A forgotten 30-year forest experiment just delivered a huge surprise

A 30-year forestry experiment in Australia found that heavily thinned mountain ash forests grew unusually large trees while recovering enough carbon to match or exceed untouched areas. The results suggest carefully managed thinning could support timber production, wildlife habitat, and carbon storage at the same time. A forgotten 30-year forest experiment just delivered a huge surprise.

Australians have argued about this for decades. The debate is often framed as binary: do we protect forests entirely, or harvest trees to support local economies and communities. The reality is more interesting, as our new research on a long-forgotten experiment in Victoria’s mountain ash forests reveals.

Since the 1970s, scientists and the public have questioned the use of clearfell logging – where all trees in a block of forest are cut down. Conservationists argued it destroys habitat for rare species and reduces the forests’ ecological value. Foresters said mountain ash is adapted to catastrophic bushfires, and clearfelling is the forestry equivalent.