ALMOST three quarters of damaged forest needs to be protected from logging after major natural disasters, such as fires, in order to preserve its biodiversity, according to a new study. 

Co-author of the study, Prof David Lindenmayer of ANU, says “naturally disturbed” forests are among the most threatened habitats in the world.

“Our study looked at how plants, birds and fungi cope in these forests after events like wildfires, storms and insect outbreaks,” Prof Lindenmayer says.

“In most cases, these forests are subjected to what’s known as salvage logging after a natural disaster, which has long been thought to help recovery. This can have a huge impact on biodiversity.”

The study found about 75 per cent of an impacted area need to be left unlogged to maintain the majority (90 per cent) of its richness of unique species. In contrast, leaving 50 per cent of the forest unlogged only protects 73 per cent of the area’s unique species richness.

“The increasing frequency of natural disasters like the summer 2019-20 bushfires here in Australia has really forced a rethink of this issue,” Prof Lindenmayer says.

“Until now, benchmarks for salvage logging have been unclear, and often differ between countries. These results give us a clearer idea of the best approach going forward.”

The study also shows that these benchmarks didn’t change over time.

“The importance of these unlogged areas didn’t increase or decrease within the first 20 years after salvage logging,” Prof Lindenmayer says.

“In some cases, forests might need several centuries to regrow crucial elements like trees with hollows.”

The study was led by researchers from the University of Wurzburg in Germany. It has been published in “Nature Communications”.