Evolving relationships between fungi and tree roots intensify rock weathering

Rock weathering by fungi in partnership with tree roots began hundreds of millions of years earlier than first thought, scientists at the University of Sheffield have found. Over time the subsequent evolution of both the root associating fungi and their tree partners accelerated the processes which drive soil development and calcium release from continental rocks to the oceans, where it contributes to the regulation of Earth's carbon dioxide levels over timescales of millions of years. Researchers from the University's Department of Animal and Plant Sciences and Kroto Research Institute discovered that the oldest root-fungus partnership found in the first trees 350 million years ago accelerates mineral alteration, suggesting that its effects on the Earth's surface originated hundreds of millions of years earlier than previously recognised. Joe Quirk from the University of Sheffield's Department of Animal and Plant Sciences said: "Evolutionary advances in trees and their fungal partners accelerated and intensified the biological weathering processes driving soil development and calcium export from land into the oceans, enabling chalk and limestone formation that regulates Earth's long-term atmospheric carbon dioxide and climate history. "This ancient root-fungus partnership, dating back to the origins of land plants, can no longer be dismissed as inconsequential to the processes involved in the breakdown and weathering of rocks that ultimately leads to soil formation and the long-term regulation of Earth's climate system.