FOREST LIVE COVER COMPOSITION IN 30-YEAR SPRUCE PLANTATIONS (GRASS- PLEUROCARPOUS MOSS FOREST TYPE) IN THE MIDDLE URALS

Abstract

Introduction. In modern plant sociology, species diversity is one of the most intensive developing courses. It is considered in depth in forest and meadow plant formations of natural environment and it is poorly studied in the artificial dendrocenoses covering dozens mln.ha  in Russia. Creation of data base in composition of forest live cover and its phytomass in forest ecosystems of artificial origin is a vital task for sylviculture and botany. The goal of the research is to study the species composition of forest live cover and phytomass of field cover under the canopy of 30-year Spruce plantations (grass- pleurocarpous moss forest) in the Middle Urals. Objects and methods of research. Species composition   of forest live cover was studied with standard methods for botany and sylviculture on the lot of 30-year plantations of Siberian spruce (grass- pleurocarpous moss forest type). The research was carried out in the inter-row spacing for plantations with weak (0,3-0,4), middle (0,5-0,7) and high (0,8-1,0) canopy closure. Results. Forest live cover in the studied lot is represented with 105 species (91 species are herbaceous plants, 2 – subshrubs, and 12 – moss). Herbaceous plants are of 37 families. Moss is represented with 10 families. Subshrubs belong to one family. Maximum species diversity (99 %) in the grass cover composition is observed within 0,5-0,7 range of canopy closure. At that, herbaceous plants are not in abundance. The maximum height, abundance, and bulk of many species of herbaceous plants were found in the group with weak canopy closure (0,3–0,4). In the group with high canopy closure, many plants have been conserved (57 species), but the plants were in extremely depression state, located unevenly. In this place, the parcels of new species (Asarum europaeum L. and Oxalis acetosella L.) start to form. There are always these parcels in dark coniferous forests. Among the studied plants, 79 species are considered to be medical plants, 3 species are rare for Sverdlovsk Region. Conclusion. High canopy closure dims the soil and increase the area, covered with intense tree waste. It results in species composition impoverishment for grass- fruticulose layer under the canopy as well as in the decrease of occurrence, height, abundance, and phytomass of plants. To support the medium canopy closure in the spruce culturecenoses, it is important to hold the silvicultural measures, enabling improvement the stands productivity and conservation high level of species composition in the grass- fruticulose layer.