Monday, 19 May 2008

Forty Mile Scrub

Just north of the turn off to Mount Surprise, Georgetown and the Gulf of Carpentaria, is a gravel parking spot large enough to accommodate half a dozen road trains, a sweep of lawn with picnic tables and a track through a dry rainforest.

In all the years of travelling to Undara and the Atherton Tablelands, I’d never visited Forty Mile Scrub. Actually, I'd never been on that part of the Kennedy Developmental Road. From Townsville, I'd driven up to Undara and then pushed on to Chillagoe along a 4WD track that left the Gulf road east of Mount Surprise and joined the Burke road at Almaden. From the Tablelands, I always veered east onto the Palmerston Highway. So that stretch of road between Ravenshoe and the turn off was Terra Incognita.

Dry rainforest — more accurately, semi-evergreen vine thicket (SEVT) — is a type of closed forest that grows in areas subject to markedly seasonal rainfall. At Forty Mile Scrub, almost all of the annual precipitation comes down during the Wet, between December and April. For the rest of the year, there's bugger all. Plants cope with the prolonged Dry by dropping their leaves if necessary. Hence the term 'semi-evergreen'. As for vine thicket — lianas snake between the trees and the canopy is low.

A short walk in the vine thicket

Explaining it all

Kurrajong (Brachychiton australis) emergents tower over the low canopy

SEVT often grows in the same areas as eucalypt woodland. Here's the problem — one of those vegetation types is fire-sensitive, the other is fire-dependent. Because of its susceptibility, SEVT persists only in spots protected from fire, such as rocky gullies and basalt flows. Unfortunately, many of these spots are not protected from cattle and/or weeds, so the vine thickets get bashed around by other foes, some not so easy to control.

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