I went for a walk in the closest patch of wild scrub/forest from my place. 4 kilometres. It was mined for gold 170 years ago but is probably a bit too difficult to turn into a residential area. It is also an area that speaks loudly of introduced plants.
Most of the trees you can see are native – at least in this photo.
But here is a Monterey Pine (Pinus radiata) from California. This tree is grown in huge plantations in Victoria and South Australia and supplies the building industry with most of its construction timber.
- It is a threat to Mediterranean ecosystems worldwide and in Australia it invades a wide variety of open dry ecosystems.
- Seeds are equipped with wing like structures and can travel up to a km on the wind as well as being dispersed by native wildlife such as Yellow Tailed Black Cockatoos.
There is a small acacia seedling that might survive next to the pine.
On the forest floor the evidence of introduced plants is extreme.
In the bottom right hand corner is some Spanish Gorse (Ulex europaeus) and on the left is Montpellier broom (Genista monspessulana): Lauded in English and American Garden guides as one of the most reliable shrubs for hot and dry sites gorse is a major pest in Australia and New Zealand. It was introduced to Australia as a hedge plant in the early 1800s, but, like cats and cactus and pigs and donkeys and camels and a host of other things that were considered benevolent, it quickly spread out of control. In Tasmania gorse has rendered many hectares of land in the Midlands useless for grazing. It is one of New Zealand’s worst weeds. Its nitrogen-fixing ability means that it tends to inhabit areas with poorer soils where other plants find it hard to survive.
A lot of work, world wide, to find a biological method of controlling the gorse has been tried. But the task is huge and has shown little progress to date.
It also makes a great web building site for small spiders.
That’s enough of me going on and on. Just enjoy the rest and if you see an introduced plant then you are welcome.
The butterfly below is the inventively named Common Brown (Heteronympha merope).