Extreme warming triggered extinctions and surges in plant diversity

Melbourne (ANTARA) — Extreme global warming triggered mass extinctions as well as surges in plant diversity during two periods over the past 140 million years.

The findings offer new insight into how flowering plants became the dominant plant group on Earth, according to a new study.

The study analysed fossilised pollen and spores to show that periods of extreme global warming in the mid-Cretaceous and early Cenozoic played an important role in the evolution of plants, including flowering plants and other major plant groups on Earth.

The University of Tasmania (UTAS) in Australia said this in a statement released on Thursday (15 October).

Researchers said land plants underpin almost all land animals, fungi and bacteria, while flowering plants are the most productive and diverse group, with around 400,000 species worldwide.

According to the study, published in the journal Nature Plants, the team analysed more than 60,000 fossil records and applied a method designed to address a major bias in the fossil record. This enabled them to produce new estimates of fossil pollen and spore diversity over the past 130 million years.

Study co-author Professor Greg Jordan of UTAS said plant extinctions and the emergence of new, evolutionarily related plant groups occurred mainly during the two periods of extreme global warming.

Each period lasted several million years, and the warming both destroyed and drove plant diversity over “millions of years”, Jordan said.

By contrast, cooler periods were marked by little change in plant diversity.

However, the researchers warned that human-caused warming is likely to trigger plant extinctions far more quickly than extreme warming events in the past.