Cool Kids For A Cool Climate

Signs of Spring (Phenology)

Phenology is the observation and recording of natural events, such as the first leaf on a tree, the first frog spawn laid or the first swallow seen. Phenology can be used as a measurement of the impact of climate change.

With rising temperatures spring comes earlier. Some species are very sensitive to temperature changes, but others are less so. If a tree comes into leaf a week earlier, that tree may have longer to photosynthesise and store food, but will the plants living under the tree canopy have time to flower and set seed before their light is cut out by the shade of the tree?

Species that are sensitive to temperatures will find that they have to move 150 kilometres north (in the northern hemisphere) for each 1°C increase in temperature. Alternatively to get cooler animals can increase their altitude i.e. go up mountains. There is obviously a limit to this (i.e. the height of the mountain) Many may find they have nowhere to go, like the capercaille in Scotland. Even the polar bear is in danger.

Of course plants find it a lot more difficult to move – it MAY be OK for animals with legs and/or wings, but most plants are rooted to the spot and will not evolve quickly enough to keep up with climate change. Those with wind blown seeds may adapt easier than those that reproduce vegetatively (such as strawberries which produce runners).

In an ecosystem, all species are interdependent, and the effects of one change can have unpredictable results on other species.
For example it is said that blue tits are not reacting to the rising temperatures in the same way as other species. Insects are emerging and breeding earlier than before. Therefore the blue tits’ eggs are hatching after the main glut of caterpillars is over. There is less food for the parents to feed their chicks with.

Many insects may benefit from the warmer weather including malaria bearing mosquitoes which could come to Europe. However, many of Britain's rarer butterflies are finding it difficult to migrate north. There may not be suitable habitat, or there may not be the caterpillars' food plant available for the adults to lay their eggs on.

Species that migrate also find it more difficult to adapt than do resident birds, they react to the climate in the country they are coming from, not the one they are going to.

Birds like swallows which fly long distances, rely on places to feed on their way. If global warming increases the area of desert on their migration routes, there is less chance for them to feed and many may die before they reach the UK. To find out more about swallows check out the British Trust for Ornithology's Swallow Appeal pages.

To learn more about Phenology and to help record observations visit www.phenology.org.uk

Proof that climate change is causing spring to come earlier comes in a European wide study into phenology

Help Out:

The BBC and the Woodland Trust are running a joint 'Springwatch' survey. Members of the public are asked to record when they first see: a bummblebee; a Peacock butterfly; frog spawn; flowering hawthorn, a 7-spot ladybird and a swift. You are asked to send in your records through the website. The results of the survey will be shown in a BBC2 programme later in the year.
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