In a new research, scientists have determined that logging makes forests more flammable, by shifting the composition of moist forests to resemble drier, more fire prone ones.
According to ABC Science, the study, by Australian, Canadian and US researchers, claims that commercial logging of moist native forests creates conditions that increase the severity and frequency of bushfires.
The team focused on how industrial logging practices in native forests might change fire loads, fire frequency and susceptibility to ignition, according to Professor David Lindenmayer of the Fenner School of the Environment and Society at the Australian National University.
"The evidence from rainforests is unequivocal, the evidence from the wet forests in North America is unequivocal and the evidence is starting to build in Australia as well. When you mess with (native wet) forests, they become more flammable," he said.
"The researchers found the removal of trees by logging creates canopy openings and this in turn alters microclimatic conditions, especially increased drying of understory vegetation and the forest floor," Lindenmayer said.
"Work in tropical rainforests suggests that when microclimatic conditions are altered by selective logging, the number of dry days needed to make a forest combustible is reduced," he said.
In one study, uncut native forest would generally not burn after less than 30 rainless days, but selectively logged forest would burn after just six to eight days without rain.
Lindenmayer said that logging also influences the fire regime by changing the density and pattern of trees, altering the spacing between tree crowns and the composition of plants.
According to Lindenmayer, logging in the moist eucalypt forests of East Gippsland in southeastern Australia "has shifted the vegetation composition toward one more characteristic of drier forests that tend to be more fire prone".
He said that clear-felling of moist forests in southern Australia can create more fire fuel because it leads to the development of dense stands of regrowth saplings.
Lindenmayer said that these young forests are more flammable, which often lead to older, less flammable forests abutting them to burn.
Logging slash - the debris left by logging - can also sustain fires for longer than fuels in unlogged forests and can harbour fires when wind conditions are not suitable to spread the blaze, he added.
He said that the industry needs to think strategically about where they log and rethink buffer zones and how big they might need to be.