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.

Descriptions of principal plant phenophases 223 heavy frost, leaf fall may commence abruptly, omitting leaf coloration. Sinel'nikova N. V. and Pakhomov M.N. (2015): The beginning of leaffa ll is to be recorded when leaves fall even in still weather and fresh fallen leaves can be seen underneath tree crowns. Leaf fall would normally begin earlier on a warm and dry autumn, and later on a cold and moist one. Many authors have noted a correlation of leaf fall with temperature indices and, hence, with multi-annual climate fluctuations (Medvedev, 196Д; Schultz, 1970; Terentjeva, 2009). That said, frosts w ill always in tensity leaf fall. 15. PEAK LEAF FALL International phase code BBCH 97 (Growing stage.., 2001; Meier et al., 2009) Phase description The phase is considered to have begun when 50% or more of plant specimens in the transect have shed leaves. The woods look half ‘bare’; this period is quite active, often brief. Some 50% or more of herbaceous plants are already dead to the ground. Further info Sinel'nikova N. V. and Pakhomov M. N. (2015): Peak leaffa ll is recorded on the day when a half of specimens of a species in question are rapidly shedding leaves. 16. END OF LEAF FALL, TOTAL DIE-BACK TO THE GROUND International phase code BBCH 97-98 (Growing stage.., 2001; Meier et al., 2009) Phase description The phase is considered to have begun in trees, shrubs, dwarf shrubs when nearly all plant specimens along the route have already shed leaves. Annual plants die both above and under the ground; in herbaceous perennials underground organs stay alive, whereas aboveground parts either die entirely or some shoots or even leaves survive over the winter.