How can you
tell if a plant is native in the bush?
You can often tell if a plant is
native, without knowing its name, via two key characteristics:
-
Sclerophylly
-
Growth habits
Sclerophylly is an
adaptation to arid conditions and, since Australia is largely semi
arid to arid, most native plants show this adaptation. It takes the
form of stiff waxy or leathery leaves (Eucalyptus and Acacia),
greatly reduced leaves (Acacia, Thryptomene) and small flowers or
any combination of the three. All these adaptations greatly reduce
water loss from the leaves in dry conditions. There are exceptions
to this general rule such as Alyogyne huegelii, that has lobed
leaves with a greatly reduced surface area but unusually large
flowers, and many plants from the sub-tropic coastal areas, that
often have quite large but waxy or leathery leaves.
The growth habits of
native plants, that are adapted to Australia's generally shallow and
impoverished soils, are fundamentally different to plants that are
adapted to deep rich top soils, notably many European plants.
Due to Australia's poor soils,
and also to bushfires, a multitude of slightly different ecological
niches are created across our landscapes. This multitude of
ecological niches is filled by a multitude of native plants that
specialise in that particular niche thus resulting in Australia's
incredibly high plant biodiversity.
Hence, with the exception of
areas disturbed by grazing agriculture, you very rarely see any
particular native species dominating large areas to the exclusion of
nearly everything else. You will see a few species dominating a
limited area but you will always find a highly varied collection of
other species growing among them.
In contrast, European landscapes
have much lower plant biodiversity and large areas are often
dominated by a small number of very invasive species. When nutrient
levels in our soils is raised due to fertiliser application etc, the
balance is often tipped in favour of the exotic pasture grasses and
garden plants which then displace most of the native plants and
dominate large areas as they do in Europe etc.
Do I need jute mat?
Jute mat is primarily designed to
suppress weeds on steep embankments that cannot hold mulch and along
the edge of water ways where mulch is likely to be washed
away.
But there are other garden
situations where it can be useful. For example you can lay down a
nice thick layer of tree mulch to suppress weeds, cover this with
jute mat and then spread a thin layer of decorative pebbles. The
jute mat will prevent the stones from mixing with the underlying
mulch and spoiling the effect.
The jute mat and mulch will break
down over time and, if you haven't got thick ground cover by then,
you will need to scrape back the pebbles, spread a fresh layer of
tree mulch, and replace the pebbles.
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