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.

208 A phenological atlas of plants DESCRIPTIONS OF PRINCIPAL PLANT PHENOPHASES 1. GROWTH ONSET, BEGINNING OF BUD BREAK International phenophase code BBCH 10 (Growing stage.., 2001; Meier et al., 2009) Phase description Shoot growth begins in herbaceous plants; first breaking buds (begin ning to open) are seen on trees, shrubs and dwarf shrubs. Normally, the end of a phenophase implies the beginning of the next one. The ‘growth onset’ phase is however an exception. In some species, growth begins before young leaves or needles appear. In others, shoots grow simultaneously with the emergence of young leaves, whereas in a third category shoots begin to grow only after leafing of short shoots is almost complete. In rosette plants the growth phase is missing, in grasses it appears as booting. Onset of needle growth in spruce: young needles are light green, quite distinct from dark green older needles. Further info Bulygin N. E. (1991): In most woody plant species the process of leaf unfolding and enlargement is simultaneous with shoot elongation. In the Pine genus, young needles begin to expand before the cessation of shoot growth. Fenolog .rgo.ru: Bud 'bursting' or 'pipping' is the emergence of 'burst' buds exposing green leaf tissue between bud scales at the tips, but the leaves are still tightly rolled and packed together. TerentjevaE. Yu. (2008): Bud sw e lling - buds are enlarged, showing pal er gaps between scales. Bud 'p ipp ing '-a green cone of leaves is visible. Sinel'nikova N. V. and Pakhomov M. N. (2015): Resumption of growth in perennial herbs begins with sprouting. It is recorded when the first shoot bud appears above the ground. Bud swelling in trees and shrubs is recorded when the outer scales of swollen buds begin to separate ex posing paler interior scale tissue. The second sub-phase of bud swelling,