Variation of ground cover and forest litter phytomass stocks in pine forests on automorphic soils (Republic Of Karelia)

The influence of the type of forest vegetation and the phytogenic field of pine on the parameters of forest litter (thickness, stock, actual acidity) and phytomass of the components of the ground cover in lingonberry and bilberry pine forests on automorphic soils is studied. The highest values of phytomass (absolute dry mass) were found in communities of bilberry pine forests on sandy soils (596 ± 67 g/sq.m.), and the lowest in bilberry pine forests on two-layered deposits (460 ± 83 g/sq.m.) due to a lower presence of mosses in the ground cover. In all types of forest, the average values of aboveground phytomass (in total, herb-dwarf shrub and moss-lichen layers) exceeded the underground one. At the same time, the underground phytomass was on average 1.4–2.6 times higher than the mass of the herb-dwarf shrub layer, depending on the type of forest. The type of forest influenced the phytomass of the moss-lichen layer and the characteristics of the forest floor. The lowest indicators of litter thickness and stock were observed in the driest conditions of lingonberry pine forests (less than 5 cm and 39.6 ± 2.9 t/ha), and the highest (5–10 cm and 58.1 ± 5.6 t/ha) – in bilberry pine forests on two-layered deposits. The pH value of the forest floor also depends on the forest type: the lowest values are typical for lingonberry pine, and the highest – for bilberry forest. Differences in the phytomass of the underground parts of the herb-dwarf shrub layer, aboveground phytomass, mass of green mosses, dwarf shrubs and bilberry in the inter-crown and under-crown areas were revealed. Under the Scots pine crowns, the mass of dwarf shrubs is lower and the mass of green mosses is higher, compared to the inter-crown areas.