Наукові праці Лісівничої академії наук України (Jun 2020)
Radial growth of Quercus robur L. response to climate change in Polissya and Forest-Steppe
Abstract
The objects of the study are the old oak stands in Polissya and Forest Steppe, growing in conditions of fresh sugrud and fresh grud. The aim of the study is to identify climatic factors affecting the oak (Quercus robur L.) radial growth in Polissya and the Forest-Steppe and to compare its response to climate change in both natural areas. Standard dendrochronological methods were used to generate the Quercus Robur L. tree‐ring chronologies and to evaluate the relationship of the chronology with the meteorological records. In comparison, the influence of climate on the European oak radial growth in 1960 - 1988 and 1989 - 2013 for both natural areas there was in temperature increase in the second period compared with the first by 17-19%. In the second period in comparison with the first period temperatures increased most rapidly in Winter (by 34-41%) and early spring almost by four times in Polissya iand Forest Steppe. Precipitation trends are similar for both natural zones - there was an increase in the annual amount of precipitation, but during the growing season they fell less in April-June of the Polissya zone - by 11%, and for the forest-steppe zone - during July-August and the winter period - by 10% less. The reference years of maximum (1891, 1902, 1924, 1931, 1957, 1971, 1987) and minimum (1895, 1906, 1918, 1922, 1929, 1936, 1950, 1976, 1992, 2000, 2005) radial growth of European oak for Polissya were revealed as well as positive signature years for and Forest-Steppe (1971, 1978, 1987) and negative reference years (1918, 1922, 1929, 1936, 1950, 1976, 1992, 2000, 2005). Negative reference years are characterized by a deficit of precipitation, droughts of the growing season, cold or too warm winter and early spring periods, and positive - favorable for tree growth ratio of temperature and moisture. For the first period (1960-1988) the positive influence of winter and early spring temperatures on the radial growth of oak in Polissya and in the Forest-Steppe was revealed. In the second period (1989 - 2013) the opposite scenario took place - a significant increase in winter and early spring temperatures growth. In the second period, oak stands in Polissya suffered more from warm winters than plantations in the Forest-Steppe. The negative impact of vegetation droughts on growth increased in the second period for both plantations. During the second period, precipitation significantly lost its positive effect on plantations growth both in the Polissya and Forest-Steppe. The hypothesis of increasing the sensitivity of the European oak radial growth response on climate change in Polissya and Forest-Steppe has been confirmed.
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