Overview
- The peer-reviewed study was published online July 21, 2026 and uses four sediment drill cores from Germany, Luxembourg, Denmark and the UK to reconstruct vegetation and fire during the end‑Triassic extinction.
- Massive volcanic eruptions about 201 million years ago raised CO2 and temperatures, which the authors say led to forest collapse and a rapid expansion of fern-dominated, savannah-like landscapes across northwest Europe.
- Multiple wildfire indicators—fossil charcoal, PAHs (smoke-produced hydrocarbons), and a newly applied Palynomorph Darkness Index based on the color of pollen and spores—align in the cores to define a synchronous “Dark Zone” that matches the fern spike interval.
- The team interprets the pattern as a fern–fire feedback in which fast-regrowing ferns supplied abundant, highly flammable fuel so that repeated intense fires persisted for an estimated 40,000 to 300,000 years.
- Authors note limits to traditional proxies—charcoal can fragment and PAHs can be transported—so the palynomorph darkness method is presented as a low-cost, complementary way to detect charring in microfossils and to study long-lived climate–vegetation–fire feedbacks relevant to understanding coupled Earth system responses today.