The formation of herbage covers in Scots Pine plantations on recultivated lands of Semenivsko-Golovkivskiy lignite open-cut

Abstract

The studies were conducted in the 20-year-old plantations of Pinus sylvestris L. cultivated on recultivated lands of Semenivsko-Golovkivskiy lignite open-cut. The sample areas are located within five types of edaphic variety of technosol that determines the specificity of forest growth conditions and development of forest plantations on man-made slope of 5-8º. Type 1 is located on a plateau. The edaphotope is represented by sandy loam solid with mechanical impurities of rippled clays (0-85 cm) in the upper layer, and sand one deeper. Type 2 is located on the upper third of the slope. The edaphotope is represented by 0-20 cm of loessial clay loam, 20 cm and deeper there is a medium clay. Type 3 is located on the middle third of the slope. The top layer of 0-10 cm consists of humus; heavy loam is 10 cm and deeper. Type 4 is located on the lower third of the slope. The edaphotope is represented by light and medium clays of different colors; below 130 cm brown coal is found throughout the profile. Type 5 is located in the valley line. Edaphotope is presented by the mixture of heavy clay loams, red-brown and coal clay; below 120 cm throughout the profile there is the formation of brown coal. Humidification conditions are atmospheric.
 The research results have shown that the formation of grass stand in the Scots Pine plantations depends on number of factors, such as topography, humidification conditions and availability of nutrients, planting density, lighting conditions, etc. The grass stand, formed in the pine plantations is dominated by perennials (78-93 %). Climate morphs are represented by hemicryptophytes (63-79 %). Among heliomorphs, it is observed fragmented dominance of species, partly demanding to light (scioheliophyte) over light-demanding ones that is connected with the increase of density of planting. Mesotrophic group of plants dominates among trophomorphs. Depending on the edaphic conditions, the role of oligotrophic and megatrophic species is growing. The vast number of species among cenomorphs on all plots are the plants that belong to different groups of stepants and ruderants. Most species are pollinated by insects (69 – 79 %) and are spread by the spreading diaspore with elastic stalks by shocks (42 – 53 %).
 Summarizing the research results, it should be noted that, in addition to the influence of woody vegetation on the lower tiers of biogeocenoses, edaphic conditions are of great importance for their formation, as well as elements of the landscape, both created initially and formed as a result of the gradual fragmentary subsidence of the territory of the dump. These factors regulate the ratio of different groups of biomorphs, climamorphs, trophomorphs, hygromorphs, heliomorphs and cenomorphs in the grass stand. Climatic conditions, influence of surrounding phytocenoses of undisturbed lands set the direction of succession on the way of formation of zonal grassy group.