Stocks of litter and its morphological and fractional composition in Pinus pallasiana D. Don plantations at the Kryvyi Rih iron ore dump

Aim. The article aims to establish the morphological and fractional composition and stocks of a litter of pine plantations of Pinus pallasiana D. Don on the Kryvyi Rih iron ore dump depending on the relief conditions (different exposition and steepness of the slopes of the dump berms). Methods. The thickness, stocks and fractional composition of the litter were studied according to generally accepted methods (Vorobeychik, 1997; Rodin & Bazilevich, 1965). The litter was collected at five sites in 10 replicates (a total of 50 samples). According to the recommendations of L. O. Karpachevskiy (1968) active and inactive fractions of litter had been distinguished. The magnitude of the fall-litter coefficient and the intensity of the cycle were determined by the guidelines of L. Ye. Rodin, N. I. Bazilevich (1965). The thickness of the litter was ascertained according to the classification of L. G. Bogatyriov (1990). Results. We confirmed that the litter of pine plantations on the dump is characterized by different degrees of thickness. The accumulation of mortmass in pine stands varies in intensity – the most considerable rates was noted on the plateaus of the second and third berms – 6216.7 and 4748.1 g/m2, respectively, and the smallest ones – on the slope of the second berm – 1913.5 g/m2. The litter in 40-year-old pine plantations on the dump has a three-layer structure and only on the slope of the third berm is two-layered; it is characterized by different degrees of thickness: from 7.8 cm on the plateaus of the second and third berms to 3.9 cm on the slope of the second berm. It was found that an enormous contribution to the formation of litter was made by fragments ranging in size from 0.5 to 5 mm, the share of which could be 78.5%. The central part of the stocks of all studied litters in P. pallasiana plantations is the active fraction – from 74% to 98.7%. Conclusions. Plantations of P. pallasiana on the iron ore dump of Kryvyi Rih form significant stocks of litter. Thus, organic matter, thereby significantly improving the ecological and edaphic conditions for the development of biogeocenotic processes in these radically changed human-made ecotopes.