Nature on our doorsteps: Preparing for winter
By Rosaleen Dwyer
Rosaleen Dwyer is the County Heritage Officer at South Dublin County Council – every week she gives us an insight into the natural heritage around us and the beautiful biodiversity of the plants and creatures
Nature’s annual preparation for winter is well and truly underway.
This is most obviously seen in the colourful changes that have occurred with the trees in our streets and parks.
Elegant leafless birch trees in Aylesbury
In the long days of summer, green leaves are busy making food.
They convert water from the soil and carbon dioxide from the air into sugars and starch to help the tree grow and expand.
With the arrival of autumn, the days begin to shorten and light levels drop.
The weather also becomes colder and wetter.
Falling light levels, in particular, make it harder for trees to make food and it is this which prompts them to shut down for winter.
Vibrant autumn colours in Rathfarnham
There are two important reasons why this shutdown happens.
Firstly, trees need to stop wasting further energy trying to make food at a time when light levels are too low for this process.
By dropping the food-making organs (the leaves), trees are conserving vital energy until daylight lengthens again in springtime.
Secondly, trees in full leaf act like a sail in windy weather, greatly increasing the risk of damage to branches and trunks.
Trees without leaves therefore have a better chance of surviving the more frequent storms of winter.
Bare trees also present a nice opportunity for us to appreciate the intricate details of their architectural structure.
By subscribing to The Echo you are supporting your local newspaper Click Here: Echo Online.
TAGS Life
