The early blooming of flowers has serious implications for the environment
Last week, the Lost Gardens of Heligan (located in south Cornwall), reported that rhododendrons in their sub-tropical gardens are blooming two months early, and in the depths of Hartland (where the Ecologist is now based) there are now daffodils, snowdrops, violets, primroses and celandines in bloom - with wild garlic and alexanders thrusting their delicious stems and leaves through the wet earth.
On the other side of the Atlantic there is a similar trend for early flowering. In 2010 and 2012, for example, flowering plants in the eastern US produced blooms earlier than at any point in recorded history.
Interestingly, it is thanks to the work of two pioneering US ecologists who have long inspired the Green movement – Aldo Leopold and Henry David Thoreau – that we have any historical data to make these comparisons. Thoreau began observing spring bloom times and temperatures in Massachusetts in 1852 and Leopold started recording the same in Wisconsin in 1935.
Using this information and data about recent seasonal variations, scientists have discovered that plants bloom on average, 4.1 days earlier for every 1 degree Celsius rise in mean spring temperatures.
What is unknown is what this premature blooming has on plant physiology. Certainly a lack of pollinating insects at this time of year affects the setting of seeds, but biologist Elizabeth Ellwood from Boston University suspects that whilst it's remarkable that plants seem to be physiologically 'handling' increasing temperatures, at some point, “something’s gotta give.”
The concern is whether plants will be able to adapt and thrive fast enough to cope with climate change or whether there will be physical limits that they come up against. For example, lack of cold weather can affect germination rates for certain species, whilst other species are colonising and outcompeting native plants as they “march north” from warmer climes.
“Early blooming has tremendous implications for the environment as a whole,” says Ellwood. Millions of plants adversely affected by climate change could eventually affect water and carbon cycles.
Thoreau and Leopold did not collect data on winter temperatures, which would have helped this new study immensely, nonetheless we know that both men were enchanted by the season of Spring. Thoreau wrote in 1852 that Spring “is a natural resurrection, an experience of immortality.”
Lorna Howarth is a writer and environmentalist. She is a contributing editor to Resurgence & Ecologist magazine and the founder of a small independent publishing ageny:
The Write Factor www.thewritefactor.co.uk.
Image of wild primroses courtesy of www.shutterstock.com