Are the seasons out of sync?

Are the seasons out of sync?
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Daffodils in December. Hawthorn in January. Blossom out in February. It’s clear something’s not right. Year after year, the first hopeful signs of spring seem to be peeping up from the earth earlier and earlier. And what with one of the warmest and wettest winters ever just behind us, it’s been no surprise that this year’s markers of spring appear to have sprung worryingly ahead of time.

There have obviously been the extreme sightings of plants we’d usually see in May appearing in March or before. But it’s more concerning that this had such a widespread impact, it’s now starting to create a trend. While the data isn’t yet available for 2016, The Woodland Trust found that in 2015, which also had a mild winter, trees and plants flowered seven days earlier than average, with the first trees leafing six days earlier and insects sighted 12 days ahead of normal.

Nature’s changing calendar

However lovely it might be for us to see some of the prettiest trees and flowers in their full glory ever earlier, the issue is the effect this could have on their life cycle over the year and their vulnerability to risks like frost, as Guy Barter, Chief Horticultural Advisor at the RHS explains. “Plants are pretty robust and generally unaffected by episodes of unusual temperatures.

"But if a flower comes out in January instead of March, it won’t continue in flower until March but will ‘turn’ well before then, unless indeed it is destroyed by frosts. Early flowering probably means fewer pests and less disease for the plant – which is a good thing – but it could result in less crop in the case of fruit trees, too.”

The problem varies between different species with some more hardy to the ever-changing mercury than others. “Some species are very well-adapted to fluctuating temperatures, such as snowdrops, while others are more delicate” says Dr Kate Lewthwaite from the Woodland Trust. “The longer-term changes to our climate will produce some ‘winners’ who deal with the change and some ‘losers’ who cannot adapt quickly enough.”

What about wildlife?

If these strange seasons continue, causing different plants to do their own thing, there is the danger this could throw the whole ecosystem off kilter. “Because plants and animals exist in a complex network, their differing response to climate changes may lead to mismatches in food webs, throwing nature out of step in the future” says Kate.

“Early plants such as snowdrops and primroses may become out of sync with the animals that pollinate them meaning they have less seed set. Meanwhile, plants that self-pollinate may start to take over” adds Guy.

“Similarly, willows, are important bee forage but if they flower early before the bees are about, there may well be less food for bees when they do appear, meaning colonies of bees will build up slower than usual and there will be less seed set for willows.”

There’s also the problem of the early, milder conditions bringing animals out of hibernation before the plants they feed on are out in bloom. For example, if ladybirds come of out hibernation early, it’s not yet known if the aphids they feed on will be available for them in time.

Give nature a hand

The Woodland Trust is looking for people to be recorders for their Nature’s Calendar project, a huge, useful resource for scientists all over the world to help them understand how nature responds to climate trends. If you think you’d like to help them by noting down the signs of the seasons where you live, please visit www.naturescalendar.org.uk