As climate change intensifies, we expect to get a lot more extreme weather events. It’d be great if we could predict how ecosystems will change after those events, but we can’t, for lots of reasons. One obvious reason is – we didn’t collect much information after past events to help guide us in the future.
Way back in ’73, the small town of Raywood, near Bendigo in central Victoria, got 928 mm of rain. On average, Raywood gets just over 400 mm a year, so it was a long wet year. Torrential rains came again in ’74. That Big Wet wasn’t unique to Raywood, and La Nina drenched every town, small and big, across south-east Australia. What impact did that extraordinary event have on native vegetation?
We know the floods of 1973-74 triggered regeneration by river red gums (Eucalyptus camaldulensis) and black box (E. largiflorens) around many rivers and wetlands. But what happened away from the rivers, out on the plains and up in the hills? Did the Big Wet trigger lots of regeneration in other areas as well?
From most regions we have no information at all. Perhaps lots of new plants came up, perhaps none did. We don’t know. That’s a big knowledge gap for such an extreme event. And that knowledge gap is one reason why it’s so hard to predict how ecosystems will change in the future.
Let’s jump forward a generation now, from 1973 to 2010, when La Nina again hit with a vengeance. The spring of 2010 was the wettest on record across Australia. Once again Raywood got a soaking, receiving 904 mm in the year, almost as much as in ’73. A few months later, the summer of 2011 brought even more flooding rains.
What impact did the big wet of 2010-2011 have on native vegetation? Did heavy rains promote lots of regeneration in some areas, but not others? Did some species respond well, but others little? Did lots of new seedlings emerge, only to die later on? Or did nothing much happen at all?
As far as I know, we have no answers to these questions. We don’t have a broad-scale, rapid-response ecosystem monitoring scheme. We probably never will. But this time, it’s not too late to share our observations. Lots of people know what happened in their local area. And we’ve got something big that no one had back in ’73. Social media. Yep, we’ve got blogs on our side.
All of which makes me wonder: this time around, can we leave a better legacy of records than than we did in the 1970s? Can we collate observations from lots of people, across lots of regions, to better understand how extreme weather events affect ecosystems?
Can we crowd source about a cloud burst?
In the next few weeks, this post will (I hope) be read by 400-500 readers across Australia and overseas. If every fifth reader posts a short note in the comments box below, we’d instantly have an amazing collection of observations. And, if many of you pass on this quest through Facebook, Twitter and email, we can crowd source a flood of new stories.
You’ve read dozens of blogs in which I’ve written all the words. Now it’s your turn. Please consider jotting down a short note below, and help us all to learn more than we did in ’73.
What happened where you live, work and play? Did the big wet of 2010-2011 trigger lots of regeneration by trees, shrubs and other plants, or nothing much at all? Which species responded best? If there was lots of regeneration, how have the plants fared since? Are most of them still alive?
To encourage lot of comments, I’ve got two books to give to the two people who send in, or encourage many others to send in, the best responses: Ten Commitments: Reshaping the Lucky Country’s Environment (edited by David Lindenmayer and colleagues) and As If For a Thousand Years: A History of Victoria’s Land Conservation and Environment Conservation Councils, by Danielle Clode.
Bribes Incentives aside, the beauty of social media lies not in a few detailed responses, but in receiving lots of short notes from lots of readers, from the mallee to the alps and the coast. Your observations will be wonderful for everyone to read. No note is too small. If nothing much regenerated, that’s really important to know too. So please leave a comment: What did you get from the Big Wet?
The great comments below have been synthesized in the following posts:
- Wonders of the Big Wet
- The Big Grass years
- The Big Wet regeneration pulse
- Drought, dieback and insect attack