Meanwhile, the increased sunlight reaching the forest floor allows brush to grow, which is better habitat for species needing early seral conditions. Species composition would change unless more canopy is left. Ideally the forest would be a mosaic of different habitats allowing for great diversity. In actuality, because removal of the largest trees was the type of harvest preferred for so long, there is currently a dearth of late seral habitat in our national forests. This past 'high grading' also left a lot of slash behind, which quickly dried because of the increased sunlight reaching it, thus increasing the amount of fuel for wildfires.
Scientists agree that logging has increased wildfire risk more than any other human activity.
Fire is a natural and important part of the ecology of our western forests. Western forests evolved with regular intervals of low intensity fire, and in many cases species benefit from fire's effects. Scientific consensus is that a five to ten-fold increase in fire is now needed to return our national forests to a healthy fire regime. This should be low intensity fires that leave behind a mosaic of habitats, though, not the huge, catastrophic wildfires we may have unintentionally exacerbated. In many areas, however, because accumulated fuels are so thick, biomass thinning should precede prescribed fire, to lessen the risk of the fire reaching the forest crown and escaping control.