International researchers led by geologists from Utrecht University have discovered that massive wildfires swept across Europe for up to 300,000 years following a global mass extinction event roughly 201 million years ago.
The study, reported by Wionews, found that the long-lasting blazes were sustained by the rapid spread of ferns, which provided continuous fuel across north-west Europe after ancient forests perished.
The environmental catastrophe began at the boundary of the Triassic and Jurassic periods during the breakup of the supercontinent Pangea. Massive volcanic eruptions occurred across the Central Atlantic Magmatic Province, releasing huge amounts of carbon dioxide into the atmosphere.
Scientists estimated that global average temperatures rose by 5 to 10 degrees Celsius as a result of the emissions. The rapid climate shift triggered a mass extinction that destroyed about 76 percent of all terrestrial and marine species.
Sediment core analysis
To investigate the ancient blazes, the research team drilled four boreholes to retrieve deep sediment samples from the earth. One sample was extracted from a depth of almost 640 metres.
Researchers searched the bottom sediment layers for fossil charcoal and organic compounds produced during combustion. By correlating these geological samples with other fire records, the team established a direct connection between darkened fossil layers, intense fire activity, and widespread fern populations.
Utrecht University, a public research university in the Netherlands, led the international investigation. Extracting deep sediment cores enables geologists to study chemical markers preserved in rock layers, providing a record of ancient environmental disasters.
Fern feedback loop
As forests collapsed across north-west Europe, opportunistic ferns rapidly populated the scorched landscape. Lead author Bas van de Schootbrugge noted that ferns not only adapted to the fire-prone environment but also became a major fuel source that drove new fire outbreaks.
Certain fern species can recover quickly after a wildfire because their root systems remain alive underground even when surface foliage burns away. The plants regenerated quickly, dried out, and created dense mats of flammable material that ignited during subsequent dry periods.
This repeating ecological cycle created a feedback loop where fires destroyed vegetation, ferns recolonised the land, and dried ferns sparked the next fire. Researchers estimated that this fire activity continued for between 40,000 and 300,000 years after the mass extinction began.
During the Triassic and Jurassic periods, Pangea contained virtually all of the landmasses on Earth before tectonic movement separated the supercontinent into modern continents.
