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.

206 A phenological atlas of plants observations of abundant species or a large group. Where the sample is small, i.e. just several specimens in a transect, the date to be recorded is when at least 10% of leaves or flowers have entered the same devel opment phase. The authors of a widely known atlas and identification guide to phe nophases I. N. Elagin and A. I. Lobanov (1979) proclaim that where signs of a phase are found in the first buds, leaves, flower buds, etc. in at least several plant specimens within a population, the plants should be deemed to have entered the phenophase. Analysis of a great many sources leads to a conclusion posted by В. V. Skrotskij (http://ib.kom isc.rU /add/o ld/t/ru/ir/vt/99-21/06.h tm l 12.06.2016) that, in reality, there is no common technique for pheno logical monitoring in Russia, and comparative analysis is therefore im possible. Referring to G. N. Zaitsev (1978), he stressed that phenological observations are not uniform in content and form, which is a barrier to use phenodata for biogeographic studies. Hence, there is acute demand for common procedural approaches such as the European phenology system (Growth stages.., 2001; Meier et a l, 2009), which effectively uses a digital binary code and divides the entire growing season into 100 phases (stages). It does involve some challenges, but when, for instance, we see the code BBCH 07 - beginning of sprouting, BBCH 60 - first flowers open, BBCH 97 - end of leaf fall, it means the respective phase has begun in all species. A number of attempts have, in fact, been made in Russia to create a ‘code’ for phenological phases, but they usually used letter symbols and were not in line with other sources, causing much confusion. In keeping with A. A. Minin (2000), we believe a plant to have entered a phenophase when its signs are seen on at least some branches. Notes in phenology datasheets should include: • onset of a phase, i.e. the first day on which at least 10% of sampled plants have entered the phase, • peak - the day when at least 50% of sampled plants have entered the phase. Example: when inspecting a sample of 20 birch trees on April 27, firs t unfolded leaves were detected on two trees, on April 28 on six