Warmer winters could be confusing crops, prompting a warning from scientists that the agriculture industry could be forced to undergo sweeping changes.
A detailed study of plant species shows that many are responding to warmer winters and getting “messed up” in the process.
For years, scientists have accepted certain species are flowering earlier each year due to changes in climatic conditions, but many – varying around 30 per cent depending on the region – appeared not to be affected and were classed as stable.
However, a group of researchers are now questioning this theory, saying the apparently stable species are, in fact, unquestionably feeling the effects of rising temperatures throughout the year. They say further research is needed to find out what it means, not only for wild plants, but for the future of farming.
Nobel Prize winning scientist Professor Camille Parmesan, NMA Chair in Public Understanding of Oceans and Human Health within Plymouth University’s Marine Institute, was part of the research team.
She said: “For years, horticultural and farming experts have believed they can either use traditional adaptation methods or genetic manipulation to negate the effects of climate change.
“But our studies show the species they rely on – such as many fruit and nut trees – could in fact be getting really messed up by rising temperatures. Farmers may have had several bad years with their crops, but blamed it on other factors, and we feel more research is needed to examine where and when species that need cold winters should be planted to ensure the industry remains active.”
Many of the species that have not appeared to be altering their spring timing in recent years need cold winters to tell them when to become dormant and when to “wake up” in spring. But with winters getting warmer, these species appear to be waiting for their cold cue, which can end up delaying their normal responses to the arrival of spring.
The end result is species that show no change, or even a delay, in spring budding, leafing or blooming, in apparent contradiction with warming spring temperatures.
This new study resolves that contradiction for many species, indicating about two-thirds of ‘stable’ species are, in fact, sensitive to warmer springs, but even more so to warmer winters, with the end result being a confusion in timing of leafing, budding or blooming.
Professor Parmesan said: “I am looking to open dialogue with agricultural research groups and policy makers because while crops that require cold winters may appear to be flowering at their normal time, they may actually be losing out by not starting growth earlier in spring in concert with warmer spring temperatures.”