Good morning and welcome to autumn! Or spring for those of you in the Southern hemisphere 🙂
Yesterday was the autumn equinox with the day being equal to the night. From now on, nights start getting longer and days will be getting shorter. It’s not all bad though, autumn brings with it beautiful colours, chilly evenings, pumpkins and Halloween.
As the days get shorter and shorter, trees know to start getting ready for winter when there will not be enough light or water for them to survive.
Photosynthesis is the way that leaves make food and chlorophyll is the chemical necessary for this process and is what gives plants their green colour. As the trees shut down and get ready to rest over winter (they will survive because of food stored during the summer), the green chlorophyll disappears from their leaves.
Yellow and orange colours were there all along, just hidden by the chlorophyll, bright reds and purples are caused by trapped sugars turning red with the sunlight and cool nights and brown is due to wastes left in the leaves.
Along with changing colour, some trees will drop their leaves. They do this by sealing the spots where leaves are attached which means that water can’t flow in and out of them. This is really important as there are tiny holes in leaves resulting in trees losing a lot of water. It’s a bit tricky for trees to replace this water in winter.
They are then ready to dry out, fall off and float down gracefully to make a beautiful, crunchy, colourful carpet ready for many fun hours of play.
What is your favourite thing about autumn?