Wednesday 30 January 2008

Lerderderg Gorge: Mackenzie's Flat


Lerderderg Gorge State Park is less than an hour's drive from home but I'd never been there. (I've asked this question before but I need to ask it again — what on earth have I been doing with my time?). Anyway, to redress this appalling lack, I headed out to the Gorge last Friday with my botanist friend and we had a look at all of the plants and some of the animals.



The SP covers more than 14,000 hectares of eucalypt woodland. At the southern end, it's dry and rocky, with a number of rare and endangered plants. The dominant trees are blue manna (Eucalyptus globulus) and manna gum (E. viminalis) along the river and red box (E. polyanthemos) on the ridges. At the northern end, the tall forest is mostly messmate (E. obliqua) with narrow-leaved peppermint (E. radiata). In between is an interesting sequence of box and box – ironbark woodland, which seems to change rapidly from one type to the next.

The Lerderderg River rises near Blackwood and cuts a concertina of meanders through the hills until it joins the Werribee River on the coastal plain. The gorge is Lower Ordovician sandstone and mudstone shot through with veins of quartz. The sediments were laid down about 470 million years ago in a shallow sea.



Since then, it's been tilted and turned and uplifted by a succession of faults ...

... but has survived all that geological manhandling in remarkably good nick.

And there's gold in them thar hills.

Koalas are common here but we didn't see their furry arses wedged in the manna gums. This seems to be the pattern. I'm beginning to suspect they're hiding from us. Neither were echidnas or kangaroos terribly obvious but the wombats had made their presence felt. Well, one wombat, which had marked its territory with great enthusiasm. Like lots of other mammals, they warn off intruders with judiciously placed poo. Wombats take great care with the location, preferring to leave their boundary markers on logs and stones. How they manage some of those sites is difficult to comprehend. They're not the most acrobatic of animals … but maybe they have hidden skills.

Although we had no luck with the mammals, the birds were out and about in great numbers. Crimson rosellas chatted to each other in the woodland canopy, while the currawongs and white-winged choughs stayed on the ridges. Small flocks of silvereyes moved through the trees, feeding on the brightly-coloured berries of fragrant saltbush (Rhagodia parabolica). (More about that tomorrow.) They were accompanied by yellow-faced honeyeaters, striated pardalotes and numerous LBJs, all of which were no doubt thrillingly rare and unusual but remain unidentified. A sacred kingfisher kept an eye on us for a while, until a laughing kookaburra took over the surveillance.

More about the northern end of the park soon. In the meantime, here are some of the botanical beauties of the bush …

Fragrant saltbush (Rhagodia parabolica) is widespread in inland South Australia but is very limited in Victoria.

Mistletoe (Amyema pendulum) on yellow gum (Eucalyptus leucoxylon).

Native elderberry (Sambucus gaudichardiana) has edible berries but we left these for the birds.

Mistletoe (Muellerina eucalyptoides) on yellow box (E. melliodora). Its roots insinuate themselves along the branches in a slightly sinister way.

Forest germander (Teucrium corymbosum) occurs in the damper areas along the river bank.

Rock clefts provide protection for smaller plants including this purslane (Calandrinia)

Stonecrop (Crassula) is one of a handful of succulents in Australia.

Necklace fern (Asplenium flabellifolium)