Dendroclimatological Analysis of Radial Growth of Old-Growth Oak (Quercus Robur L.) on the Oder River Floodbank in the City of Wrocław, South-Western Poland

The goal of this work was to study the temporal stability of the climate/growth relationship of 15 pedunculate oak trees in Wrocław, SW Poland. Furthermore, pointer years were defined and the span of their meteorological conditions was assessed. The tree-ring widths were measured with an accuracy of 0.01 mm using LINTABTM 6 and the TSAP-Win software. The site chronology covered 128 years from 1887 to 2014. The tree rings were on average 3.56 mm wide and ranged from 2.10 to 5.43 mm. Their variation was significantly influenced by temperature and precipitation. Tree-ring widths from 1965 to 2014 were most influenced (positively) by June precipitation in the year previous to the formation of the rings. From 1915 to 1964, the tree-ring widths were most strongly and negatively influenced by November precipitation recorded in the previous year. Ten pointer years were identified, three of which were positive and seven negative. Both in the group of positive pointer years (1917, 1966 and 1982) as well negative years (1923, 1951, 1953, 1960, 1981, 1989 and 2009), we were unable to determine variation patterns of temperature and precipitation. Research on the TRW series of pedunculate oaks on flood protection embankments should be continued to better understand the effect of climate conditions on annual tree growth.