Макарова, О. А. Фенологический атлас растений / Н. В. Поликарпова, О. А. Макарова ; М-во природ. ресурсов и экологии Рос. Федерации, Федер. гос. бюджет. учреждение «Гос. природ. заповедник «Пасвик» ; [худож.: Хохлов В. А. ; пер.: Кислова О. С.]. - Рязань : Голос губернии, 2016.

Nature's calendars 197 Yellow flag on downy birch Yellow flag on goat willow The weather is an important factor influencing the course of leaf colora tion and leaf fall. On a warm and dry autumn foliage would begin to change color earlier, and even the hues would be different (“golden autumn”). On a wet and sunless autumn leaf coloration would be delayed and less colorful. If however air temperature rises significantly in the second half of September - first half of October, many trees and shrubs would still change foliage color quickly and sometimes fully. Frost spells or strong wind can cause many plants to drop leaves very intensively. Full leaf (needle) coloration is the day when the entire foliage has Frost is very often in the end of leaffa ll of the goat willow