Wildfires ‘aided’ early flowering plants

LONDON - Scientists have said that the spread of early flowering plants 145-65 million years ago was boosted by wildfires.

Higher temperatures and atmospheric oxygen levels established “angiosperm fire cycles”, which allowed the “small, weedy” plants to regenerate after a fire, giving them an advantage over conifers, they said.

“It was also a time when there was a large number of fires, partly because there were probably higher atmospheric oxygen levels than there are today,” the BBC quoted Andrew Scott at University of London, as saying.

“Angiosperms, particularly weedy angiosperms can also quickly provide fuel ready to be burnt; this means that they have quite a good competitive advantage over other plants,” he said.

He said that many of the early angiosperms were small, herbaceous or shrubby “weedy plants”, so when wildfires - especially surface fires - frequently swept through an area, it created a positive feedback cycle.

“It prevented other plants getting into an area - most of the trees at this time were conifers. If you have relatively regular fires then the trees can never grown above the height of the flames,” Scott said.

This meant that gymnosperm plants were unable to regenerate as quickly as the angiosperms and lost the opportunity to shape the surrounding habitat.

“Over the past 30 years, there have been large numbers of deposits found containing charcoalified flowers, so much of our understanding of the early flowering plants comes from these flowers,” Scott said.

“We now know that fire had a much more important impact in the Earth system than previously thought - not just in the Earth’s atmosphere system, but as we are now suggesting, it also affected biological evolution and diversification.”

The findings have been published on the New Phytologist journal’s website. (ANI)