 
The purpose of the Pu'u Anahulu Fuel Management Project is to evaluate
the effectiveness of fuel management techniques in reducing the occurrence
of wildfire in wildland-urban interface areas and dryland ecosystems
in North Kona region on the island of Hawaii. The project will include
the installation, evaluation, and demonstration of series of grazing,
herbicide, and prescribed fire treatments to determine the best methods
to proactively manage wildlife within the region. This project will
draw from the combined experience of local ranchers, fire fighters,
and land managers to apply treatments within the project of study area.
Actual fuels management studies directly involving the local resource
managers will provide an accessible demonstration of some techniques
available to manage wildfire fuels.
Numerous wildland fires have occurred in the larger landscape that encompasses
the study site (DOFAW
records 2001). Most fires in the area occur during the late summer and
fall between the months of July and November. The vast majority of these
wildfires have originated along Mamalahoa Highway. The source of ignition
of most of these fires is undocumented, however accidental ignitions
and arson are suspected as the primary sources.
Wildfires in this area are carried by alien grass fuels
which ignite readily and dry quickly, thereby facilitating rapid fire
spread particularly under windy conditions. The predominant alien grass
that carries these fires is fountain
grass (Pennisetum Setaceum), native to northern Africa and
Mediterranean coastal areas. With exception to a few short-lived native
shrubs like 'ilima
(Sida Fallax) and a'ali'i
(Dodonea Viscosa), most native trees and shrubs that once
dominated this area appear intolerant of fire and do not resprout or
establish from seed following wildfires. This cycle of grass invasion,
frequent fire and woody plant mortality has proven to be self-perpetuating.
The resulting vegetation structure is one of a savanna or grassland,
vegetation type dominated by exotic tall grasses - known to fire scientists
as quick-drying, easily ignited flashy fuels that complete their combustion
within one hour or less - also referred to as 1-hour fuels. It is these
light, flashy fuels that easily ignite and carry wildfire across the
landscape. Reduction of these 1-hour fuels in areas of highest ignition
probability, that is along roadsides such as Mamalahoa Highway, is the
focus of this project. It is anticipated that the existing native seed
bank may respond differently in each of the 12 treatments. For this
reason, native species regeneration will also be monitored over the
two year period following the treatment.
The Pu'u Anahulu study site
encompasses 240 acres of roadside lands
on the NW slope of Mauna Loa. The site is bounded along its lower edge
by the Mamalohoa Highway (State Hwy. 11), along its upper edge by an
unimproved fire break road that parallels the highway at distance of
500 - 1500 ft. upslope, by the South Kohala/North Kona district boundary
on the NE, and by the 1859 flow to SW. The site occurs between 2,165
and 2,624 ft. elevation on predominantly Mauna Loa volcanics that range
in age from 1,500 to 5,000 years old. Climate of site was likely once
wetter than it is now, the change likely a result of human-induced alteration
of the vegetation structure and associated microclimatic variables (precipitation,
surface solar radiation, surface wind speed, and relative humidity regimes),
and changing global climate.
Elsewhere, fuels management techniques have been successfully developed
to reduce the probability of ignition and/or rate of spread of wildfires
that occur (Davidson, 1996). In Hawaii, cattle ranching, some wildlife
management practices, and ecosystems restoration techniques have all
contributed to the reduction of Pennisetum,
resulting in reduction of 1-hour fuel. Pu'u Waawaa Ranch, the original
Pennisetum
introduction site, now has advanced invasion, yet retains tree cover
and is a popular gamebird and mammal hunting unit. Over the past 40
years the ranch has utilized a combination of stocking rate manipulations
and a grades fire break to reduce fuel loads and fire frequency. The
lower fuel loads within the ranch resulting from a cattle grazing and
grazing and browsing by feral sheep and goats (wildlife), may be responsible
for near absence of non-roadside-ignited fires within the Ranch lease
area and an overall low occurrence of large catastrophic wildfires.
As a result, within the ranch occur many of the remaining patches of
native dry forest below 4,000 ft.
While grazing appears to be effective means of controlling fine
fuels at a large scale, assessments of other fuels management techniques have
not been conducted in Hawaii. Prescribed burning, the technique most commonly
used to manage wildfire fuels by federal land management agencies such as
the Forest Service and the Bureau of Land Management, has limited use in Hawaii
by Parker Ranch to control gorse invasion at Humuula and by the US Army to
control fuels and validate fuel models on their installations on Oahu and
Hawaii islands. Apparently, the combination of grazing and herbicide have
not been used to suppress fuel build up in Hawaii.
[ Project Description | Project
Leaders | Approach | Anticipated
Impacts | Photo Albums | Links
| Contact Info ]
Best viewed with Internet Explorer 5.0+ or
Netscape Communicator 6.0+.
Last updated on
|
