In brief : Root cause

 作者:古酣稻     |      日期:2019-02-26 08:02:00
THE rapid evolution of root systems by land plants may explain a 45 per cent drop in atmospheric carbon dioxide levels 390 million years ago. The earliest land plants, about 410 million years ago, had roots that reached only millimetres into the soil. But fossils from Quebec now show that just 20 million years later, some plants had roots up to a centimetre thick and half a metre deep. In Geology (vol 26, p 143), Jennifer Elick of the University of Tennessee at Knoxville and her colleagues say that carbonic acid released by roots would react with minerals,