Current state of trees and shrubs vegetation conditional references linden-ash oakwoods flood places of Dniprovsk Prisamarya

Abstract

Natural oakwoods are considered one of the main centers of biodiversity of flora and fauna in Europe and an important agent of providing a wide range of ecosystem, sociocultural and economic services. But in the modern period, there is a decrease in the share of common oak natural forests in the forest reserves of European countries and various manifestations of their degradation. Floodplain forests form a particular value among natural oakwoods. They’re not only play an important role in the formation of vegetation and biogeocenotic cover, but also have a significant positive environment-transforming effect on soil-hydrological and mesoclimatic conditions. That helps to regulate the hydrological regime of river floods. An analysis of the current state of the tree-shrub vegetation of conditional reference linden-ash oakwoods of the central floodplain of the Samara River was conducted. They are a complex of forest vegetation component of Prysamary Dniprovskyi, the territory of which is reserved for the creation of a national nature park. The forest valuation indicators of stands of the main forest-forming tree species have been determined. According to the obtained data, the species composition of tree-shrub vegetation and the type of stand correspond to typical fresh central floodplain linden-ash forests. An increase in the share of participation in the tree stand of Acer campestre and a decrease of Tilia cordata are characteristic. Quercus robur and Fraxinus excelsior take a leading part in the formation of stocks of stem wood. It is determined that in the natural linden-ash oak centropopulation Fraxinus excelsior, Acer platanoides, Acer campestre, Ulmus laevis, Tilia cordata, Ulmus glabra, Pyrus communis, Ulmus minor belong to the normal type and are stable and capable of self-maintenance. The most active self-regeneration is recorded in Acer campestre. The population of Quercus robur is characterized as regressive with signs of disruption of natural regeneration processes and the absence of healthy undergrowth. Fraxinus excelsior, Acer platanoides, Ulmus laevis, Pyrus communis are distinguished by the highest indicators of vitality ((Ln) and according to the index of relative vitality their tree stands belong to the “healthy” categoty. The tree stand of Quercus robur belongs to the “weakend” category. Deterioration of the vitality of Quercus robur tree stands and disruption of its self-regeneration processes can potentially lead to a decrease in the edifying role of oak in fresh linden-ash forets of the valley complex of the Samara River. Also, it can lead to a transformation of their type of wood composition and a decrease in productivity. Major of environmental significance of the forest vegetation of this area requires systematic comprehensive monitoring studies to update current data on the state of unique natural oakwoods. The presented results are a continuation of the monitoring studies of natural reference central floodplain linden-ash forests and can become the basis for the development of differentiated methods of their preservation and restoration.