(DRAFT) - Taxonomy
Species FERN, SHIELD, ALEUTIAN
Species Id ESIS857001
Date 13 MAR 96

TAXONOMY

NAME - FERN, SHIELD, ALEUTIAN

OTHER COMMON NAMES - FERN, SHIELD, ALEUTIAN; FERN, SHIELD; FERN, HOLLY and ALEUTIAN

ELEMENT CODE -

CATEGORY - Fern/F-Ally

PHYLUM AND SUBPHYLUM - POLYPODIOPHYTA,

CLASS AND SUBCLASS - FILICOPSIDA,

ORDER AND SUBORDER - FILICALES,

FAMILY AND SUBFAMILY - POLYPODIACEAE,

GENUS AND SUBGENUS - POLYSTICHUM,

SPECIES AND SSP - ALEUTICUM,

SCIENTIFIC NAME - POLYSTICHUM ALEUTICUM

AUTHORITY -

TAXONOMY REFERENCES -

COMMENTS ON TAXONOMY -
Aleutian Shield Fern

Polystichum aleuticum C. Christens. in Hulten

KINGDOM: Plant GROUP: Fern or fern ally

DIVISION: Polypodiophyta CLASS: Filicopsida
ORDER: Filicales FAMILY: Polypodiaceae

Non-technical Description (derived from 20,23,24,25,30). Plants
small and erect, about six inches tall, usually solitary,
fibrous-rooted with a thickened base bearing numerous chestnut-brown
leaf base remnants. Leaves (fronds) present only during growing
season, light, dark or olive green in color, gradually tapering at
the base and tip; blades once divided into slightly overlapping
segments; the segments ovate, slightly bulging at base, incised with
short bristle tips. Scales sparingly distributed along main leaf axis
and especially on under-surface of leaf segments, delicate,
straw-colored, lance-shaped up to 3-4 mm long. Spore masses
aggregated into 6-8 patches forming two rows along under-surface of
leaf segments.
Technical Description (derived from 30). Plants solitary,
occasionally clumped, fibrous-rooted, erect to 10-18 cm tall, bearing
numerous (10) - 30-50 - (or more) elaminate, persistent
Taxonomy - 1 (DRAFT) - Taxonomy
Species FERN, SHIELD, ALEUTIAN
Species Id ESIS857001
Date 13 MAR 96

chestnut-brown stipe remnants. Leaves herbaceous, produced annually
7-15 cm long, pinnately compound; laminae linear, 3/4 or greater the
leaf length, to 1.5 cm wide, tapering at base and tip. Pinna pairs
(15) - 18-22 - (25), opposite to subopposite at base, alternate
above, subalternate and pinnatifid at tip, sessile and disposed
perpendicular to axis, 7 mm long x 4.5 mm wide at mid-lamina,
gradually reduced at base and tip, not or barely touching below
midleaf, succubously overlapping above, subsymmetrically ovate,
incised-lobate to/and irregularly serrate with mucronate, subhyaline
tips. Stipe and rachis scales crowded in vernation, tufted at pinna
attachment, scattered along rachis in expanded fronds, paleaceous,
brunneo-stramineous, lanceolate to 3 - (5) mm long, weakly to
conspicuously lacinate at base, sparingly and occasionally retrorsely
denticulate along margins; pinna scales somewhat reduced in size,
otherwise similar, conspicuous on the soral surface, absent or rare
on the non-soral surface except at frond tip. Sori normally 6 - 8 -
(10) per pinna in two median rows. Indusia persistent, some confluent
to barely overlapping, irregularly peltiform, excentrically attached;
margins erose. Spores 64 per sporangium, (41) - 47-49 - (52) um
greatest exospore diameter, granulose with perine weakly alveolate
of low crests and papillae; maturing (? July) after mid-August.
Classification and Nomenclature. The Aleutian shield fern (holly
fern) Polystichum aleuticum C. Christens. has no species synonyms in
scientific nomenclature (21). The complete author citation should
read C. Chr. in Hulten (17) giving credit to the original description
prepared by Christensen albeit published by Hulten. Common names
referring to this species include: Shield Fern (unnamed) (09); Shield
Fern (Holly Fern) Aleutian (10,11,12); Aleutian Shield-Fern
(13,14,24,25,29,33); and Aleutian Holly-Fern (22,24,25,33).
An acceptable classification above species level follows Bold
et al. (06): Division Pteridophyta (Ferns); Class Filicopsida; Order
Filicales; Family Polypodiaceae (04,08,09,10,11,12,13,14,33). Other
authorities have placed this species within the fern families
Aspidiaceae (20), Aspleniaceae (21), and Dryopteridaceae (22).
Various authorities have treated this species through technical
descriptions (Christensen in 17,22,23,33), short diagnoses (20,32),
non-technical descriptions (23,24,25), and taxonomic comments
(07,18,28).
Type Specimens. Specimens of the original collection (1932)
include the holotype at the Swedish Museum of Natural History,
Stockholm (S) (32); isotypes at the California Academy of Sciences,
San Francisco (CAS) (32); Dudley Herbarium of Stanford (DS) (32) at
(CAS); and the Smithsonian Institution, Washington, D.C. (US) (32).
Photographs of the type and their location have been catalogued
by Lipkin (23) citing: 1) U.S. National Herbarium Vascular Plant Type
Collection, microfiche #1027, column 4, row 11 (isotype); 2)
University of Michigan, negative #1306; and 3) Washington State
University, negatives #273437, #273438. Additional photographs appear
in Hulten (17), presumably the holotype (S); and Lellinger (22)
representing material collected on Adak in 1975.
Additional Specimens. Specimens prepared from collections
in 1975 on Adak (28) are deposited in herbaria of the University of
Alaska, Fairbanks (ALA), the University of Tennessee, Knoxville
Taxonomy - 2 (DRAFT) - Taxonomy
Species FERN, SHIELD, ALEUTIAN
Species Id ESIS857001
Date 13 MAR 96

(TENN), and the University of Oregon, Eugene (ORE). A single specimen
collected in 1987 on Adak (29) is deposited at the Smithsonian
Institution (US).
Line Drawings. Line drawn images of habit profile are presented
by Hulten (20). Hulten's figure has been reproduced and enlarged by
Murray (24). An original illustration including pinna detail recently
has been produced by Murray and Lipkin (25).
Current Status. Fish and Wildlife Service, Interior, has
recently issued (1988) a Final Rule determining endangered status for
Polystichum aleuticum (14) effective March 18, 1988.

Taxonomy - 3 (DRAFT) - Status
Species FERN, SHIELD, ALEUTIAN
Species Id ESIS857001
Date 13 MAR 96

STATUS

Coded Status

E: Federal Endangered

Non-consumptive recreational

COMMENTS ON STATUS -
U.S. STATUSES AND LAWS:
The Aleutian shield fern (Polystichum aleuticum) has been
designated an Endangered species pursuant to the Endangered Species
Act of 1973 (50 CFR 17.12; P.L. 93-205, 87 Stat. 884; 16 U.S.C.
1531-1540), as amended. The species has this status wherever found
including the State of Alaska.
Removal and reduction to possession of any Federally listed plant
from an area under Federal jurisdiction is unlawful (50 CFR 17.61 and
17.71).
This species is protected by the Lacey Act (P.L. 97-79, as
amended; 16 U.S.C. 3371 et seq.) which makes it unlawful to possess
any wild plant (including roots, seeds, and other parts) within U.S.
territorial or special maritime jurisdiction (as defined in 18 U.S.C.
7); or to import, export, transport, sell, receive, acquire, or
purchase in interstate or foreign commerce any wild plant (including
roots, seeds, and other parts) taken, possessed, transported, or sold
in violation of any State law or regulation. It is also unlawful to
import, export, transport, sell, receive, acquire, or purchase any
wild plant (including roots, seeds, and other parts) taken or
possessed in violation of any U.S. law, treaty, or regulation or in
violation of Indian tribal law.

RESPONSIBLE FEDERAL AGENCIES:

USFWS -Responsible for the management/recovery, listing, and
law enforcement/protection of this species.
BIA -Responsible for the law enforcement/protection of this
species with applicable State and Federal laws on
public lands under their control. Also responsible
for management/recovery on Bureau of Indian Affairs
lands.
DOD -Responsible for the law enforcement/protection of this
species with applicable State and Federal laws on
public land under their control. Also responsible for
management/recovery on Department of Defense lands.

All Federal agencies have responsibility to ensure that any
action authorized, funded, or carried out by that agency is not likely
to jeopardize the continued existence of the species or result in the
destruction or adverse modification of Critical Habitat (50 CFR 402),
and to utilize their authorities to carry out programs for the
conservation of the species.
Status - 1 (DRAFT) - Status
Species FERN, SHIELD, ALEUTIAN
Species Id ESIS857001
Date 13 MAR 96

STATE STATUSES AND LAWS:

STATE: Alaska
DESIGNATED STATUS: None.

INTERNATIONAL STATUSES, TREATIES, AND AGREEMENTS:
CITES I.

ECONOMIC STATUSES:
There are no known cultural, commercial, or medicinal values
associated with the species; however, it is of significant scientific
value. The species is likely a relict of tertiary flora and thus is
of great value in studies of island biogeography and the paleoecology
of Beringia (see Lipkin (23)). The species is also of recreational
value to amateur botantists. No negative values have been associated
with this species.

75/01/09:40 FR 27823/ - Petition acceptance
76/06/16:41 FR 24523/ - Proposed rule/endangerd
78/04/26:43 FR 17909/ - Summary of comments
79/12/10:44 FR 70796/ - Proposal withdrawl
80/12/15:45 FR 82480/ - Notice of review
85/09/27:50 FR 39526/ - Notice of review
87/04/24:52 FR 13729/13732 - Proposed rule/endangered
88/02/17:53 FR 04626/04630 - Final rule/endangered

Status - 2 HABITAT ASSOCIATIONS

HABITAT - TERRESTRIAL
TERRESTRIAL

LAND USE -
Tundra Land: Shrub Brush
Tundra Land: Herbaceous
Tundra Land: Mixed

COMMENTS ON HABITAT ASSOCIATIONS -
Habitat details of the Aleutian shield fern are known only
from two populations discovered on Adak Island in 1975 and 1987.
Whereas little attention was paid to site characters of the 1975
population, field notes and observations were especially recorded
after discovery of the 1987 population (31). Nothing can be said
of the Atka collection (1932) because no data were recorded by the
collector as to site location or habitat except for "very rare" (23).
The index of Forest/Rangeland Associations (this document) that
most closely references the general aspect of shield fern habitat
are: Aleutian alpine tundra (code 53 Empetrum - Vaccinium and
barren).
There are no existing nor expected agricultural practices that
will modify or displace the fern habitat.
The species is not associated with any National Wetland
Inventory types.
The fern's habitat consists of exposed, weathered rock outcrops
with rooting substrate confined to fissures, crevices, and thinly
mantled horizontal ledges (section 5, this document). The habitat is
apparently unique, restricted to rare combinations of aspect,
exposure, substrate stability, and moisture (31). There is no defined
composition of vegetation as per Aleutian tundra classifications
proposed by Hulten (19), Skacklette (27), or Amundsen (02). Broadly
circumscribed units of vegetation in proximity to shield fern habitat
correspond to Anderson et al. (03) categories of Mixed Tundra
consisting of low profile Shrub and Brush Tundra, upland Herbaceous
Tundra, and Bare Ground Tundra, where features of surface relief
(e.g. angle of slope, aspect, thickness and stability of soil mantle,
and soil moisture of rhizosphere) dictate pattern and size of plant
community patches (31).
The 1987 population is confined within an area of approximately
100 sq. ft. on the east face of the north arm of Mt. Reed at 1600
feet elevation (29). That of the 1975 population was growing in a
linear rock crease approximately 10 feet long at a lower (unmeasured)
estimated elevation of 1300 feet (31). Both populations occurred
similarly on near vertical, tilted rocky outcrops that are heavily
fractured with crisp lines of vertical and horizontal cleavages.
The sites are totally exposed to conditions of climatic weathering,
mostly fog-enshrouded during the summer months. Site conditions
during the winter months are undocumented, but the dormant
perennating shoot crowns probably experience alternating periods of
snow or ice cover, wind abrasion, and higher insolation. Soil
accumulations in the rock crevices are the rooting medium, consisting
of dark, extremely fine-grained particles. Moisture does not appear
to be limiting anytime during the active growing season (31).
Measured microsite field conditions are unknown.
Weather data compiled by Lipkin (23) for Adak (22 yr. record)
and Atka (1982-1983) show similar profiles for measured air
temperatures and precipitation; although York (35) noted Atka is
rainer than Adak. Summary data from Adak (recorded near the coast)
Habitat Associations - 1 can only be used to generally predict the climate of Mt. Reed where
the conditions are undoubtedly colder with much more snow, wind, and
fog (23).
Twenty year mean precipitation averages for Adak (02) amount to
168 cm/yr. distributed more or less evenly with slightly drier late
Spring and wetter later Autumn conditions. Additional, more specific
weather data for Adak is reported by Williams (34). Mean annual
temperature measured from 1950-1972 was 4.9 deg. C (40.9 deg. F); and
average monthly precipitation was 13.9 cm, the lowest in July and
highest in November. Winds of greater than 20 knots occur 295 days
per year, directed W-SW during 10 months and W during June and July
(34). Ground surface solar radiation measured for 41 days between
July 29 and Sept. 5, 1978 yielded data that for 19 inputs exceeded
0.5 cal./cm sq./min/ for greater than 4 hours with a maximum high of
1.21 cal./cm sq./min. on August 8, and a minimum low of 0.31
cal./cm sq./min. on Aug. 7 and 20 (34).

Habitat Associations - 2 (DRAFT) - Food Habits
Species FERN, SHIELD, ALEUTIAN
Species Id ESIS857001
Date 13 MAR 96

FOOD HABITS

TROPHIC LEVEL -
AUTOTROPH

Food Habits - 1 (DRAFT) - Environment Associations
Species FERN, SHIELD, ALEUTIAN
Species Id ESIS857001
Date 13 MAR 96

ENVIRONMENTAL ASSOCIATIONS

G = General A = Adult
LIM = Limiting RA = Resting Adult
J = Juvenile FA = Feeding Adult
RJ = Resting Juvenile BA = Breeding Adult
FJ = Feeding Juvenile P = Pupae
L = Larvae E = Egg
RL = Resting Larvae
FL = Feeding Larvae

LIFESTAGE ENVIRONMENTAL ASSOCIATIONS
G Terrestrial Features: Cliffs/ledges
G Terrestrial Features: Rock outcrops
G

Environment Associations - 1 (DRAFT) - Life History
Species FERN, SHIELD, ALEUTIAN
Species Id ESIS857001
Date 13 MAR 96

LIFE HISTORY

HABIT:
Herb (07,13,14,17,20,22,23,24,25,30,33).

LIFE CYCLE:
Perennial (07,13,14,17,20,22,23,24,25,30,33). The Aleutian
shield fern is a non-evergreen, herbaceous perennial as is typical
of many arctic-alpine species of ferns. Seasonally produced fronds
do not overwinter, being renewed each year from the perennating shoot
crown. Fronds of the next season's growth are initiated during the
Summer and Fall of the current growing season; but remain tightly
coiled and protected within the sheaflike cluster of persistent
stipe remnants until the following Spring (31).

TYPE OF REPRODUCTION:
Sexual (07,17,20,22,23,30,32,33). All stages of the Aleutian
shield fern's life cycle have not been observed. As is typcial of all
"true" ferns, one full generation consists of a dibiontic (2 living
phases) alternation between haploid (1N) and diploid (2N) phases.
Spores that may germinate will form a delicate, inconspicuous haploid
plant that bears male and/or female sex organs when mature.
Subsequent to fertilization, an embryo develops and grows into the
perennial diploid plant (that which has been collected to date).
Sexual reproductive success hinges on the ability of the species to
complete both haploid and diploid phases (31). This species regularly
produces spores (17,30,31) that show no evidence of abnormal
development.
Many ferns are known to reproduce asexually or "pseudosexually"
by replicating either/or both phases without union of sperm and egg.
Such diasporic or apogamous mechanisms do not appear operational in
this species. The apparent lack of specialized asexual mechanisms
is supported by the depauperate number of individuals and spotty

REPRODUCTIVE PHENOLOGY:
Germination dates are unknown (30,31). Leafing dates occur in
in Aleutian Spring - June(?) (30,31). Spore maturation and dispersal
dates are from July to September (30,31). This species appears only
to propagate (though infrequently) through spores. Although spores
are produced annually, successful sowing and germination are
infrequent. If spores germinate in the Fall after dispersal or in
the following Spring is unknown (31).
Annual production of leaves (is assumed to) occurs after the
habitat becomes snow-free during the Aleutian Spring. Eyerdam's 1932
Atka specimen collected on July 5 bears fully developed leaves and
mature spores. Adak specimens collected on Sept. 19, 1985, also
contained mature fronds and ripened spires; while plants observed on
on Aug. 17, 1987, only contained unripened, immature spores. Ripened
spores are readily released during the season of production (31).

SEX OR SPORE STATUS:
Homosporous (30,31). Most species of the genus Polystichum
produce a bisexual haploid phase, often with in-crossing barriers
Life History - 1 (DRAFT) - Life History
Species FERN, SHIELD, ALEUTIAN
Species Id ESIS857001
Date 13 MAR 96

that inhibit or precent self-fertilization (15). The low, highly
restricted gene pool of this species, coupled with an out-crossing
requirement, realistically may account for the low number of
populations and individuals (31).

POLLINATION, SPORE AND SEED DISSEMINATION:
Wind and/or seepage moisture are the spore disseminating agents
for this species (23,31). Spore dispersal affected by wind may
result in most spores being blown off the islands or, at least,
away from suitable habitat (23,31).

SEED BIOLOGY:
Virtually nothing is known about the spore biology of this
species. Spores are produced annually, in sporangia, clustered into
fertile patches (sori) on the undersurface of mature leaves. Six to
eight patches containing numerous sporangia (estimated >25) are
produced on most of the segments of each leaf. Sixty-four spores are
produced per sporangium measuring between 41 and 52 um in exospore
diameter (31).

POPULATION BIOLOGY:
The following discussion is purely conjectural except for data
relating to population density.
One population of unknown number of individuals is known to
(have) occur(ed) on Atka (17). Two populations are known from Adak,
one containing an estimated number of 12-15 individuals (partially
depleted by collecting) in 1975 (23,28), and another discovered in
1987 containing 7 individuals (5 sexually mature plants, 2 immature
plants) now reduced to 6 individuals because of substrate release of
one plant (29).
Undoubtedly population isolation, low gene pool, virtual lack
of interpopulational crossing, and specific requirements of habitat
are the species' principal limiting factors. Reproduction, survival,
and mortality rates are unknown. All populations may be very old,
possibly declining, as the natural course of mortality is not offset
by growth of new individuals (23).
Recovery potential through natural processes is doubtful. Some
enhancement might be possible through cultivation if a protocol
could be developed that would introduce biotypes from different
populations through crossing experiments. Such manipulations would
require destructive sampling of existing populations to obtain
spores. Until more source material is discovered, propagation is
not advisable, if not, impracticable (29,31).

ECOLOGICAL/EDAPHIC FACTORS:
Habitat characteristics of the 1987 Aleutian shield fern
population consist of exposed, weathered rock outcrops with rooting
substrate confined to fissures, crevices, and thinly mantled
horizontal ledges. The site is fully exposed to conditions of
climatic weathering. Dense fog blankets the habitat during the summer
months, except for brief periods when clear weather prevails. Hence,
during the growing season, incident solar radiation is intercepted
by fog that significantly lowers insolation values at the substrate
Life History - 2 (DRAFT) - Life History
Species FERN, SHIELD, ALEUTIAN
Species Id ESIS857001
Date 13 MAR 96

surface. Ground surface solar radiation values measured for 41 days
during the summer, 1978 on Adak are profiled by Williams (34).
Temperature and precipitation data (02,23,34) indicate mean annual
values of 4.9 deg. C and 13.9-16.8 cm/yr. These values may only
predict general climatic conditions on Mt. Reed where temperatures
are undoubtedly lower and much more snow, wind, and fog prevail (23).
Winds of greater than 20 knots occur 295 days per year (34). Winds
of greater force are experienced at the upper elevations on Mr.
Reed (31).
Fern habitat is situated between 1300 and 1600 feet elevation
on the east exposure of the north arm of Mt. Reed. It is located in
the South Adak region of folded, faulted and intensely altered
basaltic flows and pyroclastic rocks (Finger Bay Volcanics) (23,26).
The steep (50-75 deg.) upper talus/rubble slopes of Mt. Reed are
interrupted by near vertical, tilted rocky outcrops bearing crisp,
horizontal and vertical, fractures. Soils of such upland sites
consist of cryandepts and cryofolists and lithic cryofolists (23)
that are stabilized by low profile mixed Shrub-Forb-Herb vegetation.
Soil that accumulates to the surface of outcrop creases consists of
dark, extremely fine-grained particles. Texture and stickiness
indicate high (constant) moisture and mixed mineral/organic
composition (31).
Natural disturbance to the habitat results from wasting of the
outcrops. Superficial weather-abraiding effects may delay or
prematurely halt the annual growth cycle in years with abnormal
weather cycles. More severs impacts may result from freeze-thaw
cycles that loosen and pare away blocks of the outcrop. Downslope
creep of the vegetated talus slopes could contribute to
destabilization of upslope outcrops. Such threats may be magnified
by hiking or climbing near the site creating breaks in the vegetation
mat or dislodging rock (31).

TROPHIC STATUS:
Phototrophic (31).

CHARACTERISTIC DOMINANCE:
Component (29,31). The Aleutian shield fern is affiliated with
a loosely defined enclave of species without obvious characteristics
of dominance (29,31).

COMMUNITY ECOLOGY:
Species associated with the 1987 shield fern population are:
vascular plants; Cardamine bellidifolia, Carex spp., Cassiope
lycopodioides, Empetrum nigrum, Geum rossii, Lycopodium selago,
Oxyria digyna, Polygonum viviparum, Saxifraga punctata subsp.
insularis, and Saxifraga unalaschensis; bryophytes, Mnium magnifolium
and Rhytidiadelphus squarrosus (29).
It is unlikely that forces of competitive displacement,
positively or negatively, regulate population size or dynamics among
all species present in the habitat (29).

SPECIES INTERRELATIONSHIPS:
Not known; relationships remote or absent (31).
Life History - 3 (DRAFT) - Life History
Species FERN, SHIELD, ALEUTIAN
Species Id ESIS857001
Date 13 MAR 96

OTHER LIFE HISTORY DESCRIPTORS:
None.

Life History - 4 (DRAFT) - Management Practices
Species FERN, SHIELD, ALEUTIAN
Species Id ESIS857001
Date 13 MAR 96

MANAGEMENT PRACTICES

RESULT MANAGEMENT PRACTICE

Beneficial Stocking captive-reared wild-strain animals
Beneficial Maintaining undisturbed/undeveloped areas
Beneficial Transplanting wild animals
Beneficial Restricting/regulating human disturbance of populations
Beneficial Controlling/Removing Exotic Vertebrates
Adverse Collecting
Existing Collecting
Adverse Low Gene Pool
Existing Low Gene Pool

COMMENTS ON MANAGEMENT PRACTICES -
Past and Present Reasons for Status. The Aleutian shield fern is
is among the rarest vascular plants in North America with a total
known distribution restricted only to Atka and Adak Islands
(13,14,23,24,25,28,29).
Causes for such rarity are probably most profoundly historical
factors related to Pleistocene and Holocene paleoclimates (31). That
the Aleutian shield fern is derived from Asiatic ancestral stock is a
reasonable assumption, since it is most closely related to species
now found mainly in mountainous areas of the Sino-Himalayan region.
Plant colonization of the Aleutians undoubtedly resulted, in
part, from sources situated to the west (Kamchatka and Siberia).
Spores of ancestral stock most likely were conveyed from the west by
winds during the Late Tertiary (Pliocene) or more recently during the
Pleistocene or Holocene. Once founded on the Aleutians, this species
may have radiated along the island chain, but probably was never
plentiful. Episodic glaciation through the Pleistocene likely limited
and/or decimated populations to the extent that only biotypes remain
today (31).
The recent Holocene climate of the Aleutians is estimated at
10,000 yr. BP (01,05), following deglaciation of Wisconsin ice that
capped the mountainous island masses. The Holocene hypsithermal was
replaced by a climate of "...lower temperatures and greater
storminess..." (16) beginning about 3000 yr. BP. Post-hypsithermal
decay of the Aleutian climate may account for population decline and
isolation evidenced today by extreme distributional restriction.
It is conceivable also, that the Aleutian shield fern became founded
in the Aleutians as recently as the period of early Holocene climatic
amelioration; and that population decline and isolation has resulted
only in the past 3000 years (31).
Rarity of this species equates temporal factors of: source and
availability of founding propagules (presumably spores); time(s) of
arrival; success in establishment; repreoduction and radiation, or
lack thereof; and persistence in place (29). The current status of
this species would indicate that few and isolated populations
comprise a restricted gene pool with little or no inter- or
intra-populational gene flow. The potential for outcrossing between
populations is remote if at all, and intra-populational gene flow
Management Practices - 1 (DRAFT) - Management Practices
Species FERN, SHIELD, ALEUTIAN
Species Id ESIS857001
Date 13 MAR 96

appears equally unlikely given the low number of reproductively
mature individuals and the idiosyncracies of the fern sexual life
cycle (29,31).
The apparent inability of this species to
significantly/frequently reproduce is consistent with field
observations made from both populations occurring on Adak. Plants of
both populations lack any evidence of producing specialized asexual
diasporic structures or haploid alternate phase plantlets (31).
Two juvenile plants (sexually immature) were discovered in the
1987 Adak population suggest that some reproduction still does occur.
However, the origin and age of these individuals can be presumed only
as recent and derived from within the population. The expectation
that they will develop to sexual maturity is uncertain (31).
Reproductive rate and frequency may be so low that premature failure
or insufficient population replenishment may not offset later
mortality (23).
Future Perceived Threats. Population decline due to natural
consequences of habitat alteration, scarcity, low gene pool, and
biological fitness of the species has been compounded by unintended
anthropogenic insults on both Atka and Adak Islands. Collecting for
scientific purposes is a known cause for loss of individuals from all
known populations. There is now an adequate specimen record for
this rare species, and, until additional populations are discovered,
future collecting should be strictly prohibited (29).
Unknown negative impacts may have resulted from introduced
ungulates on both islands. European reindeer were introduced onto
Atka in 1914 and have severely overgrazed the west end of the island
(13,14,23). Caribou, introduced onto Adak in 1958 (13), have not
yet shown the same degree of impact. At least for the Adak
populations, they are situated on steep rocky outcrops where caribou
foraging would be improbably (29).
The most predictable future threats are mediated by human
activity. Site visitation to known populations or surface-resource
land development will gradually alter or certainly destroy suitable
habitat. Such threats can easily minimized or eliminated by careful
management. Areas where the fern is known to occur should be declared
critical habitat, but markers or exclosures should be avoided so as
not to draw attention to or destabilize these areas (29).

UNAPPROVED PLAN:
Currently, no recovery plan. Development of a recovery plan - if
determined to be beneficial to the species - will be initiated in
1989.

No approved recovery plan due to the recent date of listing and
current lack of information on reproductive ecology and limiting
factors.
Current and planned activities to benefit the species include
education and field surveys to locate additional
specimens/populations. The Service is also coordinating with the U.S.
Navy to restrict human access to the Adak Island population site.
Recovery activities in the future may include controlling exotic
Management Practices - 2 (DRAFT) - Management Practices
Species FERN, SHIELD, ALEUTIAN
Species Id ESIS857001
Date 13 MAR 96

vertebrates with fencing, transplanting and/or cultivating
individuals for reintroduction and restricting access and
development.

Management Practices - 3 (DRAFT) - References
Species FERN, SHIELD, ALEUTIAN
Species Id ESIS857001
Date 13 MAR 96

References

***** REFERENCES FOR ALL NARRATIVES EXCEPT N-OCCURRENCE *****

01 Ager, T.A. 1982. Vegetational History of Western Alaska During the
Wisconsin Glacial Interval and Holocene. pp. 75-92. In D.M.
Hopkins et al. Paleoecology of Beringia. Academic Press, New York.
02 Amundsen, C.C. 1985. Central Aleutian Tundra: Ecological
Manifestations of Maritime Tundra Landscapes in the Central
Aleutian Islands (Amchitka, Adak) Alaska. Final Report prepared
for Department of Energy, ORO-4180-10. 77 pp. + appendices
I,II,III.
03 Anderson, J.R., E.E. Hardy, J.T. Roach, and R.E. Witmer. 1976.
A Land Use and Land Cover Classification System for Use with
Remote Sensor Data. Geol. Sur. Prof. Paper 964. 28 pp.
04 Ayensu, E.S., and R.A. DeFilipps. 1978. Endangered and Threatened
Plants of the United States. Smithsonian Institution and World
Wildlife Fund. Washington, D.C. 403 pp.
05 Black, R.F. 1976. Influence of holocene climatic changes on Aleut
expansion into the Aleutian Islands, Alaska. Anthropological
Papers, Univ. Alaska. 18: 31-42.
06 Bold, H.C., C.J. Alexopoulos, and T. Delevoryas. 1987. Morphology
of Plants and Fungi. 5th Ed. Harper and Row, New York. 912 pp.
07 Christensen, C. 1938. On Polystichum aleuticum C. Chr., a new
North American species. Amer. Fern J. 28: 111-112.
08 Department of Interior. Fish and Wildlife Service. 1975.
Threatened or Endangered Fauna or Flora: Review of Status of
Vascular Plants and Determination of "Critical Habitat." Federal
Register 41: 27826.
09 Department of Interior. Fish and Wildlife Service. 1976.
Endangered and Threatened Species: Plants. Federal Register 41:
24560.
10 Department of Interior. United States Fish & Wildlife Service.
1980. Endangered and Threatened Wildlife and Plants: Review of
Plant Taxa for Listing as Endangered or Threatened Species.
Federal Register 45: 82532.
11 Department of Interior. Fish and Wildlife Service. 1983.
Endangered and Threatened Wildlife and Plants: Supplement to
Review of Plant Taxa for Listing: Proposed Rule. Federal Register
43: 53657.
12 Department of Interior. Fish and Wildlife Service. 1985.
Endangered and Threatened Wildlife and Plants; Review of Plant
Taxa for Listing as Endangered or Threatened Species; Notice of
Review. Federal Register 50: 39573.
13 Department of Interior. Fish and Wildlife Service. 1987.
Endangered and Threatened Wildlife and Plants; Proposed Endangered
Status for Polystichum aleuticum. Federal Register 52:
13729-13732.
14 Department of Interior. Fish and Wildlife Service. 1988.
Endangered and Threatened Wildlife and Plants; Determination of
Endangered Status for Polystichum aleuticum. Federal Register 53:
4626-4630.
15 Evans, A.M. 1988. Personal communication. Department of Botany,
References - 1 (DRAFT) - References
Species FERN, SHIELD, ALEUTIAN
Species Id ESIS857001
Date 13 MAR 96

University of Tennessee, Knoxville, Tennessee.
16 Heusser, C.J. 1978. Postglacial vegetation on Adak Island,
Aleutian Islands, Alaska. Bull. Torrey Bot. Club 105: 18-23.
17 Hulten, E. 1936. New or notable species from Alaska. Contributions
to the flora of Alaska I. Svensk Bot. Tidskr. 30: 515-528.
18 Hulten, E. 1941. Flora of Alaska and Yukon, 1-10. Part 1, pp. 30.
Lunds. Universitets Arsskrift N.F., Avd. 2, 37: 1-46:1
(1941-1950).
19 Hulten, E. 1960. Flora of the Aleutian Islands. 2nd Ed. J.
Cramer, Weinheim/Bergstr. 376 pp. + 533 maps + 33 figs.
20 Hulten, E. 1968. Flora of Alaska and Neighboring Territories.
Stanford University Press, Stanford. 1008 pp.
21 Kartesz, J.T. and Rosemarie Kartesz. 1980. A Synonymized Checklist
of the Vascular Flora of the United States, Canada, and Greenland.
The University of North Carolina Press, Chapel Hill. 500 pp.
22 Lellinger, D.B. 1985. A Field Manual of the Ferns & Fern-Allies of
the United States and Canada. Smithsonian Institution Press,
Washington, D.C. 389 pp.
23 Lipkin, R. 1985. Status Report of Polystichum aleuticum C. Chr.
U.S. Fish and Wildlife Service, Office of Endangered Species,
Anchorage. 21 pp. + appendix A (4 figs.), appendix B (9 figs.),
appendix C (5 figs.), appendix D (3 figs.).
24 Murray, D.F. 1980. Threatened and Endangered Plants of Alaska.
U.S. Department of Agriculture, Forest Service, and the U.S.
Department of the Interior, Bureau of Land Management. (pp. 12-13)
59 pp.
25 Murray, D.F. and R. Lipkin. 1987. Candidate Threatened and
Endangered Plants of Alaska, with Comments on other Rare Plants.
University of Alaska Museum, Fairbanks, Alaska. (pp. 14-15) 76 pp.
26 Scholl, D.W., H.G. Greene, and M.S. Marlow. 1970. Eocene age of
the Adak 'Paleozoic(?)' rocks, Aleutian Islands, Alaska. Geol.
Soc. Amer. Bull. 81: 3583-3592.
27 Shacklette, H.T., et al. 1969. Vegetation of Amchitka Island,
Aleutian Islands, Alaska. U.S. Geol. Surv. Prof. Paper 648. 66 pp.
28 Smith, D.K. 1985. Polystichum aleuticum from Adak Island, Alaska,
a second locality for the species. Amer. Fern J. 75: 72.
29 Smith, D.K. 1987. Polystichum aleuticum Chr. on Adak Island,
Alaska: Status Report for 1987. U.S. Fish and Wildlife Service,
Office of Endangered Species, Anchorage, Alaska. 15 pp. + appendix
(7 figs.).
30 Smith, D.K. 1988a. The status of Polystichum aleuticum Chr. in
Hulten. in litt.
31 Smith, D.K. 1988b. Personal information and communication. Dept.
of Botany, University of Tennessee, Knoxville, Tennessee.
32 Wagner, D. 1979. Systematics of Polystichum in western North
America north of Mexico. Pteridologia 1: 1-64.
33 Welsh, S.L. 1974. Anderson's Flora of Alaska and adjacent parts of
Canada. Brigham Young University Press, Provo, Utah. 724 pp.
34 Williams, M.P. 1980. Studies of Elymus mollis directed towards its
use in Revegetation of Maritime Tundra. M.S. Thesis. University
of Tennessee, Knoxville. 123 pp.
35 York, C.L. 1950. A Contribution to the Ecology of the Plants of
Atka Island, with Notes on the Flora of Adak Island, Alaska.
References - 2 (DRAFT) - References
Species FERN, SHIELD, ALEUTIAN
Species Id ESIS857001
Date 13 MAR 96

Ph.D. Dissertation, University of Texas, Austin. 165 pp.

***** REFERENCES FOR N-OCCURRENCE NARRATIVE ONLY *****

01 Amundsen, C.C. 1985. Central Aleutian Tundra: Ecological
Manifestations of Maritime Tundra Landscapes in the Central
Aleutian Islands (Amchitka, Adak) Alaska. Final Report prepared
for Department of Energy, ORO-4180-10. 77 pp. + appendices
I,II,III.
02 Black, R.F. 1976. Influence of holocene climatic changes on Aleut
expansion into the Aleutian Islands, Alaska. Anthropological
Papers, Univ. Alaska 18:31-42.
03 Christensen, C. 1938. On Polystichum aleutium C. Chr., a new North
American species. Amer. Fern J. 28:111-112.
04 Friedman, B.F. 1984. (pp. 3-4 - 3-28) in Feasibility Study Data
Collection Program for the Proposed Hydroelectric Project at Atka,
Alaska. Northern Technical Services, Inc. and Van Gulik and
Associates, Inc. Final Report prepared for Alaska Power Authority.
05 Fries. 1984. in litt., fide Lipkin 1985.
06 Hulten, E. 1936. New or notable species from Alaska. Contributions
to the flora of Alaska I. Svensk Bot. Tidskr. 30: 515-528.
07 Hulten, E. 1940. History of botanical exploration in Alaska and
Yukon territories from the time of discovery to 1940. Bot. Not.
289-346.
08 Hulten, E. 1941. Flora of Alaska and Yukon, 1-10. Part 1, pp. 30.
Lunds. Universitets Arsskrift N.F., Avd. 2, 37L 1-46:1
(1941-1950).
09 Hulten, E. 1960. Flora of the Aleutian Islands. 2nd Ed. J. Cramer,
Weinheim/Bergstr. 376 pp. + 533 maps + 33 figs.
10 Hulten, E. 1968. Flora of Alaska and Neighboring Territories.
Stanford University Press, Stanford. 1008 pp.
11 Lipkin, R. 1985. Status Report of Polystichum aleuticum C. Chr.
U.S. Fish and Wildlife Service, Office of Endangered Species,
Anchorage. 21 pp. + appendix A (4 figs.), appendix B (9 figs.),
appendix C (5 figs.), appendix D (3 figs.).
12 Murray, D.F. 1980. Threatened and Endangered Plants of Alaska.
U.S. Department of Agriculture, Forest Service, and the U.S.
Department of the Interior, Bureau of Land Management. (pp. 12-13)
59 pp.
13 Murray, D.F., and R. Lipkin. 1987. Candidate Threatened and
Endangered Plants of Alaska, with Comments on other Rare Plants.
University of Alaska Museum, Fairbanks, Alaska. (pp. 14-15) 76 pp.
14 Smith, D.K. 1985. Polystichum aleuticum from Adak Island, Alaska,
a second locality for the species. Amer. Fern J. 75: 72.
15 Smith, D.K. Personal information and communication. Department of
Botany, University of Tennessee, Knoxville, TN. (1987).
16 Smith, D.K. 1987. Polystichum aleuticum Chr. on Adak Island,
Alaska: Status Report for 1987. U.S. Fish and Wildlife Service,
Office of Endangered Species, Anchorage, Alaska. 15 pp. +
appendices (7 figs.).
17 Talbot, S.S. 1986. A Search for Polystichum aleuticum
(POLYPODIACEAE) on Adak Island, Alaska: Status Report Supplement.
References - 3 (DRAFT) - References
Species FERN, SHIELD, ALEUTIAN
Species Id ESIS857001
Date 13 MAR 96

U.S. Fish and Wildlife Service, Office of Endangered Species,
Anchorage, Alaska. 1-21 pp.
18 United States Geological Survey, National Mapping Division. 1982.
Ecoregions and Land-Surface Forms of Alaska and Hawaii. in
Ecoregion, Land-Surface Form and Hydrologic Unit Maps of the
United States. Biological Services Program. Fish and Wildlife
Service/OBS-82/09 (1982).
19 United States Geological Survey. 1980. 'adapted' Hydrologic
Unit Map of Alaska and Hawaii. in Ecoregions, Land-Surface Form
and Hydrologic Unit Maps of the United States. Biological Services
Program. Fish and Wildlife Service/OBS-82/09 (1982).
20 Wagner, D. 1979. Systematics of Polystichum in western North
America north of Mexico. Pteridologia 1: 1-64.
21 Welsh, S.L. 1974. Anderson's Flora of Alaska and adjacent parts
of Canada. Brigham Young University Press, Provo, Utah. 724 pp.
22 Williams, M.P. 1978. in litt. U.S. Fish and Wildlife Service
Files, Anchorage, Alaska.

References - 4