Soil conditions of biocenoses Quercus pubescens Willd. of the Southern coast of Crimea

The study was conducted in the biocenoses of Quercus pubescens on the Southern Coast of Crimea. Six sample plots were established in the western, central, and eastern parts of the study area. The soils are predominantly brown, weakly developed on eluvium-deluvium of limestones and clay shales, while at “Cape Martyan” they are brown reddish-brown soils (Terra Rossa) formed on a thick layer of leached weathering products of Upper Jurassic limestones. The study examined the structure and composition of the phytocenosis, taxation characteristics of the stands, and specific soil conditions. It was revealed that the most stringent conditions for the characteristics of the quality of the soil environment are currently developing in the western part of Q. pubescens growth on the Southern Coast of Crimea. The soil under Laspi and Kastropol plantings have the lowest humus concentration and moisture content. In the central part of the Q. pubescens forest, with some improvement in soil conditions, the general specificity of changes in the quality of the soil environment is very close to the plantings of the western territories. It was found that the growth and development of Q. pubescens stands on Cape Ai-Todor are largely determined by the seasonal dynamics of soil moisture. The relatively high moisture content in the soil during the first months of vegetation has a positive effect on the growth of Q. pubescens; and its sharp decrease in the second half of summer to values, close to the indicators of the biocenoses of the western part, shows a stressful effect on the condition of the forest stands on Cape Ai-Todor. In the eastern part of Q. pubescens habitat on the Southern Coast of Crimea, the underlying bedrock has a significant effect on soil conditions. Gabbro-diabase of the Ayu-Dag and Kastel laccoliths affects soil acidity, features of humus formation and accumulation. It is shown that dense gabbro-diabase layers increase moisture supply of Q. pubescens stands in the Ayu-Dag and Kastel ecotopes. It is concluded that the total cutting of primary Q. pubescens stands on the Southern Coast of Crimea in the past determined the deep degradation of the structure and composition of plant communities, the formation of low-productivity coppice plantations in these areas. One of the causes of destructive phenomena in the development of Q. pubescens biocenoses is a change in the water balance of the soil environment. The growth potential of Q. pubescens coppice stands on the Southern Coast of Crimea is currently provided by the powerful root system of the parent tree stand, which continues to function.