Plants flowering a month earlier due to climate change and that could spell ecological disaster, warn University of Cambridge researchers
Spring in the UK could eventually start in February, University of Cambridge researchers say, after discovering that plants are flowering a month earlier on average in the UK due to climate change.
This could have serious consequences for wildlife, agriculture and gardeners, they warn.
They analysed more than 400,000 observations nationwide dating back to the mid-18th century of 406 plant species from Nature’s Calendar, maintained by the Woodland Trust.
Examining the first flowering dates alongside temperature measurements, they found the average first flowering date from 1987 to 2019 is a full month earlier than the average from 1753 to 1986 - a change that coincides with accelerating global warming from human activities.
“The results are truly alarming, because of the ecological risks associated with earlier flowering times,” said Professor Ulf Büntgen from Cambridge’s Department of Geography, the study’s lead author. “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 synchronised 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 sync, which can lead species to collapse if they can’t adapt quickly enough.”
Nature’s Calendar - which the Woodland Trust first collated in 2000 with the Centre for Ecology & Hydrology - brings together 3.5 million observations of seasonal change recorded by scientists, naturalists, amateur and professional gardeners since 1736.
“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,” said Prof Büntgen. “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.
“Anyone in the UK can submit a record to Nature’s Calendar, by logging their observations of plants and wildlife. It’s an incredibly rich and varied data source, and alongside temperature records, we can use it to quantify how climate change is affecting the functioning of various ecosystem components across the UK.”
The researchers looked at the first flowering date of trees, shrubs, herbs and climbers,
from the Channel Islands to Shetland and from Northern Ireland to Suffolk. They classified the observations by location, elevation and whether they were from urban or rural areas, then compared them with monthly climate records.
If global temperatures continue to increase at their current rate, the UK could witness spring in February, the researchers say, which could lead to serious problems for many of the species on which forests, gardens and farms rely.
“Continued monitoring is necessary to ensure that we better understand the consequences of a changing climate,” said co-author Prof Tim Sparks from Cambridge’s Department of Zoology. “Contributing records to Nature’s Calendar is an activity that everyone can engage in.”
The research, published in Proceedings of the Royal Society B, was supported in part by the European Research Council, the Fritz and Elisabeth Schweingruber Foundation and the Woodland Trust.
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