Anatomical and Morphological Features of Scots Pine Heartwood Formation in Two Forest Types in the Middle Taiga Subzone

Currently, there is no consensus on how growing conditions affect the heartwood formation in Scots pine. Comparing the results obtained by different authors is difficult due to methodology differences and poor descriptions of the objects used. We selected two sample plots in (1) a blueberry pine forest on nutrient-rich and moist soil and (2) a lichen pine forest on nutrient-poor and dry soil and performed their detailed characterization. The sample plots were located 22 km apart in the middle taiga subzone (Karelia Republic, northwest Russia). In each sample plot, we selected five dominant trees (model trees), from which we took cores at different trunk heights (0.3, 1.5, 4.5, 7.5 and 10.5 m). The cores were treated with 2,6-dichlorophenolindophenol to identify the heartwood zone. Additionally, samples were taken to study the structural features of the transition zone between sapwood and heartwood. In both forest types, the number of heartwood rings depended on the cambium age, and the patterns of parenchyma cell death did not differ in the transition zone. These facts point to a predominantly internal regulation of the heartwood formation in Scots pine. The heartwood radius and its proportion on the cross-sections were significantly higher in the blueberry pine forest than in the lichen pine forest, despite the relative values of the annual ring width. Further research is needed to develop successful Scots pine heartwood width models under a wide range of conditions.

Lateral and radial geochemical structure of bog catena soils (on the example of middle-taiga bog system of Western Siberia)

Lateral and radial geochemical structure of bog catena soils of Western Siberia middle-taiga subzone has been investigated on the base of B, Na, Mg, Al, P, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Rb, Sr, Y, Zr, Mo, Cd, Sb, Cs, Ba, Hf, W, Pb, Th, U and lanthanoides content. Bog catena is characterized with high contrast of radial distribution of most studied elements. Lateral differentiation is significantly lower than radial one and is monotonous for most elements. In bog catena soils of Western Siberia middle-taiga subzone there are investigated correlations between elements content and soils characteristics that are mainly determined by specific peculiarities of ecosystem development.

Growth, development, morphology and biochemical characteristics of Solidago canadensis L. plants when introduced in the middle taiga subzone of the Komi Republic

The paper presents the results of a long-term study of four samples of Canadian goldenrod ( Solidago canadensis L.) of different geographic origin introduced in the middle taiga subzone of the Komi Republic. Under cultural conditions, the species is highly resistant and longevity (up to 18 years). It has been established that with the introduction in the North, reproduction of the Canadian goldenrod is possible by vegetative means, as well as from seeds of foreign origin. The mass transition of plants grown by seedlings to the generative period occurs in the third year of life. According to the flowering rhythm (July 31 - September 25), the species is classified as a mid-summer-mid-autumn plant. Fruiting of plants is interrupted by frost, full-fledged seeds are not formed. The morphological features of the generative shoot have been studied. The plant height in culture reaches 143-155 cm. The number of leaves on the stem is 63-101. The floral part of the shoot (inflorescence) 30-39 cm long is formed from the axils of 41-49 leaves and consists of 21-41 paracladia 8-13 cm long. The number of baskets on one shoot in different specimens of Canadian goldenrod varies from 2700 to 4200. The content of nitrogen mass fraction (1,8-3,0%) in the aboveground raw phytomass of Canadian goldenrod has been studied for the first time and the quantitative and qualitative composition of amino acids in plant proteins has been determined. The total content of amino acids in the plant raw material of Canadian goldenrod has varied from 7,9 to 15,1% over the years. In the aboveground phytomass of plants, 17 amino acids have been found and determined, including 7 irreplaceable ones. The share of essential amino acids has averaged 37% of the total. The highest rates of equity participation have been noted for the following amino acids: proline, glutamic, aspartic, lysine, leucine, valine, alanine, arginine and glycine - 13,2; 11,0; 10,8; 8,4; 8,0; 5,9; 5,8; 5,7 and 5,2%, respectively. In the conditions of the North, biochemical studies of this species have been carried out for the first time. The content of flavonols in the aboveground raw phytomass of Canadian goldenrod have been 4,5-5,7% and met the requirements for medicinal raw materials (more than 3%). The yield of essential oil and its component composition have been determined. The EO content in the aboveground phytomass of plants has varied from 0,85 to 1,7% in terms of absolutely dry raw material. In the composition of EM, 39 components have been reliably identified, nine of which have been attributed to the main ones. The dominant compounds are: -pinene (up to 43,9%), myrcene (up to 18,2%), limonene (up to 13,2%), -3-carene (up to 12,0%); from sesquiterpenoids: germacrene D (up to 54,3%), bornyl acetate (up to 5,8%), geranyl acetate (up to 2,4%), cadinadiene (up to 2,0%), sesqui-fellandrene (up to 1,4%).

Raw materials of Hypericum perforatum L. of different geographical origin in the conditions of introduction

The results of studying the growth, development and formation of the raw phytomass of Hypericum perforatum plants of different geographic origin during the introduction in the middle taiga subzone of the Komi Republic are presented. Seven samples of Hypericum perforatum were examined, including two cultivars: Zolotodolinsky and Solnechny. A sample (Tallinn No. 885) was identified, which differed in earlier dates of the onset of phenological phases. Hypericum perforatum plants under culture conditions in the middle taiga subzone of the Komi Republic are characterized by a stable developmental rhythm. It has been determined that the number of generative shoots in Hypericum perforatum increases with age. So, in two-year-old plants this indicator was 3-4, in four-year-old plants - 18-26 pcs. per individual. It has been established that from the second year of life, with the seedling method of growing, Hypericum perforatum plants are able to form high yields of medicinal raw materials. As a result of an assessment of the productivity of samples of cultivar Solnechny and sample from Barnaul.

Dynamics of Carbon Stocks in the Formation of Forests on Post-Agrogenic Lands

Carbon stocks were calculated in different components of bigeocenosis (soil, living ground cover, forest floor, undergrowth, underbrush and forest stand) using the example of a selected chronosequence of fallows (4 sample areas of different age, yrs: 16, 25, 63 and 130) in the Kargopol district of the Arkhangelsk region (middle taiga subzone, residual carbonate soils). The structure of carbon stocks of the forming plantations and its changes with the fallow age is estimated. It was found that a natural increase in carbon stocks and its redistribution between the soil and the forming phytocenosis occurs in the process of succession during the afforestation of arable lands. In plantations growing on young fallows, more than 86 % of the carbon stock is represented by carbon from the arable soil horizon. During the colonization of the fallow by forest vegetation the share of this pool decreases and already in the middle-aged 63-year-old forest it is 22 %, and in the mature 130-year-old forest it is only 7.6 %. In the structure of the total carbon stock in the middleaged plantation, the share of the stand reaches 69 %, and in the mature 130-year-old stand it is already 90 %. In plantations on young fallows, the structure of the main components of biogeocenosis (soil carbon, ground cover carbon and tree layer carbon) is characterized by a ratio of 9:1:0, whereas in plantations on old fallows of 63 and 130 years it is 2:0:8 and 1:0:9, respectively. The undergrowth and underbrush of the studied chronosequence are characterized by the small shares of carbon, which do not have a significant value in the structure of the ecosystem carbon pool. Forest floor in forming forest stands contributes significantly to the carbon structure of the biogeocenosis, although the total biogeocenosis carbon pool is 3–4 % and does not contribute to an increase in soil carbon stocks. In the system “soil – forest floor – living ground cover” the share of soil carbon decreases from 91 to 76–77 % with the increase in the age of plantation, while the share of formed forest floor in the middle-aged and mature forest is 16 and 20 %, respectively. In plantations on young fallows the ratio of these components of biogeocenosis is 9:0:1, whereas on old fallows it is 8:2:0. Leaving arable land on residual carbonate soils for self-overgrowth with forest vegetation and formation of forest plantations on them in the middle taiga subzone will lead to a gradual decrease in the carbon pool in the soil, but will contribute to the sequencing of carbon in the phytomass of perennial woody vegetation and in forest floor. These two components of biogeocenosis will serve as a sequenced carbon depot, supporting the biological cycle.