Nº 5 (2022)

In a comparative vein, the existing and potentially possible methodological methods for delimiting zonal-provincial associations of forest-bog and peat-bog complexes are analyzed. It is shown that on geomorphological differences of locations under conditions of continuous interaction with climate elements, soils and vegetation, their relatively autonomous development in time and space is carried out. On the example of the northern part of the Ob and Tom interfluve, in accordance with the criteria of such relative autonomy, natural indicator variations in the taxation and phytocenotic structure of indigenous marsh forests and, for comparison, dry valley pine forests are characterized. In the ranks of their modern typological and morphosculptural organization, causal relationships of ecosystem diversity and productivity with water and mineral growing conditions are considered, which clearly affect the composition of the age generations of the «mother» forest stands, undersized undergrowth and juvenile renewal groups. On the basis of the dimensions of the positive elements of the phytogenic micro- and mesorelief, large-hillock and cushion-like surfaces of oligotrophic and mesotrophic pine forests with mossy-lichen-shrub vegetation are typified, in peat deposits of which permafrost aquicludes and ice lenses-migratory are regularly localized. In especially moistened eutrophic pine forests with grass-mossy and low-grass vegetation, the phytogenic relief is considered in the system of different-height, scattered and merged tussocks, as well as near-stem mounds, which are formed by frameworks of skeletal roots draped with coniferous-leaf litter, grass rags, green Bryidae Engl. and hypnum Hypnales W. R. Buck et Vitt tows mosses. Taking into account these and a number of other factors, the trend of ambiguous settlement of self-sowing and pine Pinus L. undergrowth under the canopy of «mother» forest stands is estimated. Phytocenotic and inventory indication of pine forests, based on the system-sampling method of assessment, expands the understanding of the comparative range of variability in the structure of both marsh and upland pine forests that have reached the climax or approached the stages of self-development.

The results of long-term studies of taxonomic diversity and ecological and trophic features of the mycobiota of urban birch forests of Krasnoyarsk, which are subjected to an average degree of recreational load, are presented. 234 species of macromycetes have been identified, of which only less than half are found regularly, most of them are detected rarely or singly. The main part of the mycobiota, rich in single-species taxa, is made up of fungi of the order Agaricales Underw.; in terms of the number of species in the family spectrum, the families Russulaceae Lotsy, Agaricaceae Chevall., and Inocybaceae Jülich. are the leaders. The generic spectrum is dominated by Russula Pers., Inocybe (Fr.) Fr. and Mycena (Pers.) Roussel. The ecological and trophic structure of the mycobiota is dominated by xylotrophs, mycorrhiza formers, and humus saprotrophs. Widely specialized xylosaprotrophs predominate over xyloparasites, which are rarely found on living trees. Among the mycorrhiza-forming species, the proportion of representatives of the Russulaceae and Inocybaceae families is high. Among the humus saprotrophs, there are species characteristic of both forests and open habitats. The presence of a large number of synanthropic species in the dominant taxonomic and ecological-trophic groups of macromycetes indicates a pronounced impact of recreational pressure on the formation of mycobiota in urban forests. On the fallen birch, Hericium coralloides (Scop.) Pers, listed in the Red Data Book of Krasnoyarsk Krai, is regularly found. Several more rare species of fungi subject to protection were identified in the study area in previous years.

Fossil wood that is ca 7 million years old from Bükkábrány (Hungary) was analyzed by thermogravimetry (TG), differential scanning calorimetry (DSC) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) to evaluate alterations of its chemical composition. A wood sample of bald cypress ( Taxodium distichum (L.) Rich.) from West Hungary was taken as a reference. The fossil wood was characterized by higher contents of total carbon (58.05 %) and total nitrogen (0.44 %) compared to recent wood. TG of fossil wood showed a high heterogeneity of wood substance, significant loss of polysaccharides and enrichment by lignin including more thermally stable components (> 500 °C). The enthalpy change (∆H) of combustion (thermo-oxidation) for fossil wood was significantly higher than for recent wood (-18.17 kJ/g vs. -11.41 kJ/g). Py-GC/MS analysis of fossil wood showed a significant depletion of polysaccharide pyrolysis products and an increase in lignin pyrolysis products compared to recent wood. The pyrolytic H/L ratio indicates a preferential loss of polysaccharides in fossil wood. Polysaccharide pyrolysis products were rare and represented mainly by levoglucosan. Lignin also underwent substantial changes. A dramatic decrease in monomers, an increase in short side chain compounds and the presence of demethylated/demethoxylated compounds in the composition of lignin pyrolysis products are indicative of lignin alteration (degradation). Moreover, a high abundance of styrene, cresols, phenol and phenolic compounds was observed.