How Burning Trees Can Improve Biodiversity

By David Warne, Project Leader – Bioenergy, Greening Australia and Doug Phillips, Portland Seedbank Manager, Greening Australia

Greening Australia’s Biochar and Energy from Trees (BETR) project, funded by Alcoa Foundation, is tackling climate change and biodiversity decline in Australia using financial incentives provided by the emerging carbon economy. While it seems illogical that Greening Australia, a non-profit environmental organization, would promote burning native trees, their research team has devised a project in which burning trees actually helps improve biodiversity, connects fragmented landscapes and even provides economic benefits to farmers. Now, what if we told you the project also provides a carbon-negative approach to energy generation – actually drawing carbon down from the atmosphere and sequestering it while producing energy?

So how does this work? Australian farmers face erratic weather patterns and loss of soil cover due to erosion and wind. The growth of farming has led to a decline in biodiversity as a result of the widespread land-use changes. Growing native-species tree plantations which are burned for saleable or locally usable energy can help improve local biodiversity, connect fragmented landscapes and reduce soil loss. The addition of another crop provides economic diversification for farmers and a hedge against agriculturally poor years.

In Greening Australia’s plan, these mixed native species tree plantations are grown specifically for the purpose of burning. Innovative new technology allows wood chips to be burned in a low-oxygen gasifier machine, which produces two outputs from the process: syngas (a combustible fuel) and biochar.

Biochar is essentially charcoal made from organic materials (in this case wood), and can be used for the long-term capture and storage of carbon (biosequestration). Because biochar is a very stable form of carbon, it can be used to draw carbon down from the atmosphere, and can sequester carbon in the soil for hundreds to thousands of years. To sequester the carbon the biochar, which looks like wood chips made of charcoal, is typically tilled into soil and left there indefinitely.

Biochar also has agricultural applications, as it is able to absorb nutrients needed for plant growth and increase water retention, thereby reducing the amount of fertilizer a farmer would need to use; and a lot of work exploring the benefits of biochar is occurring around the world. Preliminary results of Greening Australia’s research suggest that the addition of biochar to soil may also improve the overall health and fertility of a native trees and shrubs.

Greening Australia’s ground-breaking research is bringing together farmer groups, landholders, leaders in the bioenergy industry and academic researchers to undertake a triple-bottom line feasibility study investigating bioenergy generation from purpose-grown mixed native species plantations, and integrating the biochar from this bioenergy process back into farming systems to tighten the carbon/energy loop. So tilling biochar into the soil could help create a virtuous circle by fostering growth of the farm’s agricultural crops as well as its tree plantations. If this works, it will significantly increase native vegetation cover in Australia to provide much needed habitat and landscape benefits, as well as an income streams for landowners that will enhance rather than displace current food and fibre production systems.

Biochar has been an increasingly hot topic over the last few years. Various claims have been made about improvements in the moisture-retention of soils, as well as improved soil health and productivity. While there has been a great deal of research done on the effects of biochar in cropping systems, very little has been done to look at the effects of biochar on native vegetation. During the last year, Greening Australia has designed and set up three replicated field trial sites across South Eastern Australia (Victoria), with two aims:

• To quantify the growth and survival effects of native species after adding varying concentrations of biochar to soil


• To determine if adding a large amount of biochar to soils has a positive, neutral or adverse effect on the growth of native seedlings, as this will provide an indication as to how much carbon could potentially be stored as biochar under revegetation

It has now been nine months after Greening Australia’s biochar field trials were established, and some interesting observations have been recorded, with one site showing visible increases in growth rates of trees where soil has been amended with biochar. Further analysis of the data will determine if these recorded increases are of statistical significance. Stay tuned!

For more information, visit the IIE program website, here.

Please see this link to watch the informational project video.