[Federal Register: June 1, 2010 (Volume 75, Number 104)]
[Proposed Rules]
[Page 30313-30318]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr01jn10-27]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R4-ES-2009-0020]
[MO 92210-0-0008-B2]
Endangered and Threatened Wildlife and Plants; 90-Day Finding on
a Petition To List Castanea pumila var. ozarkensis
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Notice of petition finding and initiation of status review.
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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a
90-day finding on a petition to list Castanea pumila var. ozarkensis
(Ozark chinquapin), a tree, as endangered or threatened under the
Endangered Species Act of 1973, as amended (Act). Based on our review,
we find that the petition presents substantial scientific or commercial
information indicating that listing this species may be warranted.
Therefore, with the publication of this notice, we are initiating a
status review of the species to determine if listing Castanea pumila
var. ozarkensis is warranted. To ensure that the review is
comprehensive, we are requesting scientific and commercial data and
other information regarding this species. Based on the status review,
we will issue a 12 month finding on the petition, which will address
whether the petitioned action is warranted, as provided in section
4(b)(3)(B) of the Act.
DATES: To allow us adequate time to conduct this review, we request
that we receive information on or before August 2, 2010. Please note
that if you are using the Federal eRulemaking Portal (see ``ADDRESSES''
section, below), the deadline for submitting an electronic comment is
11:59 p.m. Eastern Daylight Savings Time on this date.
After August 2, 2010, you must submit information directly to the
Field Office (see FOR FURTHER INFORMATION CONTACT section below).
Please note that we might not be able to address or incorporate
information that we receive after the above requested date.
ADDRESSES: You may submit information by one of the following methods:
Federal eRulemaking Portal: http://www.regulations.gov. In
the box that reads ``Enter Keyword or ID,'' enter the Docket number for
this finding, which is FWS-R4-ES-2009-0020. Check the box that reads
``Open for Comment/Submission,'' and click the Search button. You
should then see an icon that reads ``Submit a Comment.'' Please ensure
that you have found the correct rulemaking before submitting your
comment.
U.S. mail or hand-delivery: Public Comments Processing,
Attn: FWS-R4-ES-2009-0020; Division of Policy and Directives
Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive,
Suite 222; Arlington, VA 22203.
We will post all information we receive on http://
www.regulations.gov. This generally means that we will post any
personal information you provide us (see the Request for Information
section below for more details).
FOR FURTHER INFORMATION CONTACT: Mark Sattelberg, Field Supervisor,
Arkansas Ecological Services Field Office, 110 South Amity Road, Suite
300, Conway, AR 72032; by telephone (501-513-4470); or by facsimile
(501-513-4480). If you use a telecommunications device for the deaf
(TDD), please call the Federal Information Relay Service (FIRS) at 800-
877-8339.
SUPPLEMENTARY INFORMATION:
Request for Information
When we make a finding that a petition presents substantial
information indicating that listing a species may be warranted, we are
required to promptly review the status of the species (status review).
For the status review to be complete and based on the best available
scientific and commercial information, we request information on
Castanea pumila var. ozarkensis from governmental agencies, Native
American Tribes, the scientific community, industry, and any other
interested parties. We seek information on:
(1) The species' biology, range, and population trends, including:
(a) Habitat requirements for feeding, breeding, and sheltering;
(b) Genetics and taxonomy;
(c) Historical and current range, including distribution patterns;
(d) Historical and current population levels, and current and
projected trends; and
(e) Past and ongoing conservation measures for the species, its
habitat, or both.
(2) The factors that are the basis for making a listing
determination for a species under section 4(a) of the Endangered
Species Act of 1973, as amended (Act) (16 U.S.C. 1531 et seq.), which
are:
(a) The present or threatened destruction, modification, or
curtailment of its habitat or range;
(b) Overutilization for commercial, recreational, scientific, or
educational purposes;
(c) Disease or predation;
(d) The inadequacy of existing regulatory mechanisms; or
(e) Other natural or manmade factors affecting its continued
existence.
(3) The potential effects of climate change on this species and its
habitat.
If, after the status review, we determine that listing Castanea
pumila var. ozarkensis is warranted, we will propose critical habitat
(see definition in section 3(5)(A) of the Act), in accordance with
section 4 of the Act, to the maximum extent prudent and determinable at
the time we propose to list the species. Therefore, within the
geographical range currently occupied by Castanea pumila var.
ozarkensis, we request data and information on:
(1) What may constitute ``physical or biological features essential
to the conservation of the species,''
(2) Where these features are currently found, and
(3) Whether any of these features may require special management
considerations or protection.
In addition, we request data and information on ``specific areas
outside the geographical area occupied by the species'' that are
``essential to the conservation of the species.'' Please provide
specific comments and information as to what, if any, critical habitat
you think we should propose for designation if the species is proposed
for listing, and why such habitat meets the requirements of section 4
of the Act.
Please include sufficient information with your submission (such as
scientific journal articles or other publications) to allow us to
verify any scientific or commercial information you include.
Submissions merely stating support for or opposition to the action
under consideration without providing supporting information, although
noted, will not be considered in making a determination. Section
4(b)(1)(A) of the
[[Page 30314]]
Act directs that determinations as to whether any species is an
endangered or threatened species must be made ``solely on the basis of
the best scientific and commercial data available.''
You may submit your information concerning this status review by
one of the methods listed in the ADDRESSES section. If you submit
information via http://www.regulations.gov, your entire submission--
including any personal identifying information--will be posted on the
website. If you submit a hardcopy that includes personal identifying
information, you may request at the top of your document that we
withhold this personal identifying information from public review.
However, we cannot guarantee that we will be able to do so. We will
post all hardcopy submissions on http://www.regulations.gov.
Information and supporting documentation that we received and used
in preparing this finding, will be available for you to review at
http://www.regulations.gov, or you may make an appointment during
normal business hours at the U.S. Fish and Wildlife Service, Arkansas
Ecological Services Field Office (see FOR FURTHER INFORMATION CONTACT).
Background
Section 4(b)(3)(A) of the Act (16 U.S.C. 1533(b)(3)(A)) requires
that we make a finding on whether a petition to list, delist, or
reclassify a species presents substantial scientific or commercial
information indicating that the petitioned action may be warranted. We
are to base this finding on information provided in the petition,
supporting information submitted with the petition, and information
otherwise available in our files. To the maximum extent practicable, we
are to make this finding within 90 days of our receipt of the petition
and publish our notice of the finding promptly in the Federal Register.
Our standard for substantial scientific or commercial information
within the Code of Federal Regulations (CFR) with regard to a 90-day
petition finding is ``that amount of information that would lead a
reasonable person to believe that the measure proposed in the petition
may be warranted'' (50 CFR 424.14(b)). If we find that substantial
scientific or commercial information was presented, we are required to
promptly review the status of the species, which is subsequently
summarized in our 12-month finding.
Petition History
On January 6, 2004, we received a petition, dated December 28,
2003, from Mr. Joe Glenn of Hodgen, Oklahoma, requesting that the
Castanea pumila var. ozarkensis (Ozark chinquapin) be listed under the
Act as a candidate species. The petition clearly identified itself as
such and included the requisite identification information for the
petitioner(s), as required by 50 CFR 424.14(a). The petition contained
supporting information regarding the species' ecology, threats to the
species, and survey and occurrence data for a portion of the Ouachita
Highlands in southeastern Oklahoma. We acknowledged receipt of the
petition in a February 2, 2004, letter to Mr. Glenn. In that letter, we
advised the petitioner that, due to a significant number of court
orders and settlement agreements in Fiscal Year 2004, we would not be
able to address the petitioned request at that time.
Previous Federal Action
On July 1, 1975 (40 FR 27924), Castanea pumila var. ozarkensis was
included as one of the 3000 plant species under status review. It was
proposed or reviewed by the Service for federal listing as an
endangered species under the Act in 1976 (41 FR 17 24524). We, however,
did not finalize that proposed rule (U.S. Fish and Wildlife Service
1988). Castanea pumila var. ozarkensis became a category 2 candidate on
December 15, 1980 (45 FR 82480 82569). It was again advertised as a
category 2 candidate on September 27, 1985 (50 FR 53640 53670). The
status changed on February 21, 1990 (55 FR 6184 6229) to a category 1
candidate species . On September 30, 1993 (58 FR 51144 51190) the
status changed back to a category 2 candidate species for listing.
Species Information
Castanea pumila var. ozarkensis was first identified as a separate
species (Castanea ozarkensis) by Ashe (1923, p. 60). Ashe described the
range of the species as ``common north of the Arkansas River and
westward from Center Ridge, Arkansas, northward to southwestern
Missouri and westward to the Valley of the White River'' (Tucker 1983,
p. 2). Ashe (1923, p. 361) also described a second species, Castanea
arkansana, in Arkansas. Ashe (1924, p. 45) reduced Castanea arkansana
to varietal status as Castanea ozarkensis var. arkansana. Little (1953,
p. 2, in Tucker 1983) reduced Castanea arkansana to synonymy with
Castanea ozarkensis. Tucker (1975, p. 2, in Tucker 1983) reduced
Castanea ozarkensis to a variety of the more common Castanea pumila
(Castanea pumila var. ozarkensis (Ashe) Tucker) and concurred with
Little's (1953) treatment of Castanea arkansana. Johnson (1988, p. 43)
published a revision of Castanea sect. Balanocastanion concurring with
Tucker's reduction of Castanea ozarkensis to a variety of Castanea
pumila. Tucker's reduction is further supported in Smith's (1994, p.
54) Keys to the Flora of Arkansas.
Castanea pumila var. ozarkensis is a tree in the beech family
(Fagaceae). Castanea pumila var. ozarkensis has leaves 10 to 25
centimeters (4 to 10 inches (in)) long, broadly lanceolate to
elliptical, with coarse teeth that are 2.5 to 9 millimeters (mm) (0.1
to 0.35 in) long with whitish or yellowish-cream stellate (star-shaped)
hairs on the lower surfaces. The bark is light brown to reddish brown
or grayish, with broad flat ridges that break into loose plate-like
scales. The fruits are subglobose to ovoid nuts up to approximately 20
mm (0.8 in) long enclosed in a spiny burr with burrs being solitary or
in groups of two or three. The subspecies is distinguished from
Castanea pumila var. pumila (Allegheny chinquapin) by the larger leaf
size, larger teeth, and larger fruit, which also have hairs (Steyermark
1963, p. 531; Smith 1994, p. 54).
Castanea pumila var. ozarkensis was historically a medium-sized
tree species that once grew to 20 meters (m) (65 feet (ft)), although
usually much shorter, but now rarely reaches heights of more than 9 m
(30 ft). Trunks develop from stump sprouts as well as from seeds, but
in recent years, new growth is generally from sprouts. Trees reaching
the age to produce fruit (4 to 5 years; Paillet 1993, p. 262) are
increasingly rare due to the fungus parasite (Cryphonectria parasitica)
that is responsible for the chestnut blight disease, which has
adversely affected many Castanea spp. populations in the United States
(Tucker 1983, pp. 8-9; Steyermark 1963, p. 531). Paillet (1991, p. 10;
1993, pp. 261-262) noted an area on the Ozark National Forest that was
cut 4-5 years previously that was full of broad chinquapin crowns and
the ground littered with burs from the summer's nut crop. Based on
Paillet's observation nearly 20 years ago, it is plausible to assume
that Castanea pumila var. ozarkensis may produce fruit prior to
succumbing to the blight at some localities. However, Paillet (1993, p.
262) reported that these sites were increasingly rare in the early
1990's.
Castanea pumila var. ozarkensis has been described as historically
common in thin woods, edges of woods, and mid-successional woods
(Tucker 1983, pp. 8-9). This tree historically occupied
[[Page 30315]]
canopy and subcanopy positions on a variety of habitats, including dry
upland deciduous or mixed hardwood-pine communities on acid soils of
ridge-tops, upper slopes adjacent to ravines and gorges, and the tops
of sandstone bluffs (C. McDonald 1987, personal communication (pers.
comm.)). Associated trees in these habitats include Quercus alba (white
oak), Quercus stellata (post oak), Quercus rubra (northern red oak),
Nyssa sylvatica (black gum), Pinus echinata (short-leaf pine), Morus
rubra (mulberry), Carya spp. (hickories), Ulmus americana (American
elm), and Ostrya virginiana (ironwood) (Steyermark 1963, p. 531; G.
Tucker 1976, pers. comm.). Soil conditions typically are acid and
sandstone-derived, and moisture conditions vary from mesic to dry;
shade is variable (G. Tucker 1976, pers. comm.; C. McDonald 1987, pers.
comm.).
Castanea pumila var. ozarkensis is generally fire tolerant, but
sprouts may be damaged by fire (Kral 1983, p. 287). Due to blight, dead
sprouts and dead stump wood may act as a fuel for fire and affect the
remaining live sprouts.
Distribution and Status
Castanea pumila var. ozarkensis is located throughout the Interior
Highlands in Arkansas (34 counties), Missouri (9 counties), and
Oklahoma (8 counties)(Kratesz 1994). Castanea pumila var. ozarkensis
currently remains widespread within the Interior Highlands of Arkansas
and is less common and widespread within the uplands of southwestern
Missouri and eastern Oklahoma. Localities with seed- producing trees
are greatly diminished from pre-blight era. However, asexually
reproducing populations still occur throughout the tree's historic
distribution. Herbarium specimens are all that remains to support the
existence of Castanea pumila var. ozarkensis in Alabama (four
localities in the Appalachian Mountains). Data to support the abundance
and distribution of Castanea pumila var. ozarkensis in the Appalachian
Mountains is lacking, and researchers have been unable to find extant
populations in this region. The Interior Highlands contain the only
known extant populations of Castanea pumila var. ozarkensis at this
time (Johnson 1988, pp. 43-45).
At present, there are greater than 300 element occurrences in the
Interior Highlands. Individual site records commonly report multiple
Castanea pumila var. ozarkensis sprout clumps. These vary from tens to
hundreds of individual sprout clumps at an element occurrence record
site (Kratesz 1994). At present, Castanea pumila var. ozarkensis
occurrence and status is tracked by all of the State heritage programs
and the U.S. Department Agriculture's Forest Service within the tree's
range.
Evaluation of Information for this Finding
Section 4 of the Act (16 U.S.C. 1533) and its implementing
regulations at 50 CFR 424 set forth the procedures for adding a species
to, or removing a species from, the Federal Lists of Endangered and
Threatened Wildlife and Plants. A species may be determined to be an
endangered or threatened species due to one or more of the five factors
described in section 4(a)(1) of the Act:
(A) The present or threatened destruction, modification, or
curtailment of its habitat or range;
(B) Overutilization for commercial, recreational, scientific, or
educational purposes;
(C) Disease or predation;
(D) The inadequacy of existing regulatory mechanisms; or
(E) Other natural or manmade factors affecting its continued
existence.
In making this 90-day finding, we evaluated whether information
regarding threats to the Castanea pumila var. ozarkensis, as presented
in the petition and other information available in our files, is
substantial, thereby indicating that the petitioned action may be
warranted. Our evaluation of this information is presented below.
A. The Present or Threatened Destruction, Modification, or Curtailment
of Habitat or Range
Information Provided in the Petition
The petition cites several factors regarding the destruction and
modification of Castanea pumila var. ozarkensis habitat, including:
(1) The range of Castanea pumila var. ozarkensis has been reduced
over past times (geologic time scale) because it once could have
occupied the entire Lower Mississippi Valley. Based on the petitioner's
personal observations, several million acres of suitable habitat in the
Interior Highlands on both public (particularly on national forest
lands in the region) and private lands have been lost since the 1960s,
mostly due to anthropogenic (human) disturbance.
(2) Late successional habitats have been reduced through ``pine
plantation style'' forest management, which has reduced habitat quality
through prescribed burning (including the fact that vigorous Castanea
pumila var. ozarkensis growth did not occur at prescribed burn sites
studied by the petitioner in Oklahoma).
(3) Castanea pumila var. ozarkensis is a late successional obligate
as it relates to seedling establishment.
Evaluation of Information Provided in the Petition and Available in
Service Files
With regard to the amount of habitat modification and alteration
that has occurred within the range of Castanea pumila var. ozarkensis,
we generally find that the information presented by the petition is
speculative and not substantial. Further, no supporting information was
presented to verify the petition's claim that Castanea pumila var.
ozarkensis could have once occupied the entire Lower Mississippi
Valley. Information provided in the petition and available in our files
includes references to records from Louisiana, Mississippi, and
Alabama. Johnson (1988, pp. 41-45) recognized Castanea pumila var.
ozarkensis records from the Interior Highlands and Appalachian
Mountains. While there is support for an Appalachian-Ozarkian floristic
relationship, floristic relationships to the lower Mississippi Valley
and Gulf Coastal Plain can only be considered speculative at this time
(Johnson 1988, p. 47).
The habitat loss claims in the petition are not supported in
available, peer- reviewed literature and are contrary to other existing
information in our files. The Ozark-Ouachita Highlands Assessment
(OOHA) 1999 Terrestrial Vegetation and Wildlife Report, prepared by a
collaborative team of natural resource specialists and research
scientists, examined historic and existing forest conditions throughout
the Interior Highlands of Arkansas, Missouri, and Oklahoma (U.S. Forest
Service 1999, section 5). The area of analysis overlaps much of the
range of Castanea pumila var. ozarkensis. OOHA descriptions of
vegetation cover or silvicultural practices do not indicate significant
reductions in suitable habitat for Castanea pumila var. ozarkensis.
Oak-hickory and oak-pine forest types continue to be common forest
types in the Interior Highlands. The upland oak-hickory forest type
provided the dominant cover within the region at the time of the OOHA.
It covered 15 million acres (6.1 million hectares) or about 36 percent
of the area. The oak-pine forest type provided the second most
extensive cover. It covered 4.4 million acres (1.8 million hectares) or
11 percent of the area.
Ashe (1923) described the range of the species as ``common north of
the Arkansas River and westward from
[[Page 30316]]
Center Ridge, Arkansas, northward to southwestern Missouri and westward
to the Valley of the White River.'' Steyermark (1963, p. 531) states
that Louisiana and Mississippi are sometimes included as part of the
Castanea pumila var. ozarkensis range, but specimens examined from
those States have been proven not to be Castanea pumila var.
ozarkensis. This is contrary to the statements made by the petitioner
which states that the species occurs in Louisiana and Mississippi.
With regard to the reduction of late successional habitats, the
OOHA recognized Castanea pumila var. ozarkensis as a species of
viability concern, the habitat description being ``woodland, fire
maintained'' (U.S. Forest Service 1999, p. 137). Loss of natural fire
regimes is recognized as a threat to the health and sustainability of
oak-hickory and oak-pine ecosystems in which Castanea pumila var.
ozarkensis occurs (Spetich 2004, pp. 49-50 and 65-66). However, given
the understanding of fire as it relates to ecosystem health and
sustainability within most of the habitats where Castanea pumila var.
ozarkensis is known to occur, we cannot conclude that prescribed
burning is negatively influencing the species, even with the knowledge
that individual sprout clumps may be top-killed during prescribed
burns. Prescribed fire reduces fuel availability in the forest, which
reduces the threat of catastrophic wildfires that are likely a greater
threat to Castanea pumila var. ozarkensis than prescribed fire.
The petition claims, based on the petitioner's personal
observations, that the species is dependent on mesic conditions for
seedling establishment and growth. The petition also states that
Castanea pumila var. ozarkensis occurs in areas with abrupt changes in
topography, including talus flow margins, drainage margins, steep upper
slopes, rocky outcrops, and ridge tops; he also quoted a historical
reference (Palmer 1923) that stated a similar array of habitat types.
These descriptions tend to be more indicative of drier type areas and
not of mesic, closed canopy forest. While the species is known to occur
on mesic sites, mesic site obligation is not in alignment with widely
accepted ecological descriptions and dynamics known to sustain most of
the forested ecosystems where this species is currently found. Castanea
pumila var. ozarkensis is common in dry deciduous or mixed hardwood-
pine communities. Turner (1937) said of Castanea pumila var.
ozarkensis, ``Although it grows better in soils fairly well supplied
with moisture, it also grows on rocky, rather dry slopes and
hilltops.'' It is most common on upland slopes and ridges, cliff
margins, and talus slopes, where it is found on soils derived from
sandstone, limestone, or on chert-rich, clayey soils.
The petition also states that Castanea pumila var. ozarkensis is a
late seral obligate and that excessive shading contributes to branch
mortality and crown retardation. These characteristics would not be
expected in a species that needs late successional forest conditions
for optimal growth. Tucker (1983, p. 15) stated that Castanea pumila
var. ozarkensis formerly was a member of the climax community, but
presently is one of the first species to regenerate following a
disturbance (e.g., clear-cut, prescribed fire). Paillet (1991, p. 10;
1993, pp. 261-262) noted an area on the Ozark National Forest that was
cut 4 to- 5 years previously that was full of broad chinquapin crowns
and the ground littered with burs from the summer's nut crop. The
species requires sunlight to establish seedlings, which, again, is not
characteristic of late successional forest conditions that were fire-
maintained. Information in our files does not support the petitioner's
claim that this species is a late seral obligate. The species is found
on a variety of aspects and forest community types on the Ouachita and
Ozark National Forests. Information in our files indicates that
Castanea pumila var. ozarkensis prefers forests at an early seral
stage.
Summary of Factor A
The information in our files does not support the petition's claim
that Castanea pumila var. ozarkensis has suffered a significant range
reduction. While there is support for an Appalachian-Ozarkian floristic
relationship, floristic relationships to the lower Mississippi Valley
and Gulf Coastal Plain can only be considered speculative at this time
(Johnson 1988, p. 47). Castanea pumila var. ozarkensis is still
widespread and abundant throughout the majority of its extant range in
the Interior Highlands, particularly on public lands.
The information in our files also does not support the petition's
claim that Castanea pumila var. ozarkensis habitat has been reduced due
to prescribed burning. The habitat description for Castanea pumila var.
ozarkensis is described as ``woodland, fire maintained'' (U.S. Forest
Service 1999, p. 137). Loss of natural fire regimes is recognized as a
threat to the health and sustainability of oak-hickory and oak-pine
ecosystems in which Castanea pumila var. ozarkensis occurs (Spetich
2004, pp. 49-50 and 65-66).
In addition, information in our files does not support the
petition's claim that Castanea pumila var. ozarkensis habitat and
seedling establishment have been reduced due to a reduction in late
successional and mesic habitat. Tucker (1983, p. 15) stated that
Castanea pumila var. ozarkensis formerly was a member of the climax
community, but presently is one of the first species to regenerate
following a disturbance (e.g., clear-cut, prescribed fire). Paillet
(1991, p. 10; 1993, pp. 261-262) noted an area on the Ozark National
Forest that was cut 4 to 5 years previously that was full of broad
chinquapin crowns and the ground littered with burs from the summer's
nut crop.
In summary, we find that the information provided in the petition,
as well as other information in our files, does not present substantial
scientific or commercial information indicating that the petitioned
action may be warranted due the present or threatened destruction,
modification, or curtailment of habitat or range. However, we will
further investigate the potential threat of the present or threatened
destruction, modification, or curtailment of habitat or range in our
status review for this species.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
No information was presented in the petition, or is available in
our files, to indicate that Castanea pumila var. ozarkensis may warrant
listing due to overutilization for commercial, recreational,
scientific, or educational purposes.
C. Disease or Predation
Information Provided in the Petition
The petition cites two diseases that threaten Castanea pumila var.
ozarkensis populations:
(1) Ink disease, caused by Phytopthora cinnamomi, is known to
attack the root systems of all North American Castanea species.
Phytopthora cinnamomi spores spread through groundwater, and thus is
most prevalent in low-lying areas. The petition did not identify it as
an immediate threat because the current range of Castanea pumila var.
ozarkensis is restricted to upland areas of the Interior Highlands.
Phytopthora cinnamomi is prevalent in many areas of the Gulf Coastal
Plain, and the petitioner believes that this portion of Castanea pumila
var. ozarkensis' historic range is presently unsuitable for
[[Page 30317]]
occupation due to the disease infestation.
(2) Chestnut blight, caused by the fungal parasite Cryphonectria
parasitica, attacks the stems of all North American Castanea species
but is not directly pathogenic to the root system. Since its
introduction, chestnut blight has severely impacted Castanea pumila
var. ozarkensis throughout the Interior Highlands by causing the loss
of the majority of mature stems. The species continues to survive
because the root systems have remained intact and continue to sprout
new stems that are eventually killed by the chestnut blight.
An unpublished, non-peer-reviewed report written by the petitioner
described personal observations of Castanea pumila var. ozarkensis on a
portion of the Ouachita National Forest in LeFlore County, Oklahoma.
The report described the petitioner's assessments of the life
expectancy of blight-affected sprout clumps of various sizes with
assumptions of varying degrees of blight resistance. The report
concluded that based on observations, environmental factors also had
contributed to the decline of the species. The report also describes
the petitioner's assessment that factors such as genetic resistance and
early maturity of stems have not halted seed production of Castanea
pumila var. ozarkensis, at the evaluated sites. The petitioner
indicates that chestnut blight may not present an insurmountable threat
to the survival of the species.
Evaluation of Information Provided in the Petition and Available in
Service Files
We are not aware of any information to indicate that ink disease
poses a significant threat to Castanea pumila var. ozarkensis at this
time. On the other hand, information provided in the petition and in
our files does indicate that chestnut blight is widely recognized as
the dominant threat to Castanea pumila var. ozarkensis. Chestnut blight
was first noticed in American chestnut trees (Castanea dentata) in New
York City in 1904. Over a period of about 20 years, the blight spread
throughout the range of the American chestnut, reducing this important
forest tree to a multiple-stemmed shrub. The fungus enters wounds in
the bark and grows under the bark, eventually killing the cambium all
the way around the infected area. This results in the death of most of
the above-ground portion of the tree. After top-kill, sprouts develop
at the base of the tree from dormant buds. These sprouts grow, become
infected, and die, and the process is repeated (Anagnostakis 2000, p.
1). The blight affects all North American Castanea species, and its
effect on Castanea pumila var. ozarkensis was noted beginning in the
1940s.
Castanea pumila var. ozarkensis, like the American chestnut
(Castanea dentata), has sprout clumps that are capable of persisting in
the understory of established woodlands for many years without seed
production. Castanea pumila var. ozarkensis sprouts are released when
seed production is suppressed. In one Arkansas locality, the sprouts
experience rapid growth and produced seeds within a few years of
release (Paillet, 1993, p. 267). However, localities with fruit
production were increasingly rare by the 1970's (Tucker, 1983, pp. 9,
16). Tucker (1983, pp. 9, 16) could locate only two sexually
reproducing populations out of several hundred localities investigated
in the Interior Highlands from 1967 - 1983.
Castanea pumila var. ozarkensis also responds favorably to forest
thinning. Paillet (2002, pp. 1522, 1523) observed Castanea pumila var.
ozarkensis sprouts dominating the biomass of recent clear-cuts in the
Ozark Mountains of northern Arkansas. In the absence of competition,
Castanea pumila var. ozarkensis is often able to survive several years
until it becomes infected with the blight. It persists despite the
blight, mainly because of its ability to sprout new stems asexually as
opposed to sexual reproduction through fruit production. Sexually
reproducing stands were increasingly rare by the early 1970's (Tucker,
1983, pp. 9, 16), and it is plausible to conclude that even fewer
stands may persist via sexual reproduction two decades later.
Despite the shift in reproductive strategy and a shorter life span
for the stems, chestnut blight has not affected the distribution and
abundance of Castanea pumila var. ozarkensis in the Interior Highlands
of Arkansas, Missouri, and Oklahoma. Information in our files indicates
that Castanea pumila var. ozarkensis has degenerated to stands
consisting mostly of stump sprouts. There have been some isolated
localities in which sprouts have survived 5 or more years and produced
fruit post-blight infection but indications are that these sites have
become increasingly rare since the early 1990's. Tucker (1983, p. 25)
states that chestnut blight is responsible for the mortality of extant
sexually reproducing populations, reducing populations to primarily
asexual reproduction, and that sexually reproductive populations may
become extirpated.
We do not have sufficient information to substantiate the current
distribution and status of sexually reproductive populations to
determine whether blight infestation in Castanea pumila var. ozarkensis
will result in the extirpation of these populations, which would limit
all remaining populations to asexual reproduction. There also is no
data in the Service's files to predict what effect the loss of sexually
reproducing Castanea pumila var. ozarkensis would have on the survival
of the species. Therefore, we rely on data in our files related to
other Castanea species to use as a surrogate for comparison. Stillwell
et al. (2003, pp. 3-4) discuss several effects to Castanea dentata as a
consequence of chestnut blight, including from ecological changes and
the diminished importance of sexual reproduction on the amount and
distribution of genetic diversity in the species. First, the chestnut
blight significantly alters the ecology of Castanea species, which may
reduce the overall level of genetic diversity. Secondly, chestnut
blight may affect the distribution of genetic variance within and among
populations. This could occur by genetic drift from the reduced
population size or from the vegetative expansion of root collars, both
of which would tend to diminish genetic variance within patches.
Knowles and Grant (1981, p. 4, in Stillwell et al. 2003) and Mitton
and Grant (1980, p. 4, in Stillwell et al. 2003) present contrasting
information on long-lived trees and the general perception that more
heterozygous individuals are less variable and better adapted in
fluctuating environments. Many long-lived tree species show an excess
of heterozygosity suggesting that selection favoring heterozygotes is
relatively subtle and hence is more likely to have an effect over the
course of a long lifespan. Subtle differences in the performance of
genotypes may be magnified in importance as Castanea clones have aged
over the last 70 plus years and even relatively small fitness effects
may accumulate to have conspicuous effects on the genetics of
populations (Stillwell et al. 2003, p. 4).
The results of Stillwell et al. (2003, pp. 9-11) suggest that the
chestnut blight has had significant effects on the genetics of Castanea
dentata populations. They found that a slight growth advantage for
heterozygous genotypes has resulted in a profound excess of
heterozygotes within populations. Studies of different age classes
(seeds, seedlings, and stands of differing age) show an increase in
heterozygosity with increasing age within other tree species. The
difference observed by Stillwell et al. (2003, pp. 9-11) is that all
extant Castanea dentata
[[Page 30318]]
genotypes are more than 70 years old and many that succumbed to the
blight as mature canopy trees are much older. Therefore, as selection
favors a population of heterozygous individuals, there are no new
recruits to restore the population toward Hardy-Weinberg equilibrium (a
constant state of genetic variation in a population from one generation
to the next in the absence of disturbance). Prolonged absence of sexual
reproduction in Castanea dentata has resulted in a change in population
genetics.
The high mortality of Castanea dentata stems in conjunction with
near total elimination of sexual reproduction could have resulted in
the loss of some (mostly rare) alleles (Loveless and Hamrick 1984;
Leberg 1992 in Stillwell et al). It is not clear, however, whether this
slightly lower genetic diversity is a result of the blight
epidemic...Huang et al 1998 suggested that the low genetic diversity of
the American chestnut resulted in the high susceptibility to attack by
blight, rather than that the low genetic diversity was a direct
consequence of the blight pandemic, and that other Castanea species
with more diverse allozyme variation are less susceptible to epidemics.
In the absence of pre-blight genetic population structure, it is
difficult to make any definitive statement on changes in genetic
diversity due to the chestnut blight pandemic (Stillwell et al. 2003,
p. 10).
Summary to Factor C
Information provided by the petitioner and in our files indicates
that ink disease does not pose a significant threat now or in the
foreseeable future to the continued existence of extant Castanea pumila
var. ozarkensis populations. Information in our files supports the
petition's assertion that chestnut blight may pose a substantial threat
to the species and that chestnut blight is the greatest threat to the
continued existence of Castanea pumila var. ozarkensis.
While the personal observations cited by the petitioner of Castanea
pumila var. ozarkensis described on a portion of the Ouachita National
Forest are informative and useful in understanding the extent of
chestnut blight occurrence in the western extreme of the species'
range, the information does not indicate any overall change in the
species' range, distribution, or abundance in spite of the continued
existence of disease threats that have been acknowledged in the past
and continue at present. However, information in our files indicates
that chestnut blight has adversely affected the biology (sexually
reproductive populations are greatly diminished from pre-blight status)
of Castanea pumila var. ozarkensis and other Castanea species in the
past 70 years since infestation occurred and may threaten the
reproductive status and genetic diversity of extant populations. While
the overall level of genetic diversity within and among populations of
Castanea pumila var. ozarkensis is not well understood, there is
genetic information on other Castanea species to suggest that
ecological changes and the diminished prevalence of sexual reproduction
may reduce the amount and distribution of genetic diversity.
In summary, the chestnut blight has disrupted the life cycle of
Castanea pumila var. ozarkensis by reducing the sexual reproduction to
isolated areas, forcing the species to survive mainly by asexual
reproduction. The blight has threatened the reproductive status and may
threaten the genetic diversity of extant populations. We find that the
information provided in the petition, as well as other information in
our files, presents substantial scientific or commercial information
indicating that the petitioned action may be warranted due to disease
from chestnut blight.
D. Inadequacy of Existing Regulatory Mechanisms
No information was presented in the petition, or is available in
our files, to indicate that Castanea pumila var. ozarkensis may warrant
listing due to the inadequacy of existing regulatory mechanisms.
E. Other Natural or Manmade Factors Affecting the Species' Continued
Existence
No information was presented in the petition, or is available in
our files, to indicate that Castanea pumila var. ozarkensis may warrant
listing due to other natural or manmade factors affecting the species'
continued existence.
Finding
On the basis of our evaluation of the information presented under
section 4(b)(3)(A) of the Act, we have determined that the petition
presents substantial scientific or commercial information indicating
that listing Castanea pumila var. ozarkensis throughout its entire
range may be warranted due to disease or predation (Factor C).
Following a review of the information presented in the petition and
readily available in our files, we have determined that substantial
information was not presented or available that suggests listing may be
warranted due to the present or threatened destruction, modification or
curtailment of habitat or range (Factor A). The petition did not
include any information related to Factors B, D, and E. Because we have
found that the petition presents substantial information indicating
that listing Castanea pumila var. ozarkensis may be warranted, we are
initiating a status review to determine whether listing Castanea pumila
var. ozarkensis under the Act is warranted.
The ``substantial information'' standard for a 90-day finding
differs from the Act's ``best scientific and commercial data'' standard
that applies to a status review to determine whether a petitioned
action is warranted. A 90-day finding does not constitute a status
review under the Act. In a 12-month finding, we will determine whether
a petitioned action is warranted after we have completed a thorough
status review of the species, which is conducted following a
substantial 90-day finding. Because the Act's standards for 90-day and
12-month findings are different, as described above, a substantial 90-
day finding does not mean that the 12-month finding will result in a
warranted finding.
References Cited
A complete list of references cited is available on the Internet at
http://www.regulations.gov and upon request from the Arkansas
Ecological Services Field Office (see FOR FURTHER INFORMATION CONTACT).
Authors
The primary authors of this notice are the staff members of the
Arkansas Ecological Services Field Office (see FOR FURTHER INFORMATION
CONTACT).
Authority
The authority for this action is section 4 of the Endangered
Species Act of 1973, as amended (16 U.S.C. 1531 et seq.).
Dated: May 19, 2010.
Gregory E. Siekaniec,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2010-13069 Filed 5-28-10; 8:45 am]
BILLING CODE 4310-55-S