As spring goes and autumn comes, nature will add new clothes. The leaves will change from green clothes to yellow gold clothes, and even change into bright red skirts to dance. It turns out that this is related to the function of leaves to produce food - "Photosynthesis". Photosynthesis is that plants absorb sunlight and cleverly transform carbon dioxide in the air and water absorbed from the soil into nutrients. For photosynthesis, leaves make chlorophyll and absorb sunlight. In fact, there are many different pigments in the leaves, including chlorophyll, lutein, carotene, etc. but when the leaves carry out photosynthesis, they will produce a lot of chlorophyll. Because the green is stronger, it is green, so most of the leaves we see are green.
In winter, the temperature drops, and the weather is relatively dry, some areas even freeze, so before entering the winter, the plant will temporarily stop photosynthesis, and absorb the nutrients from the leaves back to the stem for storage. As the leaves stop photosynthesis, they no longer produce chlorophyll, the original chlorophyll, due to low temperature, slowly destroyed and disappeared. Other pigments, such as yellow, which are hidden in the leaves, will appear. Some leaves turn red because they make red anthocyanins in autumn. No matter what color it is, the leaves will wither and fall in autumn because they lose their function of making nutrients.