A few years ago I was sitting in the living room of my good friends Noel Preece and Penny van Oosterzee in Darwin chatting about life, the universe, and everything. They rather casually mentioned that they would be selling their environmental consulting company and their house and moving to the Queensland rain forest. Ok – sounded like a pretty hippy thing to do when you’re thinking about ‘retiring’ (only from the normal grindstone, at least). But it wasn’t about the easy life away from it all (ok, partially, perhaps) – they wanted to do something with their reasonably large (181 ha), partially deforested (51-ha paddock) property investment. By ‘something’, I mean science.
So they asked me – how would we go about getting money to investigate the best way to reforest a tropical rain forest? I had no idea. As it turns out, no one really knows how to restore rain forests properly. Sure, planting trees happens a lot, but the random, willy-nilly, unquantified ways in which it is done means that no one can tell you what the biggest biodiversity bang for your buck is, or even if it can compete on the carbon sequestration front.
Why carbon sequestration? Well, in case you’ve had your head up your bum for the last decade, one of the major carbon mitigating schemes going is the offset idea – for every tonne of carbon you emit as a consumer, you (or more commonly, someone else you pay) plant a certain number of trees (because trees need carbon to grow and so suck it out of the atmosphere). Nice idea, but if you deforest native ecosystems just to bash up quick-growing monoculture plantations of (usually) exotic species with little benefit to native biota, biodiversity continues to spiral down the extinction vortex. So, there has to be a happy medium, and there has to be a way to measure it.
So I said to Penny and Noel “Why don’t we bash together a proposal and get some experts in the field involved and submit it to the Australian Research Council (ARC) for funding?” They thought that was a smashing idea, and so we did.
Fast forward a few years and … success! The Thiaki Project was born (‘Thiaki’ is the name of the Creek flowing through the property north of Atherton – seems to be of Greek origin). We were extremely lucky to find a new recruit to the University of Queensland, Dr. Margie Mayfield (who worked previously with Paul Ehrlich), who was not only an expert in the area of tropical reforestation for biodiversity, she also had the time and energy to lead the project. We garnered several other academic and industry partners and came up with a pretty sexy experiment that is just now getting underway thanks to good old Mr. ARC.
The project is fairly ambitious, even though the experiments per se are fairly straight forward. We’re using a randomised block design where we are testing 3 tree diversity treatments (monoculture, 1 species each from 6 families, and 5 species each from those same 6 families) and two planting densities (high and low). The major objective is to see what combination of planting density and native tree species provides the most habitat for the most species. We’re starting small, looking mainly at various insects as they start to use the newly planted blocks, but might expand the assessments (before planting and after) to reptiles, amphibians and possibly birds later on.
But we’re not stopping there – we were fortunate enough to get get a clever soil scientist, Dr. David Chittleborough of the University of Adelaide, involved so we could map the change in soil carbon during the experiment. Our major challenge is to find the right combination of tree species and planting techniques that restore native biodiversity the most effectively, all the while maximising carbon sequestration from the growing forest. And of course, we’re trying to do this as most cost-effectively as we can – measuring the relative costs will give landowners contemplating reforestation the scale of expenditures expected.
I’m pretty proud of what Margie, Noel, Penny and the rest of the team have accomplished so far, and what’s planned. Certainly the really exciting results are years away yet, but stay tuned – Thiaki could become the model for tropical reforestation worldwide. Follow the Thiaki Project website for regular updates.
I’d also love to recreate the Thiaki Project in southern Australia because as it turns out, no one knows how to maximise biodiversity and carbon sequestration for the lowest cost in temperate reforestation projects either. All we need is a few hundred hectares of deforested land (shouldn’t be hard to find), about $1 million to start, and a bit of time. Any takers?