Thoussands of trees are dying in the forests of south-west Australia, due to insect attack and other causes. I grew up in the south-west of Australia, so the recent story on ABC’s Catalyst science program about large-scale tree deaths in the Marri (Red Gum), Jarrah and Tuart forests of the south-west was more than just interesting, it was distressing. According to Prof Giles Hardy of Murdoch University:
Last summer was the hottest, driest period on record, and we had some hundred and twenty-two days with no rain, we had weeks with over forty-two degrees, and we started to see large areas just collapsing and dying. So we took an aeroplane up and it was amazing to see the extent of the yellowing and purpling and the numbers of trees that were dead. In the Perth hills, we lost approximately twenty-thousand hectares of trees.
The increased warming and greatly reduced rainfall in the south-west in recent decades is not just due to global climate change — up to 50 percent of it can be attributed to local factors such as the destruction of much of the forest cover in the south-west due to human activity over the past hundred years. See A J Pitman et al Impact of land cover change on the climate of southwest Western Australia.
In the Catalyst report, the concluding words of forest ecologist Dr Craig Allen, were ominous:
What’s most alarming is that these die-off events may be just the tip of the iceberg. We know that warming, temperatures exacerbate tree mortality, and the climate predictions are that the world is going to get much warmer soon. Um, so we may be just at the very front edge of what could be wholesale mortality of the world’s forests – the forests that we know and care about today.
For the full video and transcript, visit http://www.abc.net.au/catalyst/stories/3488105.htm
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