Jennifer Marohasy

a forum for the discussion of issues concerning the natural environment

Archives for June 30, 2005

How Much More Water?

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It has been very wet in Brisbane over the last couple of days. But not as wet as on the Gold Coast where over 400mm has fallen over the last 24 hours. The Hinze Dam, that supplies the Gold Coast, is predicted to fill completely some time this evening. But there has not been much runoff into the three dams that supply Brisbane the Wivenhoe, Somerset and North Pines dams.

Nevertheless there is a feeling that the recent drought has finally broken.

But, I would argue, now is not the time to stop thinking about new water infrastructure. It is unlikely to keep raining, while the population in the SE of Queensland is predicted to keep growing.

It was only two months ago, on the 27th April that Queensland’s Premier Beattie and Treasurer Mackenroth announced water projects worth more than $2.3 billion including a new dam and possible desalination plant as part of a grand SE Queensland Infrastructure Plan.

After perusing the plan and wondering how much extra water the projects listed in Table 6 of the glossy were likely to deliver, I phoned my local state member Ronan Lee MP and asked him a few questions including how much extra water the projects listed in the Infrastructure Plan (including the dam and desal plant) were likely to deliver.

Ronan Lee couldn’t answer my questions. He said if I sent him an email he would have a go at finding out, or forward the information to the Premier.

I sent an email off on 5th May.

On 30th May I received an email from the Premier’s Chief of Staff letting me know that the issues I raised had been noted and fall within the responsibilities of both the Deputy Premier and the Minister for Natural Resources and Mines and they would all have a go at answering them.

Then just today, 30th June, I received an email from the Treasurer telling me that my email “seeks information on the amount of water that the projects identified in the Infrastructure Plan and Program will deliver”. That was one of my questions.

The email then went on to tell me that this question would be answered by the Minister for Natural Resources and Mines.

You wouldn’t want to be in a hurry!

While I can understand that my local member, the Premier’s Chief of Staff and the Queensland Treasurer, may not know the answer, you would think they could easily find it out/give me the name and number of someone who does?

Indicative information about storage capacity etcetera should have been in the glossy document launched on 27th April.

Fire, Folly & Dead Canaries

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In National Parks, Reserves, and on private property in south-western Australia, grasstrees are under termite attack, rotting, breaking off, and toppling over, due to vast accumulation of thatch. The grasstree in this photograph, with heavy thatch removed by hand to show the decay underneath, is typical of thousands.

View image of grasstree rotting under long fire exclusion in Yalgorup National Park, Western Australia (38kbs).

Had grasstrees been covered by heavy thatch when Europeans first arrived, there would have been no reason to call them ‘blackboys’, since the black stems would have been largely hidden. Only rarely would they have produced a flower stalk, usually weak and twisted, quite unlike a spear. More likely popular names with British settlers would have been ‘greybeards’, or ‘haystack trees’. Early sketches and paintings consistently show them, quite clearly, as recently burnt, with black stems, little thatch, and a prominent flower stalk, like a spear.

As a rule of thumb, a grasstree thatch fire lasts as long in minutes as it has been unburnt in years. A three year old thatch will flare for only a few minutes, doing little damage to the green crown. A thirty year old thatch will burn for half an hour or more, reaching an incandescent thousand degrees Celsius.

Such fierce thatch fires often kill the grasstree immediately, because the protective mantle of old leaf bases is rotted away. Where dead eucalypt leaves, or casuarina needles have formed a ‘birds nest’ in the green top, the rot is exacerbated, the green top is reduced in size and vigour, and the eventual fire may completely burn the green top. If the grasstree survives the immediate fire effect, it is forced to live on starch reserves until a new top can grow. Complete replacement of the top can take a year, and the plant may die in the meantime, if its starch is exhausted.

If grasstrees are burnt more often, when the thatch is small, they flower and seed profusely, the protective mantle remains intact, the green top remains largely unburnt, nutrients in the thatch are recycled, and soil pH around the base is raised. The needles become obviously greener, longer, and thicker. Fire scars on some grasstrees along the old railway track in John Forrest National Park show annual burning by railway gangs when the railway was operating from the 1890s to the early 1960s. These grasstrees obviously survived. Now, under long fire exclusion, they are beginning to die.

There is a serious conservation problem with these old icons of the bush. Although still plentiful, the possibility of mass collapses and local extinctions cannot be ruled out. Grasstrees are like the Miner’s Canary – they are warning us that something is amiss in our bushland. The West Australian Government’s”Threatened Species Unit’ has been informed, but, apart from asking me to fill in a form, I am unaware of any action on their part. Perhaps the concept of ‘common and endangered’is too intellectually audacious for those accustomed to the familiar mantra of ‘rare and endangered’. But would a miner be wise to ignore his canary falling off the perch, because canaries are still plentiful?

By David Ward, Retired Senior Research Scientist with the Department of Conservation & Land Management, Western Australia, and formerly Visiting Senior Research Fellow at Curtin University School of Environmental Biology.

Copyright David Ward, 30th June 2005