Besides chlorophyll, there are many other pigments in plant leaves, such as yellow lutein, carotene and red anthocyanin. (Anthocyanin is red in acidic solution), but the leaves are green because of the high chlorophyll content.
In autumn, due to the temperature drop, chlorophyll gradually decomposes, and other pigments are exposed. In addition, the sugar stored in maple leaves will be decomposed into anthocyanins, making the leaves brighter.
Extended data:
China Maple Leaf Capital
20 1 1 In September, Benxi City, Liaoning Province was named "Maple Leaf Capital of China".
Maple is a unique natural resource in Benxi, and colorful maple leaves are a treasure given to Benxi by nature. Compared with other areas, the maple leaves in Benxi have remarkable characteristics.
The types of maple leaves are unique. There are 265,000 mu of maple trees in the city, accounting for 3.2% of the forest land area, and the scale is second to none in the country. The species of maple leaf is a rare seasonal plant landscape in the world.
References:
Baidu encyclopedia-maple leaf