The article focuses on the results of experimental research held on the territory of the Right-Bank Forest-steppe of Ukraine. Quantitative and qualitative indices of the fraction of forest litter, its fractional composition depending on forest planting conditions are considered.

According to our research, it is observed that there is no significant difference in terms of precipitation of the oak leaves and the single-pointed hawthorn leaves. At the same time, the intensity of the decomposition of organic precipitation is uneven. Single-pointed hawthorn leaves decompose for one year at a sufficient amount of moisture and heat. So, in spring and in the first half of summer (May, June) under the single-pointed hawthorn tree layer of the litter decreases, and until autumn, only spots of leaf petioles and branches remain from the organic precipitation of the single-pointed hawthorn. The share of organic precipitation of one-point hawthorn in the total stock of litter until the beginning of autumn is about 10-15 %. At this time, the morphological features of oak leaves in the litter remain during the year after they have fallen. In spring and in the first half of summer, the strength of the litter under the oak decreases as a result of the decomposition. However, since July, the stock of litter is increased due to precipitation leaves from the bottom of the crown. From May to July there is much fewer leaves in the forest precipitation of all studied species (except single-pointed hawthorn) than other fractions, and from August to November, vice versa.

In November, hawthorn leaf litter is almost absent, while, according to our research, the quantity of it is 56 % in October. This discrepancy is explained by the various climatic areas of the region of research and the meteorological conditions of those years when the experiments were carried out. The first leaves fall in May, it increases in October, and in November it is completed. As a result of the blossoms fall in May, the amount of the mixture increases significantly and it is 179.1 kg on average (leaves – 29.5, branches, bark, stem– 70.9 %). The weight of all precipitation in June is 95.4 kg (42.6 % and 57.4% respectively).

In July, the fall of oak leaves noticeably increases. At the end of the month, the first damaged fruit begins to fall down (1.3 %). In September, the defoliation increases and amounts 1143.1 kg (leaves – 78.9 %, fruits – 4.1 %, branches, bark, peduncles – 17.0 %).

The defoliation of one-point hawthorn begins in July and August and it ends in November.

The largest amount of single-point hawthorn stock is observed in October. In the fresh and transient from fresh to dry oak groves leaves and branches of the hawthorn single-pointed plantations begin to fall in June, in dry oak groves leaves and branches begin to fall in August.

The noticeable deposition of oak leaves, branches and other organs is observed in July and August. In general, the stock of litter under the crown of the hawthorn single-pointed in fresh, transitional from dry to fresh and dry oak groves significantly increase from October.

According to our research, a mixture of organic precipitation of one-point hawthorn in the oak barley increases the nutrient content of the litter. Thus, the organic debris of the one-point hawthus decomposes faster than the organic oats of the oak, and their mixture accelerates the mineralization of the litter.

The organic lump of the single-point hawthorn differs not only in the rate of decomposition, but also in the higher nutrients content (nitrogen, phosphorus, potassium and calcium) than in the fall of oak and common hornbeam.

The features of accumulation of litter during the year are investigated. It was established that 10 % of organic precipitation of hawthorn single-pointed admixture to organic precipitation of ordinary oak accelerates the decomposition of the ordinary oak litter 1,4–1,5 times.

The conclusion is made of the positive effect of the single-point hawthorn on the rate of ordinary oak litter decomposition and, consequently, leads to the nutrients increase in the soil.

Key words: forest litter, single-pointed hawthorn, ordinary oak, decomposition of litter, stock of litter, forest plantations.