The changing of the forest colors in the autumn is caused by the retreat of the same pigment as the one that makes the leaves green in the spring – chlorophyll. Chlorophyll absorbs solar rays, which in turn is used for the production of the plant nourishment, namely simple sugars produced by water and carbon dioxide. As daylight hours become shorter at the end of summer and the temperatures drop, the chlorophyll of the leaves begin to degrade and their hidden pigments such as beta-carotene comes to the fore. Here, in the Varanger peninsula in northern Norway, the mountain birch has painted the landscape in beautiful colors of orange, red and yellow.
From album: World Forest Ecosystems