Environmental Science · Global and Planetary Change
A lake-sediment record from southeastern Australia shows that colonial land-use change disrupted Indigenous burning practices and transformed open woodland into denser eucalypt forest. The changes occurred before anthropogenic warming and may have increased the landscape’s vulnerability to intense wildfires.
A new mapping method tracked individual fires across the frequently burned savannas of Western Australia’s North Kimberley. The study found that large fires became about half as large during a period of improved fuel management, although the available data cannot establish that management caused the decline.
A study of fossil charcoal from a Palaeocene lake record identifies several phases of wildfire intensification during and after an ancient warming event. Early increases coincided with drying and the spread of flowering plants, but a later rise in fire activity appears to have been linked more to the type of vegetation available than to continued warming.
Amazon droughts were linked to stronger wildfire pollution during the dry season, according to a study covering 2010 to 2015. The researchers estimate that fire-related exposure to fine particles and ozone raised premature mortality more in drought years than in other years.
Prescribed burns made the Brazilian Cerrado shrub Macairea radula flower earlier and for longer, but reduced its fruiting period and fruit abundance. The findings suggest that fire management should consider effects on reproduction beyond flowering.
Measurements in Missoula, Montana, found that aged wildfire smoke contained substantially more fine particles, carbon monoxide and chemical pollutants than a widely used atmospheric model predicted. The researchers estimated that an annually recurring 2020-style fire season would raise excess lifetime cancer risk to about 100 in 1 million, while the model understated that risk by about 40 percent.
