Bushfire science These diagrams below first presented in 1995 reveal the process of landscape conversion of native forest from moist old growth fire resistant type, derived from their closed canopy, to dry sclerophyl bushfire prone regrowth type. As long as a moisture rich closed canopy is in place a high density of ground cover remains of moderate risk and tends to break down quite quickly as well. The most severe process of logging disruption of the closed forest canopy has been going on since the advent of high intensity 'integrated logging' for timber but also high proportion of woodchips especially since the mid 1970ies. This was around the time of the advent of bulldozers, other big machines and modern chainsaws. Thus even if a small proportion of a forest of say 2 or 3% suffers high intensity logging per year, after 40 years of patchworking, close to 100% of the moist micro climate will have been destroyed along with the broken canopy. It will take maybe a century to re establish the moist old growth closed canopy microclimate across broad areas of forest IF devastating fires don't constantly set the clock back to zero again in a cruel ecological game of snakes and ladders. That's how grim the situation has become in large areas of forested south east Australia as a result of rampaging logging and greed. Even much contemporary national park has been patchwork logged already prior to reservation in the last 40 years and still to regain closed canopy moisture. Depending on the fire patterns in the future they may never regain that closed canopy and moisture level. There are many other factors contributing to bushfire such as ignition sources like arson or naturally occuring dry lightning. Climate impact of low rainfall also impacts fire intensity and risk. Ground fuel levels are also very significant.   
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