Structure of the living ground cover in pine forests on dumps of Kuzbass
Revegetation of extensive damaged lands is a serious problem for areas of the Kuznetsk coal basin (Western Siberia). We considered the features of the living ground cover formation in pine plantings in the areas of mine dumps restoration. We conducted studies in 4 ecological and geographic zones: mid-mountain taiga, southern forest-steppe, northern forest-steppe and central steppe (here, the zones are presented according to the level of hydrothermic coefficient reduction). The aim of the research was to study the structure of the lower vegetative layer of age class II in pine stands growing on coal industry dumps. The even-aged homotypical pine stands, category I of the general vital state and bonitet classes I-II, were the objects of the research. Tests in 5-fold frequency were carried out; in four variants of crown closure, from 30 to 90%, with a step of 20% (See Table 1). We analyzed such parameters as taxonomic structure and projective cover of grass layer and moss layer, ecological and ecological and cenotic structures, and the weight of the living ground mass. Accumulation and data processing of field studies (2014-2015) were carried out by means of application programs IBIS and PAST. 95 species, 77 genera and 28 families of higher vascular plants make the taxonomic wealth of the studied territory. There are 89 angiospermous species, 4 gymnospermous species and 2 species of vascular cryptogam plants among them (See Table 2). The variants of the mid-mountain taiga ecological and geographic region are leading in the absolute number of species (58), exceeding other regions in this factor 1.5 times. The analysis of taxonomic structure shows that plant associations of pine plantings are in a dynamic status. A strong Asteraceae predominance (25% of species composition), the growth of Fabaceae rank, and the lowering of Poaceae rank (in comparison with natural meadow and forest communities) indicate this. Fabaceae predominance can be a feature of mesophytization of ecotops at restoration sections (in comparison with open spaces of dumps). The differences in floristic composition of plantings are a consequence of zonal features (See Fig. 1). In general, the low measure of similarity between variants demonstrates predominance of the randomness factor in case of the settlement of grass types, a dynamic status of phytocenoses of pine plantings, and the initial stage of their evolution. There are 3 groups in the ecological structure which reflect the relation of species to moistening: xerophytes, mesoxerophytes, and mesophytes (See Fig. 2). Specific zonal features of species composition of the studied regions show the data of ecological and cenotic analysis (See Fig. 3 and 4), however unification of the appearance of grass stands occurs due to a high role of ruderal species, especially in little closed stands (crown closure is 30-50%). The important quantitative feature of the living ground cover which reflects the impact of an edificator plant is the size of living above-ground phytomass. On the whole, this characteristic repeats the dynamics of the total projective cover. The crown closure has a much stronger influence on the size of the above-ground phytomass than the ecological and geographic location of the research area (See Table 3). The essential role in composing the living ground cover of plantings belongs to moss communities. In total, 7 species are found under the cover of plantings, Ceratodon purpureus is the most widespread cosmopolitan species. Formation of the living ground cover of pine plantings on coal industry dumps is influenced by zonal features. The factor of vegetative environment plays a predominant role in the formation of the structure and species composition. The crown closure of plantings defines quantitative characteristics: projective cover and phytomass. The рдрег contains 3 Тдbles, 4 Figores дrd 34 References.