 The amino acids released from degradation of light harvesting complexes are stored all winter in the tree's roots, branches, stems, and trunk until the next spring, when they are recycled to releaf the tree.Carotenoids are present in leaves the throughout the year, but their orange-yellow colors are usually masked by green chlorophyll.As autumn approaches, certain influences both inside and outside the plant cause the chlorophylls to be replaced at a slower rate than they are being used up.