???????????????? ?????? ??????????????? ?????????????? ??? ????????????? ???????? ???? ?????????????????? ????????? ???????????????????????

Анотація

Abstract. The basic indices of the sanitary state of Scotch pine stands on the land reclamation lands of the State Enterprise ???Sarny Forestry??? were determined. The purpose of the study was to determine the sanitary state of pine plantations of various species and compositions in conditions of drainage systems of the State Enterprise ???Sarny Forestry???. The research plan also intended to establish the patterns of the impact of adverse natural and man-made factors that predispose pine forest depression and provide recommendations for improving the sanitary state of pine plantations. The object of the research is the pure and mixed pine plantations of the III??XI age grades. The predominant type of forest vegetation is the moist pine site, which occupies a quarter of the area of the enterprise.

The sanitary state of pine plantations in the conditions of drained territories was investigated on trial areas, which lay on five transepts between drainage channels. In total, 20 test areas were laid in four on each transect. It has been established that in pure pine plantations, most of the declined trees, as well as deadwood of fresh and past years, are concentrated on test areas that are far from drainage channels, that is, with lower levels of water table. In the mixed pine-birch stands, this pattern cannot be traced, since a significant number of deadwood birch trees are located on plots located near canals.

The mixed pine-birch stands of the third grade of age are characterized by a higher index of sanitary state, which varies within 1.93??2.36 units. The satisfactory sanitary state of these plantations is explained by the largest number of drying and deadwood birch trees adjoining. The situation is somewhat better in pine-birch plantations of the 5th-grade age at transect 5, where the average weighted index of sanitary condition is 1.86 units.

The regularity of the deterioration of the sanitary state of pine stands from drainage channels to the central places between the channels is revealed. This tendency is especially clear in pine-birch plantings, where the sanitary index increases from 1.81 to 2.36 units. A similar trend in the increase of the sanitary index with removal from channels is observed in pure pine stands. In general, the sanitary state of pine plantations in conditions of meliorate systems is evaluated as satisfactory. In order to improve the state of the stands, it is expedient to carry out sanitary selective cuttings, with the removal, in the first place, of trees affected by endoscopes and pathogens, as well as declined and deadwood trees with lowering of planting density to standard values.