Fungi behind extinction of forests 250mn-yrs-ago
The so-called Permian extinction likely was triggered by immense volcanic eruptions in what is now Siberia.
Washington: A new study has revealed that the mass extinction of the world’s forests some 250 million years ago was likely accelerated by an aggressive tree-killing fungi triggered by global climate change.
The researchers suggest the possibility that today’s changing climate could cause a similar increase in pathogenic soil bacteria that could devastate forests already stressed by a warming climate and pollution.
The so-called Permian extinction likely was triggered by immense volcanic eruptions in what is now Siberia. The huge amounts of gas and dust thrown into the atmosphere altered global climate, and some 95 percent of marine organisms and 70 percent of land organisms eventually went extinct.
The scientists claim that thread-like or filamentous microfossils commonly preserved in Permian rock are relatives of a group of fungi, Rhizoctonia, which today is known for members that attack and kill plants.
“Modern Rhizoctonia include some of the most ubiquitous plant pathogens, causing root, stem and foliar diseases in a wide variety of plants,” said coauthor Cindy Looy, University of California, Berkeley, assistant professor of integrative biology.
“Based on patterns of present-day forest decline, it is likely that fungal disease has been an essential accessory in woodland destabilization, accelerating widespread tree mortality during the end-Permian crisis,” she said.
The study will be published in the September 2011 print edition of the journal Geology of the Geological Society of America.