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.

192 A phenological atlas of plants Complete snow melt in fields. The date on which no snow was found remaining in open sites (fields) in the inspected surroundings. Some snow may however persist in gullies, low and shady sites. River ice break-up. Very often, one or several ice runs happen before full-scope break-up and wash. Record the dates of the first ice run, onset and end of break-up. Specify the river name. Peak water level in a river during spring tide. The peak level date is recorded. Data are borrowed from gauging station or post. Where the observations are not at a gauging station or post, a wooden rod marked off in centimeters should be fixed in advance, not later than on the first day of water level rising, to a bridge support or pier. To keep the rod undamaged by drifting ice it should be installed (or painted on stone bridge support with asphalt varnish) with markings streamwise, i.e. the observer should be looking upstream. Where there is no bridge nearby, a rod can be fixed to or painted on a sturdy object (pillar, pile, tree) that is annually flooded by spring tide. Ice cover disappearance from reservoirs. The date when the ice had fully melted. Specify the type of reservoir (lake, impoundment, pond). If a lake, specify its name. Snow disappearance from forest. Specify the type of forest (spruce, pine, etc.). Disregard isolated snow patches. Last air frost. The last date in spring (or early summer) when air tem perature was 0°C or below. Specify frost-inflicted damage to plants. Last ground frost. Determined with a minimum reading thermometer