Upon entering Wilson's Promontory
I was intrigued by the fact that the right side of the road was quite
black from fire and the left was unscathed. Simon later told me it was
deliberately set and proceeded to tell me what he knew of controlled
burning in this area. I was impressed that I could virtually see research
being done, but even more amazed to discover later on that it was being
done by some of my peers-Melbourne Uni Botony students. I wanted to
learn more about fire management and how it will effect the Prom, so
I did a little research.
Aborigines have inhabited Wilson's
Promontory for at least 6000 years and they used fire for many purposes
including amusement, signaling, to clear ground to facilitate travel,
hunting, regeneration of food for both humans and kangaroos, and expanding
human habitat. It is estimated that fire swept through this area annually
at this time. The early 1800's brought the arrival of white European
colonizers who exploited the land via fishing, sealing, whaling, mining,
logging and clearing the forest in order to graze animals. They did
not permit natural fires to run their course and surely did not light
any themselves, nor would they allow the Aborigines to perform what
they called 'firestick farming' on their property in case the fire escaped
and burned down some crop land.
The Prom was first reserved
in 1898 but exploitation continued to the extent that the park was closed
and became an army training center in 1941. In 1951 a fire burned down
75 percent of the park, the exact occurrence the Aborigines were trying
to avoid by lighting many small, low-intensity fires. Needless to say,
the landscape of the Prom and the whole east coast of Australia has
changed dramatically from what the journals of Joseph Banks describe
as he sailed up the coast in 1770. In the past fifty years a noticeable
change has occurred in Wilson's Promontory. In the 1960's Leptospermum
laevigatum (L. laevigatum) migrated from the tall shrublands
on the landward side of the coastal dunes to the inner heathlands, creating
a canopy that suppressed the natural heath beneath it. Similarly in
the 1970's Kunzea ambigua (K. ambigua) invaded the
heaths as it moved from the elevated granite outcrops inland from the
heaths. It also was choking out the native vegetation, resulting in
a decrease in species diversity and richness. In 1990 a research project
commenced via the collaboration of The Department of Conservation and
Natural Resources and the School of Botany at Uni Melbourne. Today the
project is hosted by the School of Botany and Parks Victoria. The purpose
is to test the ability of the heath to revert to its more natural state.
Given that both invading species are obligate seeders and are killed
by fire, it was proposed that two fires would eradicate the invading
species and allow the native flora to flourish.
Quadrants containing the invading
species were demarcated and burnings took place in both 1991 and 1999.
Some were burned both years, others were only burnt once, and a control
site was left untouched. This year was the eleventh year that data has
been collected at these sites. L. laevigatum and K. ambigua
were supposed to be eradicated after the two successive burns, but the
data from this year does not definitively show this. In most plots the
species have at least one to five percent canopy cover, not quite dominating
but definitely not eliminated. However, the number of native species
has increased overall, utilizing their barren native soil created from
the burns. It's hard to predict whether or not the invading species
will continue to be held in check or increase in canopy cover and density
over time.
Another research project
being conducted by Chesterfield et al. studied the impact of grazing
on grassland composition on the Yanakie Isthmus of Wilson's Prom. In
their studies they excluded natural grazers (kangaroos, rabbits, and
wombats) from test sites in areas where well-grassed woodlands were
converted to closed shrub due to a serious L. laevigatum invasion.
They concluded that such areas would revert to a predominately indigenous
plant population within four years if all herbivore predators were controlled,
giving the native species the ability to flourish and exclude the introduced
species. It's implementations could be difficult and detrimental to
the aesthetics of the park because it would probably require extensive
fencing; though the fences would only be needed for a relatively short
period of time, hence it could be a good long term solution. This novel
idea could also be used in conjunction with burning as a method of invasion
control. Reducing the amount of grazing would ensure that there's enough
biomass for burning and that, after the burn, the herbivores won't consume
all of the new growth.
Although I'm not a botany
major and didn't understand all of the management theories I read about,
I learned a lot in the bit of research I did. I admit that I was surprised
to learn that the green dense heathland that most Prom visitors think
is healthy and aesthetically pleasing is actually very detrimental to
the park. My generation has been taught the Smokey the Bear mentality:
that fire is bad, very bad. It's hard to change this mind set, but I
noticed there was mention of this research project in the Prom brochure.
The more publicity it gets, the more people will understand and be patient.
Unfortunately the Prom has a long way to go before it's back to its
natural state, and it will probably look worse before it looks better,
but I'm relieved to know that work is being done and that one day people
will get to see Wilson's Promontory as the Aborigines did.
