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It's up to us... Fire Safety Publications About the Mendocino County Fire Safe Council About the Community Wildfire Protection Plan
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How sweet furze became Gorse the Invader is a story
of humans and the land, where settlers carried valued
plant seeds to their new homes with unintended results.
The evergreen shrub, gorse (Ulex europaeus), was
introduced by 19th century immigrants to the New World,
Australia, New Zealand and elsewhere and it soon
escaped cultivation. Today, it is one of the top 100 worst
invasive species worldwide according to the World
Conservation Union (ICUN). Also called furze and whin (and many other names),
gorse is native to central and western Europe where it is
often a dominant species in fire-adapted heathland plant
communities. Harsh climate, poor soils, native insects,
as well as grazing and burning practices combine to
contain gorse. For example, in Wales: “A good battering
by the winter gales keeps the gorse in check and leaves
the soil suitably thin and salt-stung for the special plants
of these rocky slopes”. Gorse is valued in its native lands as a ‘living fence’
where it is planted in hedges to control livestock. It is a
legume that is used as fodder, as fuel, and as a spiny
nurse plant to protect young trees. It improves low
fertility soils and is a soil stabilizer. Soap is made from
its ashes and it is a dye plant. The flowers make a pickle
and they are used to flavor beer and whiskey and to
make gorse wine. Gorse provides pollen for insects
(it’s bee pollinated) and protective habitat for wildlife. In the mid-1800’s gorse was taken to New Zealand and Australia for sheep forage and hedgerows and by 1900 was declared a noxious weed in these countries. It has naturalized in temperate mostly coastal areas throughout the world (including Chile and Sri Lanka), where it is an unmanageable nvasive costing millions of dollars each year to combat. Gorse was introduced to the eastern US in the early
1800’s but it never became extremely invasive.
However, on the West coast, where it was introduced
in the mid-1800’s as a hedge plant and as forage,
environmental conditions were such that gorse
successfully colonized areas in Oregon, California,
Washington, and Hawaii. Recently, it has invaded British
Columbia where ten percent of Vancouver Island is now
infested with gorse and broom. In California, gorse occurs in coastal counties from Santa Cruz to Del Norte and in the foothills of the northern Sierra Nevada. In Mendocino County, gorse has an unrelenting grip on the lands in and around the town of Caspar. “The legend of gorse's arrival in Caspar has several
versions, but in every one, gorse escapes from its
keepers and takes over acres of previously lovely
rangeland and bluff. Some diligent stewards have
kept gorse at bay, but they will tell you that the cost
of freedom from gorse is constant vigilance!” Gorse currently infests hundreds of acres within and bordering Caspar with much of this land owned by the State of California and managed by State agencies who are struggling to successfully control the spread of gorse on Jughandle State Reserve and on the Caspar Headlands. According to Marc Hoshovsky1 “Gorse is a successful
invasive plant because it grows on a variety of soil
types, fixes nitrogen, and may impoverish soil of
phosphorus. It produces copious amounts of heat-
tolerant seeds with long-term viability, and regenerates
rapidly from seeds and stumps after disturbances such
as brush clearing or fires…seeds may remain dormant
yet viable in the soil up to thirty years, with reports
of up to seventy years” . Hoshovsky1 notes that ”Gorse may be slow in becoming established and spreading, but where it gains a hold, there are few other plants that will so completely dominate an area. Besides being a significant fire hazard, it can successfully outcompete native plants.” This plant outcompetes humans! Land managers throughout the world have battled gorse the invader for over 100 years with limited success. There is a lot of information available on what has been tried, what seems to work, what not to do. Stuart Tregoning, whose family settled in Caspar
during the 1860’s has experience with various gorse
management strategies, including the use of fire and
herbicides. In Stuart’s opinion: “The only way to get rid of it is to
remove it mechanically. There is no simple approach
that doesn't involve a lot of work. My neighbor Ralph
Eagle and I developed a mechanical system of mowing
and tilling that, within a few years, encourages the
grass to dominate… In another interview with Stuart
and Caspar resident Caroline Schooley, also a long-time
gorse fighter, they reiterate: ”What really works…is
cutting, plowing, and perseverance” Currently, the California Department of Parks and Recreation is removing some of the gorse infestation at Jughandle State Reserve. Gorse thickets have been bull dozed into piles for burning later in the season when there will be less danger of fire spreading. Gorse is exceedingly flammable because volatile oils
are concentrated in the spiny foliage and branches.
The story of the Bandon Fire of 1936 in Oregon inspires
uneasiness because of its resemblance to the town of
Caspar. An Irish immigrant introduced his favorite furze
hedge to Bandon in1873 and 63 years later the plant
infested the town to such a degree that firefighters were
unable to save the town when a nearby wildfire ignited
the gorse. Gorse is blamed as the primary fuel source
in the devastating fire that killed 10 people. From the Oregon History Project: “Remembering his
childhood visits to Bandon in the early 1930s, historian
Thomas McClintock wrote that gorse filled the spaces
between the town’s scattered buildings…Bandon
resident D.H. Woomer told a Coos Bay Times reporter
shortly after the fire: “That Irish hedge was the worst
thing—when the fire hit it right across from my house,
the flames shot up high into the air. It was just as though
there had been gasoline poured on the fire”. Ironically,
just a week before the fire Frank P. McWhorter, the
state plant pathologist, had warned Bandon’s residents
The gorse seed weevil (Exapion ulicis) and gorse spider mite (Tetranychus lintearius) were introduced as biological controls into the United States, the weevil in 1953 from France and the spider mite in 1994. Neither of these species were USDA approved biocontrol insects according to Hoshovsky. In addition to the seed weevil and spider mite, in Hawaii,
a moth, a gall-forming weevil, a thrip and a rust fungus
have been introduced to control gorse. Seven biocontrol
species have been introduced into New Zealand. (http://www.hawaiiag.org/hdoa/newsrelease/00-01.htm) Goat grazing is effective in checking gorse although goats are best used to graze young regrowth after the removal of mature thickets. At least two years of grazing is required to significantly reduce gorse (Hoshovsky). Gorse is difficult to kill with a single application of herbicide and spraying alone is not a solution for control according to Hoshovsky1 and others. Combination methods are recommended, first mechanically removing plants followed by herbicide applications ("cut and paint" use of glyphosate) or grazing. Management efforts must be ongoing in scope in order
to be successful, due to the longevity of buried seeds.
In addition, gorse seed can travel extended distances
on contaminated machinery. Significant long-distance
dispersal in Australia occurred when seeds were carried
on vehicles and machinery and in topsoil and fill. Caspar residents have established a Gorse Campaign
link on the CasparCommons website where they post
gorse resources, including fire prevention resolutions,
invasive species information and gorse removal
techniques (http://www.casparcommons.org). Gorse was recently found in Ukiah and plants are
growing on property near Point Arena. If you know of
additional populations please contact Tara Athan,
Mendocino Coast Weed Management Area,
(707)
485-1198 or Source: (also see citations in text) Additional information: Young, S. 2003. Exploring alternative methods for
vegetation control and maintenance along roadsides. |
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