Scientists may have greatly underestimated the impact of future global warming on plants, new research has suggested.
Changes brought about by rising temperatures could be up to eight times more pronounced than experts have assumed, it is claimed.
The forecasts of earlier flowering and leafing are based on outdoor experiments in which plants are artificially warmed. But comparisons between these predictions and historical records of what has actually occurred in nature over the past 30 years reveal major discrepancies.
Scientists conducting the new research, published in the journal Nature, examined data from 50 different experimental studies covering 1,643 plant species on four continents.
Taken together, the studies predicted that every degree Celsius rise in temperature would advance plants' flowering and leafing from between half a day to 1.6 days. However, records of nature-watching observations showed phenological events advancing, on average, five to six days per degree Celsius rise.