You may be having a saunter on a crisp autumn afternoon and notice several leaves on the ground, of a variety of colours ranging from brown to red. This is due to the pigment in the leaves changing from the environment around it. Chlorophyll causes leaves to turn green, along with anthocyanins and carotenes creating the red/pink and yellow colours. The colour depends on the elements and the chemical balance. For instance, if it is a particularly cold night, chlorophyll is affected. This means the green colouring fades to a yellow. However if it is warmer temperature, the colour may take on a red hue, due to the sugar concentration in the foliage affecting the anthocyanin. Sunny weather will also enhance this change.

You may wonder why leaves fall off trees during this time. Trees have a hormone called auxin, which helps to keep the leaf attached, due to the layer of cells forming between the stem and the stalk. However, the cooler the weather, the lower the levels of auxin. This is when the leaf would break away and land on the ground below. Leaves breaking away is actually beneficial to the tree, as it helps the tree to withold moisture, instead of getting too dry. Trees without foliage become dormant, therefore the lifespan improves, due to the need for energy decreasing. No leaves means it can also survive in a storm for longer and is less likely to get damaged. Call Arb advice for all Tree work on the Isle of Wight.