plans, which include considerations for the fire

ecology of this species, are being developed for the lands inhabited by

N. interrata on Sycuan Ecological Reserve and McGinty Peak (J. Dice,

pers. comm. 1997).

Because Nolina interrata is known from small populations with

relatively few individuals, it is vulnerable to extinction due to

random events, such as hot, slow-burning fires. Genetic variability

also may be reduced in small populations of limited distribution

(Barrett and Kohn 1991). One of the Dehesa Valley populations of Nolina

interrata is considered to be a single female clone (J. Dice, pers.

comm. 1997). A single event or series of events can reduce a species

below recoverable numbers. Proactive recovery efforts to lessen the

threat of such random events typically involve the establishment of

reserves that permanently protect and manage populations of the species

of concern. The management and protection of public and private lands

inhabited by N. interrata on Sycuan Ecological Preserve and McGinty

Mountain will significantly reduce the threats to this species from

random events.

The Service has carefully assessed the best scientific and

commercial information available and has determined that listing Nolina

interrata as threatened is no longer warranted. Since the proposed rule

for listing N. interrata was published, the California Department of

Fish and Game acquired the majority of the lands inhabited by N.

interrata on Sycuan Peak Ecological Preserve. The Nature Conservancy

owns and manages lands at McGinty Mountain supporting this species.

Provisions set forth in the MSCP and the County's Biological Mitigation

Ordinance relating to narrow endemic plants will afford significant

protection to the locations known to contain Nolina interrata. Other

factors cited in the proposed rule, including fire management

practices, over collection, and random natural events, are now of

insufficient magnitude to warrant listing of the species in the absence

of any significant threat from other factors.

References Cited

A complete list of all references cited in this withdrawal notice

are available upon request from the U.S. Fish and Wildlife Service,

Carlsbad Field Office (see ADDRESSES above).

Authors: The primary authors of this withdrawal notice are Dr. Gary

D. Wallace and Christopher D. Nagano, Carlsbad 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: September 29, 1998.

Jamie Rappaport Clark,

Director, Fish and Wildlife Service.

[FR Doc. 98-26860 Filed 10-9-98; 8:45 am]

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