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

Species, Species
Group, or Habitat
Phyllostegia
racemosa
Hawaiian Name,
Common Name
No common
name
Hakalau Forest National Wildlife Refuge
Comprehensive Conservation Plan
Supporting Habitat Type(s) and/or
Specie(s)
Montane wet „ōhi„a and mesic
koa/„ōhi„a forest 5
Phyllostegia velutina No common Montane wet „ōhi„a and mesic
name
koa/„ōhi„a forest 5
n/a
Portulaca
sclerocarpa 3 n/a
Po„e Dry koa/„ōhi„a/māmane forest
Montane wet „ōhi„a forest, mesic n/a
Sicyos macrophyllus „Anunu
koa/„ōhi„a forest
Silene hawaiiensis 1
No common
n/a
Notes:
name Dry koa/„ōhi„a/māmane forest
* Species appear in taxonomic order.
** Habitat types follow Jacobi et al. (1989).
*** Species appear in alphabetical order.
1
Specimen found on Refuge currently pending verification.
2
No individuals are known from the Refuge.
3
Plants known from adjacent area but not currently known from Kona Forest Unit.
4
Critical habitat has been designated for these species at Kona Forest Unit.
5
Critical habitat has been designated for these species at Hakalau Forest Unit.
4.3 Habitats
Life-History
Requirement(s)
Both the HFU and KFU are montane communities located between 1,640-8,900 ft. This community
type is further divided based on annual rainfall; montane dry communities receive less than 48 in per
year, montane mesic communities receive between 48-100 inches of rainfall per year, and montane
wet communities are defined as areas receiving more than 100 inches annually (Wagner et al. 1999).
These plant communities are then defined based on the vegetation cover. For example, a community
that has greater than 25 percent of the upper vegetation layer covered by trees is defined as a forest
(Wagner et al. 1999).
On the Island of Hawai„i, montane forests have been severely altered by a variety of factors,
including land use changes and invasive species introductions. In particular, introduced mosquitoes
transmit avian diseases that have resulted in declines in native bird populations and ungulates have
removed native plant species. Conservation and restoration efforts are needed to improve habitat
conditions at both units of the Hakalau Forest NWR.
4.3.1 Hakalau Forest Unit
The habitats at the HFU are defined according to gradients of elevation, temperature, and rainfall. In
addition topography, soils, and geological substrate play a role in influencing these zones. The
montane habitats at HFU have been transformed by years of cattle ranching and logging, creating
isolated areas of relatively undisturbed forest and highly modified open woodland (VanderWerf
1993). The native species dominated habitats within the HFU are described below, from lowest to
highest elevation as well as several nonnative species dominated communities, including stands of
eucalyptus and sugi pines, as well as former pasture lands that are still dominated by nonnative grass
species. Figure 4-2 shows the main vegetation types found on the HFU.
Chapter 4. Refuge Biology and Habitats 4-5
n/a