Species and coenotic composition of phytocoenoses in Jurassic clay dumps of the Callovian layer of the Mikhailovsky Mining and Processing Plant of Kursk Magnetic Anomaly

The paper presents the results of research on overgrowth rate in Jurassic clay dumps of the Callovian layer of the Mikhailovsky mining and processing plant of the Kursk magnetic anomaly with herbaceous and woody-shrub vegetation. The authors have revealed some features of dumps overgrowth of different dumping times (5, 15, 25 years) and the nature of various exposures of dumps overgrowth. The study has shown that by the age of 5 a pioneer grouping is formed on the Callovian clay, where the dominant species are the coltsfoot Tussilago farfara L. and the meadow horsetail Eguisetum pratense Ehrh. By the age of 15 a thicket-group community is formed, belonging to the category of simple, since it is represented by single species or has a bed character of overgrowth with a small number of weeds and meadow species. The authors have established that by the age of 25 the predominant types of overgrowth are group-thicket communities, where edificant species (the silver birch Betula pendula Roth and the common pine Pinus sylvestris L.) have a sparse distribution. It was found that the areas occupied by grassy vegetation on 25-year-old dumps in general have a bed character of overgrowth and are represented by monodominant communities of medicinal melon, which has a two-year period of development. At intervals of a year, with a dominance of the coltsfoot and the dandelion medicinal Taraxacum officinale L., the projective coverage reaches one hundred percent. A number of ruderal and meadow species (yarrow Achillea millefolium L., coltsfoot, narrow-leaved cypress Chamerion angustifolium L., forest parsnip Pastinaca sylvestris Mill., dandelion medicinal, sagebrush Artemisia compestris L., meadow bluegrass Poa pratensis L.) have a relatively sparse distribution. Additionally, the distribution of species depending on the exposure of slopes is described. The authors present species composition, projection coating and the number of plants and species per 1 m for all dumps. The dependence of the coenotic composition of vegetation on the age of dumps is established.