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

Scientific Name
Hakalau Forest National Wildlife Refuge
Comprehensive Conservation Plan
Common &
Hawaiian Name(s)
Status Hakalau
Unit
Pipturus albidus māmaki, waimea E X
Urera glabra ōpuhe, hōpue E X
Woodsiaceae
Cystopteris douglasii -- E* X
Status: E = Endemic; I = Indigenous; * = Species of Concern (former candidate endangered
species, or species otherwise considered rare by refuge officials).
Sources: Stone et al. 1991, USFWS 2002b, USFWS 2008.
Kona
Unit
Since humans came to the islands, populations of Hawai„i‟s native vegetation have greatly declined.
Native plant taxa in Hawai„i evolved on the islands without common plant defenses such as
poisonous compounds, prickles, and spines (Lindqvist et al. 2003). The absence of these defenses
leaves native plants especially vulnerable to ungulates and other nonnative herbivores. In addition,
introduced species are better adapted to fire than native plants. Although some native species appear
to be tolerant (koa, māmane, naio, „a„ali„i, „ōhelo), no native Hawaiian plants require fire in order to
regenerate (Smith and Tunison 1992, USFWS 1996, USFWS 2002a). More recently, competition
from nonnative vegetation has suppressed regrowth or success of native plants. Native plant species
richness and cover decreased with elevation (Barnett and Simonson 2008).
In the pasture areas of the HFU, native plant populations were historically altered by grazing,
logging, and possibly fire, eliminating the native seed bank. At lower elevations the native seed bank
was reduced because of continued cattle grazing and pig disturbance for well over 100 years (Jeffrey,
pers. comm.). Similarly, the KFU has been exposed to grazing, browsing, and pig disturbance;
however, because the forest canopy is intact and some rare native plants located in skylights on the
unit have been protected from ungulates, a seed bank for most species still exists.
Since 1987, the Refuge has been conducting extensive reforestation research, ungulate control,
nonnative plant control, and native plant and tree planting activities to help facilitate natural
regeneration of native plant communities and natural processes of succession at the Refuge. Over
400,000 native trees are planted in mauka to makai corridors to provide foraging cover, and nesting
sites for native forest birds on Mauna Kea. The planting restoration effort is largely concentrated in
the upper portions of the Refuge 5,500 - 6,600 ft as these areas have been the most heavily disturbed
by ranching and other human activities (USFWS 1996b).
Between 2006-2007, roughly 122 ac of upland habitat was restored on the HFU (USFWS 2006,
2007). Supplemental funding and supplies for restoration have come from Natural Resources
Defense Council (NRDC), Hilo Rotary Club, American Forestry Association, Waimea State Tree
Nursery, and DOFAW. Volunteers are an integral part of the effort, donating over 7,000 personhours
annually. These volunteers collect seeds; plant and fertilize native species; assist with
monitoring and surveys of flora and fauna, the annual open house, and nonnative weed control
(USFWS unpub.). Exclosure studies have shown that rapid regeneration of native species, especially
koa and „ōhi„a, does occur in the absence of ungulates where a seed bank exists (USFWS, unpub.
data).
Chapter 4. Refuge Biology and Habitats 4-75