A second study has linked logging and bushfire severity, with regrowth burning more fiercely. Image by Sean Davey/AAP PHOTOS

Environment

Study warns logging makes bushfires worse

2020-05-19 15:21:38

Logging has been linked to hotter and more intense bushfires, with older forests faring better in the intense blazes that have ravaged parts of Australia.

A new University of Tasmania paper published in the journal Fire mapped fire intensity in the Huon Valley from early 2019.

There were more severe fires in plantation forests and logging regrowth while blazes in old-growth areas were far less intense.

Fires in mature forests were also less severe than in logged areas.

The study found allowing eucalypt forests to mature further than the normal cycles of 40 to 90 years could help reduce fire hazards. 

Old-growth wet-eucalypt forests, which are the most commonly logged forest in Tasmania, are more resilient to fire than younger growth.

Older forests contain shady, wet layers below the canopy with non-flammable rainforest plants that help slow down fires.

Younger forests have a higher density of eucalypts and drier lower layers, making them more flammable.

One of the paper’s co-authors Jennifer Sanger said regrowth from logging and plantations often formed the divide between untouched forests and communities.

“There have been calls from the forestry industry after the recent bushfires to use logging as a way to reduce the fire risk,” Dr Sanger said.

“This is extremely misleading as our research has shown that logging can make forests more fire prone.”

She said the impact of logging needed to be considered in planning for fire safety.

It’s the second peer-reviewed study to link logging and bushfire severity this month, with a comment piece in journal Nature Ecology and Evolution also making the connection.

Five senior Australian scientists warned logging native forest was likely to have exacerbated Australia’s bushfire crisis, which ravaged large swathes of NSW and Victoria over the summer.

David Lindenmayer, Robert Kooyman, Chris Taylor, Michelle Ward and James Watson wrote logging regimes had made many Australian forests more dangerous, contributing to increased severity and flammability.

“Policymakers must additionally recognise that land management such as logging operations also has profound effects on fire severity, fire frequency and other key aspects of fire regimes,” they wrote.