Beautiful autumn colours, why?
Autumn offers a kaleidoscope of colours of plants, nature at is best. Of course, as a scientist, observations need to be explained. What on earth is going on? First of all, plants are the only living organisms which produce their own food. We call this process photosynthesis. ‘Carbon Dioxide and Water (including heat and light energy) produces Oxygen and Glucose’. One product essential for us to survive, oxygen (thanks plants) and glucose (a form of sugar) for themselves. To do this, plants need leaves and the vast majority are green. To make them appear green, according to our visual reception (many insects would not agree with us), a substance called chlorophyll is essential. At this time of the year leaves change their colour. Almost all plants do this to prepare themselves for the winter, i.e. their time of hibernation. Hence, they need to store chemical energy within their system to survive. Chlorophyll is degraded and withdrawn from the leaves (allowing all the other colours to appear) and distributed all over the plant, storing food.
Clever roots
Once all goodies are taken out of the leaves they fall off and most of them into the vicinity of the tree. Reminding us that the volume occupied by the roots is at least twice of the above ground appearance, the soil covering those is a sponge of nutrients. The leaves are composting on the ground and the roots are taking in the minerals and nutrients. The roots have a strong symbiotic relationship with the soil’s fungi thus working as a team to benefit both. Aren’t they clever?
Thank you to one reader to explain light refraction or dispersion as the cause for the red sky in the morning and evening. Related to today’s article, how do the plants know when to start autumn procedures? And what leaves are these? Please email us your answer.
Cheerio,
Christoph