The climate crisis in the United Kingdom is shifting the flowering time for plants. Using data extending for hundreds of years, researchers at the University of Cambridge have established that over the last three decades, the average first flowering date is a full month earlier than in the past.
The results, published in Proceedings of the Royal Society B, used data collected by Nature’s Calendar, a citizen science database maintained by the Woodland Trust that goes back to the mid-1700. The scientists analyzed more than 400,000 observations of 406 plant species. The dates of these observations stretched between 1753 and 2019.
To better balance the number of observations, the scientists divided the observations into two sets. From 1753 to 1986 and from 1987 onwards. In recent years, the average first flowering advanced by a full month and is strongly correlated with rising global temperatures.
"We can use a wide range of environmental datasets to see how climate change is affecting different species, but most records we have only consider one or a handful of species in a relatively small area," lead author Professor Ulf Büntgen, from the University of Cambridge, said in a statement. "To really understand what climate change is doing to our world, we need much larger datasets that look at whole ecosystems over a long period of time."
The change of the first flowering date is concerning. At this rate, it is possible that spring might begin in February in the UK, something that could severely harm many species that can’t keep up with rapid changes to seasons.
"The results are truly alarming, because of the ecological risks associated with earlier flowering times," added Büntgen. "When plants flower too early, a late frost can kill them—a phenomenon that most gardeners will have experienced at some point. But the even bigger risk is ecological mismatch. Plants, insects, birds and other wildlife have co-evolved to a point that they're synchronized in their development stages. A certain plant flowers, it attracts a particular type of insect, which attracts a particular type of bird, and so on. But if one component responds faster than the others, there's a risk that they'll be out of synch, which can lead species to collapse if they can't adapt quickly enough."
The team stresses the importance of continuous monitoring and the importance of the contributions by scientists, naturalists, amateur and professional gardeners, Nature's Calendar, which currently has around 3.5 million records.