Final Comprehensive Conservation Plan - U.S. Fish and Wildlife ...

Hakalau Forest National Wildlife Refuge
Comprehensive Conservation Plan
Asplenium peruvianum var. insulare is present on East Maui and Hawai„i Island between 5,413-
7,218 ft (Palmer 2003). The species historically occurred on the upper slopes of Mauna Loa above
Kipuka Ahiu, Pu„u Wa„awa„a on Hualālai, near Hilo, as well as at Kalaieha, Laumai„a, Keanakolu,
and „Umikoa on Mauna Kea (USFWS 1998b). Currently, it is known at Pu„u Huluhulu, Pōhakuloa
Training Area (PTA), Kūlani Correctional Facility, Keauhou, the Mauna Loa Strip Road in Hawai„i
Volcanoes National Park, Kapāpala Forest Reserve, Ka„ū Forest Reserve, and the summit area of
Hualālai. The largest population occurs at PTA. It is comprised of approximately 200 individuals
within 9 subpopulations (USFWS 1998b). The population at the Kapāpala Forest Reserve was
comprised of 300 mature individuals in 2003 (Federal Register 2003b). It is also found on the KFU.
On Maui, A. peruvianum var. insulare was recently reported in the Hanawī Natural Area Reserve
(NAR) and has been previously sited on the north slope of Haleakalā and Kanahau Hill (USFWS
1998b).
The species grows almost exclusively in dark, moist environments such as rock crevices or in lava
tube openings (Palmer 2002) within montane wet, mesic, or dry forests, as well as subalpine dry
forest and shrublands (USFWS 1998b). The fern prefers areas receiving between 48-100 in per year.
It is often associated with mosses and liverworts (USFWS 1998b).
Palmer (2002, 2003) proposes that morphological and habitat differences within the species suggest
Asplenium peruvianum var. insulare may be divided into two taxa. One form is delicate,
nonproliferous, longer, narrower, and light green in color. This form is often found in lava tubes
openings. In contrast, a coarser, proliferous, shorter, wider, darker green form is usually found in
more open areas (Palmer 2002, 2003).
Critical habitat is designated on both islands where Asplenium peruvianum var. insulare is present.
On Hawai„i Island, the critical habitat area encompasses 2,241 ac in the Pāhala watershed, which is
the southernmost critical habitat within the species‟ historical range. In addition, two populations
were given critical habitat designation on Maui (Federal Register 2003b).
Habitat degradation and browsing by sheep and goats are identified as the main threat to this species
existence. Cattle may also negatively impact A. peruvianum var. insulare. Nonnative fountain grass
is known to invade A. peruvianum var. insulare habitat. Some populations are also threatened by
military operations and fires that result from these operations, as well as construction activities
(USFWS 1998b).
The downlisting criteria established in the Recovery Plan for Four Species of Hawaiian Ferns
(1998b) requires 5-7 populations on both islands that are naturally reproducing, stable or increasing
in number, and secure. Each population must have a minimum of 300 mature individuals for
5 consecutive years. In order to delist the species, a total of 8-10 naturally reproducing, stable
populations must be documented on both Maui and Hawai„i Island. Each population must contain at
least 300 mature individuals per population for 5 consecutive years.
4.9.2 Clermontia lindseyana
Clermontia lindseyana is an endemic, small tree that was listed as endangered in April 1994. Species
within this genus are often referred to by the Hawaiian name „oha wai. The species grows between
8.2-20 ft in height and can occur as an epiphyte or terrestrial dweller. The oblance shaped leaves are
dark green on the upper surface and pale green to purple on the underside. Clermontia lindseyana can
Chapter 4. Refuge Biology and Habitats 4-59