Global warming affects spring wildflower blooms
Data gathered by citizen scientists suggests that bluebells and some other spring wildflowers are slipping out of synch with seasonal temperature cycles. A study published this week in Global Change Biology looked at 22 species of plants; all of them were found to be responding to warming temperatures in spring, by changing when their leaves or flowers emerged.
The data come from hundreds of thousands of observations by amateur enthusiasts submitted to the Woodland Trust’s Nature’s Calendar project. The findings show some are liable to adapt less well than others to rising temperatures, which can impact on their chances to grow and reproduce.
Like in other similar studies, the scientists found that the plants come into leaf or flower an average of three to eight days sooner for each 1 degree Celsius increase in temperature. Some species may lack the immediate flexibility to keep up with changes to their optimum timing, and may need to adapt over several generations in order to cope.
“Plants have an optimum time for developing leaves and flowers – if they get it right, this will maximise their chances for growth and reproduction. As long-term temperatures change, it may alter the optimum timing for plants to develop,” said Christine Tansey, a researcher at the Woodland Trust who led the study at the University of Edinburgh’s School of Biological Sciences.
Seven of the 22 species tracked are likely to keep up with future changes in climate, such as silver birch, beech, ash and wood anemone. Four were identified which may struggle to keep up, including bluebell and garlic mustard. The other 11 species studied did not show a consistent pattern.
The findings are valuable because they show just the importance of data compiled by citizen scientists for helping project climate change impacts.
“The English bluebell is an iconic woodland species so this prediction is a wake-up call for the possible effects of climate change on much loved parts of our natural world,” said Dr. Kate Lewthwaite, Woodland Trust Citizen Science Manager. “It’s important that this data collection continues and now is a great time to start recording this year’s spring activity. It’s really easy – just go to naturescalendar.org.uk to record what you have seen.”