So long as we regard a
tree as an obvious thing, naturally and reasonably created for a giraffe to
eat, we cannot properly wonder at it. It is when we consider it as a prodigious
wave of the living soil sprawling up to the skies for no reason in particular
that we take off our hats, to the astonishment of the park-keeper. – G.K.
Chesterton
[Some gum nuts and blossoms of Western Australia] |
There is much Chestertonian
astonishment to be had in Western Australia, particularly in spring. That such
poor soils can send “sprawling up to the skies” such a variety and beauty of forms
and flowers is truly astounding.
There’s a metaphor in there,
to be sure. But leaving that and metaphysical matters to whisper from the
wings, why should Western Australia’s flora be so astonishing? Isolation is one
reason. Long ages of separation from other parts of Australia have given the
flora of WA time and space to deal with the difficult climate and soil conditions
in their own unique ways.
The age and relative
stability of the land has helped too. The glaciation, tectonic movements and
other earth shattering episodes of the east have largely left the west
unscathed. For perhaps 250 million years the west has known the kind of
stability that has allowed its plants to develop and adapt successfully to nutrient poor
soils and often dry conditions.
The very richness of species
– 13 000 and counting – adds its own competitive pressure. Species push to
outdo each other in the race to attract the relatively low number of
pollinators, be they birds, invertebrates or mammals.
[Spring in karri and marri forests, WA] |
Adaptable as it is, the
west’s amazing flora is under threat from many quarters, most of them human in origin.
Land clearing, salination, climate change and inappropriate fire regimes are
all obvious and potent threats. A less visible but dire threat comes from a
fungus-like pathogen called Phytophthora
cinnamomi. Known in the west as dieback, or cinnamon fungus, it is spread in
soil and through water and mud. It attacks the root systems of some species –
and not others – causing death in susceptible species. In the west that’s 40%
of all native species. Boots, camping gear, vehicle tyres and earth-moving
equipment are some of its major means of spreading. Once established, it cannot
be erradicated.
[Spring blooms in Western Australia] |
As we drove through the
south-west, two things were obvious. One was the incredible number of four
wheel drives, seemingly more than 50% of all vehicles. While most were probably
not genuine off-roaders, the potential for spreading die-back by that means
alone looks frightening.
The other obvious thing was
that we could not, at a glance, see the effects of dieback. But they are there:
there in the displacement of the susceptible species by other species; there in
the slow disappearence of susceptible species; there in the slow spread of
dieback from infected areas to uninfected areas.
[More spring blooms in Western Australia] |
Thankfully we can do something to keep the threat to a minimum, bearing in mind that dieback
is a menace in many parts of Australia. We can become hygience conscious with
our boots, our vehicles, and our camping equipment. And we can be aware of when
we are moving into or out of a dieback infected area. That way we can maintain the
park-keeper’s – and our own – astonishment at these wonderful, free floral gifts.
No comments:
Post a Comment