Why are some trees losing their leaves already in the UK?

In order to find out why they are falling early, we need to find out what the role of leaves are.

Leaves on a tree are vital for the tree as they gather vital nutrients for the tree from carbon dioxide and the rain water. Most leaves are generally green as this pigment is the most efficient at absorbing sunlight and converting it into energy for the tree.

Normally as the autumn and shorter and colder days of autumn approach, the tree stops gathering nutrients and energy, instead it starts a storage and survival mode, which will last until the warmer and longer days of Spring the following year.

There are other factors that could change the habits of the trees. These factors could be soil health, damage, disease or even environmental changes.

The experts believe the current reason for some trees starting to activate their survival mode early and drop their leaves is probably due to the several heat waves we have had. Especially as they have been back to back, which does not really give the trees a chance to recover and restock up on their nutrients and energy they need to stay healthy.

So despite it feeling that way, Autumn has not come early this year.

As trees are dropping their leaves early, another thing to watch out for are the possibility of dead and dying branches falling from trees. This will also be due to the tree’s survival mode which will stop nutrients going to weaker dying branches. For the tree, losing these branches gives the tree a better chance of survival.

This doesn’t sound too bad as most of the trees will survive by taking this action to protect themselves. However there will probably be a knock on effect that will impact other plants and even animals.

Plants that normally live in the shadows of the trees will suddenly find themselves in full sunlight earlier into the season, flowering too early.

Crops, fruits and vegetables could ripen earlier due to the heat waves too. Or being lost to drought conditions. Some plants are flowering early due to the hot conditions too. Bees are also showing signs of shutting down for the winter, after flowering plants finished producing pollen and nectar in the hot weather. That could leave bees without enough food.

This could have an effect on animals and insects that rely on the Autumn leaves, crops, fruits and vegetation to fatten up before the harsher winter.

Then the impact on animals and birds that feed on the insects.

Experts know it will take time to assess the impacts of the heat waves, but they are also looking at what plant, insect and animal species are doing to evolve through what seems to be this new seasonal cycle.