“Without EucFACE, prediction models would rely on data gathered from experiments run in the northern hemisphere, which were based on richer soils…” Since its launch in 2012, the iconic EucFACE experiment, based at WSU’s Hawkesbury campus, has exposed a patch of native forest in north-west Sydney to high levels of carbon-dioxide – replicating our predicted future atmosphere.
Key highlights emerging from the research indicate that:
– Australian eucalypts are limited by soil nutrients, meaning that their ability to absorb and store additional carbon from the air is limited by the lack of nutrients required to produce the extra growth needed to store more carbon. This means that while they absorb some of the extra carbon, it seems to pass through the leaves and roots and back out into the atmosphere without being captured (source).
– Researchers were able to demonstrate that phosphorus was the major limiting factor in Australian soils and that eucalypts respond very positively by adding additional phosphorus, demonstrating the connection between carbon and soil nutrients (source).
– However there is evidence that the trees are better able to access even tiny amounts of soil nutrients under elevated CO2 (source).
– Elevated CO2 reduces the numbers of arthropods (spiders, insects, etc) in the canopy and on the ground compared to untreated areas, indicating that essential communities of pollinators, predators and prey organisms may not respond well to future environments (source).
– The factor that drives the behaviour of the forest is water, alongside elevated CO2. When forests receive good rainfall, the trees burst into growth and the soil microbes are highly active. In dry conditions, parts of the forest becomes relatively dormant. Water availability is the major factor that influences growth (source).
– Trees under elevated CO2 become more efficient with water use, using less water to grow more leaves in good conditions (source).
– Higher levels of CO2 in the air result in more carbon being cycled through trees and through the soil and then back into the atmosphere than under untreated conditions (source).