Наукові праці Лісівничої академії наук України (Jun 2021)
Climatic signal in the regional tree-ring chronology of Pinus sylvestris L. in the Left-Bank Forest-Steppe
Abstract
Knowledge of stands response to past environmental conditions can help predict how forests may respond to future climates. The climate influence on the radial growth of Pinus sylvestris L. in the stands of the Left-Bank Forest-Steppe, which grow which grow the weak sod-podzolic soils has been studied. Standard dendrochronological methods are used. A regional tree-ring chronology of Scots pine has been created, which consists of 80 individual tree-ring series and is based on 6 local tree-ring chronologies, which contain 5424 layers of annual wood. Based on this series, the RESIDUAL index series was developed, from which the age trend was removed, which made it suitable for further in-depth dendroclimatic analysis. The reference years of minimal growth (1936, 1942, 1954, 1975, 1979, 2000, 2005, 2009 and 2012) were revealed, during which the width of the annual wood layers was lower than the corresponding values of the previous year by 20-46%. Radial growth during these years was limited by precipitation, high temperatures of the growing season, extreme winter and early spring temperatures. The years of maximum growth (1935, 1943, 1953, 1988, 2004, 2011 and 2014) were characterized by a favorable ratio of temperature and moisture. Until 1979 during the minimum pointer years, radial growth was limited mainly by low temperatures and droughts, but after 1979 -only droughts and warm winters. Using the RESPONSE program with correlation and regression analyzes between the radial tree growth of Scots pine and climatic factors revealed that in the second period (1989-2017) compared to the first (1960-1988) the negative impact of temperatures and the positive impact of precipitation during April-August on the radial growth. In the first period, the positive effect of precipitation during the growing season lasted a shorter period - only June-July. In the second period, the temperatures of June-December of the previous year had a stronger effect on the radial growth of the current year in contrast to precipitation, the impact of which, on the contrary, decreased. Thus, the radial tree growth of Scots pine developed for the Forest-Steppe is suitable for further dendroclimatic analysis. The pointer years of minimal growth were revealed, which were characterized by a deficit of moisture during the growing season and extreme summer, winter and early spring temperatures. The years of maximum growth were characterized by a favorable ratio of heat and moisture. A comparison of the response of radial growth of Scots pine to climate variation during 1960-1988 and 1989-2017 revealed an increase in the trees sensitivity to climate change. An increase in the significant correlations the radial tree growth of Scots pine and climatic factors in the second period compared to the first, indicating a weakening of pine stands and a possible some deterioration in radial growth in the coming years. However, given the plasticity of Scots pine and its adaptation to climate change at the present stage, we can recommend planting Scots pine in the stands of the Left Bank Forest-Steppe.
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