RESILIENCE OF PINE PLANTATIONS IN THE CONTEXT OF GLOBAL CLIMATE CHANGE

Abstract

Global climate change has a direct impact on local biota, and in particular on the sustainability of coniferous stands. After 2010, intensive drying of pine plantations of Ukraine began as a result of mass reproduction of apical bark beetles (Ips acuminatus Gyllenhal, 1827) and six-toothed bark beetles (Ips sexdentatus (Börner, 1776)) in a complex with other xylophages. In the north of Zhytomyr and Kyiv regions, mass drying of pine trees began in 2015, however, it was most intense in 2017. Our research involved surveying plantations and planting test areas in areas affected by xylophages, establishing a complex of trunk pests that damage the tree stand, analyzing weather and meteorological factors that could contribute to the development of xylophages, and identifying other threats to pine tree stands. During 2016-2018, test areas were laid in the Polissky Nature Reserve and a threat analysis was carried out. According to the results of research, from the beginning of mass drying until 2018, the most aggressive pest of ripening and ripe pine stands was the apical bark beetle, after which the trees were inhabited by other xylophages. The determining factor of this phenomenon was climatic changes, in particular the temperature regime and the amount of atmospheric precipitation. The analysis of meteorological factors showed that starting from 2009, a deficit of precipitation was created, which until mid-summer 2018, combined with high summer temperatures, contributed to the weakening of stands. Mild winters, the absence of long-term frosts with temperatures close to -20°C contribute to a high level of pest survival in the crown, and long-term thaws allow pests to be additionally nourished. An increase in the growing season contributed to the appearance of additional generation of bark beetles. Since 2018, as a result of climate change, the number and scale of forest fires has increased. A review of spirogenic stands showed their active involvement with xylophages during the next three years after the fire. More resistant to the spread of pests and the spread of fires were mixed stands with a significant participation in the composition of hardwood plantations. The formation of mixed plantations can significantly affect the preservation of pine trees in conditions of climatic changes.