Scientists dig deep for soil research

New soil research is expected to have a major impact on how future climate change events are forecast.

Landcare Research in New Zealand and the Macauley Institute in Scotland have been able to differentiate and measure respiration rates of carbon dioxide between roots and soil in an undisturbed forest system, using a stable isotope Tuneable Diode Laser Absorption Spectrometer.

The spectrometer belongs to Landcare Research and is the only one in the Southern Hemisphere. It accurately measures the exchange of carbon between vegetation and the atmosphere, using naturally occurring non radioactive isotopes of carbon and oxygen as tracers. Information is provided in unprecedented detail and in real time.

“It’s taken three years planning but now we have shown we can partition how much carbon respiration comes from the roots and how much comes from the soil in an undisturbed system and we’ve never been able to do that before. Furthermore, we don’t think anyone else has ever done it in the world before,” Dr David Whitehead of Landcare Research says.

While scientists can measure carbon released from trees into roots, the other significant component is the mass of old carbon which sits in the soil. As the temperature increases through climate change scientists expect the respiration rate of the soil to increase.

“The huge problem is if that increasing temperature unlocks large storage of historic carbon in soils. If that happens then it adds more carbon dioxide to the atmosphere,” Dr Whitehead explains.

Using the spectrometer scientists will be able to increase the number of samples taken by at least 1,000 times and will also have a greatly improved understanding of ecosystem carbon dynamics.