Wednesday, July 25, 2007

Acacia georgina

(Simul-blogged with Molecule of the Day.)

Much of our exploration area is loacated in gidgee country. Gidgee is a slow growing acacia tree that forms scrub, savanna, or low woodland in the claypans, stream beds, and dolomite areas of the basin.

From the bushcraft point of view, gidgee is the perfect firewood. It burns easily, hot, and long, with few sparks or pops. It was not unusual for us to put a log on at dinner and use the coals to heat the billy for coffee water the next morning. Cattlemen, however, are less fond of the tree.

At certain times of the year, or in periods of stress, Acacia georgina can contain high levels of fluoroacetic acid, the sodium salt of which is the poison 1080. Molecule of the Day gives more information on the chemistry and toxicity of this substance here, but the effect in the field is that cattle with gidgee poisoning are very prone to stress, and can drop dead when startled or disturbed. Annual cattle losses in the NT from gidgee are on the order of a couple million a year, and there are stories of helicopter-based geophysical surveys wiping out small herds just by overflying them. This is one reason that cattlemen don’t like helicopter work.

The other reason that cattlemen don’t like helicopter work is that healthy normal cows in eventually get used to overflights after a little while. This is great for the cows, but it is not ideal for the station manager when he plonks down several thousand bucks to rent a chopper for muster. The acclimated cows won’t run from a mustering chopper. They’ll just look at it, look at each other, and go back to eating the grass around the gidgee trees.

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