Scots pine (Pinus sylvestris L.) seasonal growth at different stages of ontogenesis in Taiga zone (Karelia)

The studies were conducted in 2014–2015 in southern Karelia (middle taiga subzone). The aim of the research was to study the seasonal growth of shoots, needles and trunks in young (22 years old), middle-aged (55 years old) and ripening (86 years old) stands of Pinetum vacciniosum. The study found that the dynamics of the seasonal growth of vegetative organs in trees during ontogenesis varies somewhat. The beginning of the growth of shoots, needles and trunks does not depend on the age of the tree. The formation of wood cells in the lower part of the trunk in relatively young trees begins on days 8–12 earlier. The end of the growth of shoots and needles in trees of different ages is observed at the same time. The formation of trunks in relatively young stands lasts for 18–25 days longer. The growth rate of the trunks decreases with the age of the tree, the needles — increase, and in shoots it reaches its greatest value in middle age. On average, the annual growth of trunks in young, middle-aged and ripening stands is 2,54, 2,11 and 1,06 mm, respectively, needles — 11,3, 15,5 and 18,8 mg, shoots — 35,1, 38,4 and 34,4 cm. Differences in annual growth of shoots and needles are associated exclusively with the change the intensity of their growth, and the trunks, in addition, and with a difference in the duration of their formation. The features of the curves reflecting the dynamics of growth of vegetative organs in stands of different ages generally remain unchanged, the culmination of their growth being observed almost simultaneously.

CHANGE OF HEAT FLUX AT THE WATER-BOTTOM SEDIMENTS BOUNDARY IN A SMALL LAKE DURING THE YEAR

The features of the variability of the heat flux at the boundary of the water column with bottom sediments in the central part of the small polymictic Lake Vendyurskoe (southern Karelia) were analyzed according to the data of year-round temperature measurements from November 2018 to October 2019. It was shown that the heat flux directed from the bottom sediments into the water reached 6–8 W/m2 in the pre-ice period and at the moments of ice formation and breaking, and did not exceed 1 W/m2 during most of the winter. A week after the ice-off (May 3–4, 2019) the water column was completely mixed, the heat flux changed its sign, and heat accumulation in the upper layer of bottom sediments began. The heat flux directed to bottom sediments was 4–6 W/m2, periodically increasing to 8-12 W/m2 from mid-May to late July and from the second decade of August to the first decade of September. Against the background of a prolonged cooling during the first ten days of August, the heat flux changed sign with daily frequency, the amplitude of daily fluctuations reached ± 2.5 W/m2. Autumn cooling of the Lake Vendyurskoe began in early September 2019, the heat flux sign changed on September 14–16, 2019.

The distribution of village names based on pre-Christian Finnic personal names in the northern Baltic Sea area

The article studies pre-Christian Finnic anthroponyms and their spread in the northern Baltic Sea area at the end of Middle Ages (c. AD 1520). This is done by analysing village names based on pre-Christian Finnic personal name elements. The primary research material consists of various editions of documents from the 15th and 16th centuries. The analysis demonstrates that village names based on pre-Christian Finnic anthroponyms are most densely located in Varsinais-Suomi, Häme, Northern and Eastern Estonia, Southern Karelia, the Karelian Isthmus and Eastern Ingria. The first four areas are home to significant Iron Age settlements. It seems that the use of the pre-Christian Finnic name elements under investigation originally started in these areas and spread eastwards.

Distribution records of aphids (Hemiptera: Phylloxeroidea, Aphidoidea) associated with main forest-forming trees in Northern Europe

We report records of 25 species of aphids collected from four species of woody plants (Pinus sylvestris, Picea abies, Betula pubescens and B. pendula) at 50 study sites in Northern Europe, located from 59° to 70° N and from 10° to 60° E. Critical evaluation of earlier publications demonstrated that in spite of the obvious limitations of our survey, the obtained information substantially contributed to the knowledge of the distribution of aphids in North European Russia, including Murmansk oblast (103 species recorded to date), Republic of Karelia (58 species), Arkhangelsk oblast (37 species), Vologda oblast (17 species) and Republic of Komi (29 species). We confirm the occurrence of Cinara nigritergi in Southern Karelia; Pineus cembrae, Cinara pilosa and Monaphis antennata are for the first time recorded in Norway.