Seasonal dynamics of the fractional composition of forest litter of Holosiivskyi National Nature Park

Leaf litter is an important structurally fucnctional element of forest ecosystem, dynamic processes in which create a connection between phytocenosis and edaphotope. Accumulation of litter material and its decomposition rate characterize intensity of substance circulation in forest ecosystem. The present article deals with the results researching of the peculiarities of the forming and decomposition of soil litter layer in the hornbeam oak in the conditions of Holosiivskyi National Nature Park (Kyiv) were examined. Its considerable sizes on the north slope of ravine coast system (16,4 t/ha in autumn, 4,3 t/ha in the summer) were determed. Analysis of litter supply at the end of abscission showed a lack of significant differences in different sections of the terrain (12,3–16,4 t/ha). During the winter period, litter volumes are significantly reduced due to intensive mineralization processes under the snow cover. Most intensively, these processes take place in areas of the slope. Fractional composition of the litter did not generally depend on the location of the experimental area by relief elements. A dominating faction in autumn and spring was fall (65–69 % of the total mass). In the summer, a portion of dust (38-46 %) increased. The smallest number of branches was observed in autumn and winter, their scope was between 11-22 % in all research areas. The maximum amount of branches was observed at all areas in the summer. Their volume was 27-49 %. The scope of seeds and its residues was insignificant and amounted to 1-3 % during the year. The speed of mineralization of cellulose by an application method with the use of filter paper is determined. The rate of decomposition of cellulose in the conditions of the southern and northern ravine slope turned out to be similar to the maximum in March and July-August.