Leaf by Leaf

Autumn colours draw phenomenal crowds to Japan outdoor areas for the foliage, most prized of all being the maples. It's hard to resist. My wife and I have been grateful for the chance to view the vibrant colours during Kamikōchi trip this autumn. 

Calendar checking is getting more difficult when the climate change has pushed back the peak of autumn leaf season over the past decades. A study in the United States has confirmed delayed arrival of red maple leaf colours by more than a month since the 19th century.

Have you thought about the reason of leaves turning yellow and red? As the award-winning author Tristan Gooley told us, nature is not a whimsical artist splashing variety onto our landscape in the hope of winning prizes for creativity. According to his book How to Read a Tree, there must be a reason for every one of the differences we see. 

Next time you see leaves turning yellow, you know it is a negative effect: you see yellow, but you're actually looking at an absence of green. These are times when trees draw chlorophyll from their leaves back into themselves: the trees dare not waste such as a valuable resource as daylight hours decrease. Much like a photographer putting back camera after dark, the trees have evolved an adaptation strategy to prepare for winter. On the flip side, some trees like oak and maple produce sugars during the day that are then trapped inside by longer, cooler nights. The sugars lead to the production of pigments, such as anthocyanins, which serve as their "sunscreen", so to speak, when their chlorophyll is recycled. The anthocyanins are what make maple trees look red and attractive to us during autumn.