Title : Differences in climate-tree ring width relationship of Scots pine from various generations dunes in the southtern Baltic coast
The aim of the study was to determine the impact of climatic conditions and diverse habitat (different age-old dunes on the shores of the southern Baltic Sea, different duration and degree of soil-forming processes) on the tree-ring width of Scots pine (Pinus sylvestris L.). The samples were taken in three generations of dunes: brown dunes (BD) about 2000-5000 years old BP, yellow dunes (YD) 200-2000 years old BP and white dunes (WD) that were formed about 200-300 years ago. Soil outcrop were made on the examined plots, soils were described and samples were taken for soil science analyzes. A total of 66 trees were sampled, and three local chronologies were compiled on the basis of measurements of tree-ring width: BD - 93 years (1926-2018), 92 years YD (1927-2018) and WD - 139 years (1880 -2018). The age of the trees in the white dunes (WD) indicates that this is the first generation of forest in these dunes. The measured and indexed chronologies were the basis for further dendroclimatological analyzes. The growth rate (both the average tree-ring width and cumulative radial growth) is highest in brown dunes, and lowest in white dunes. Also, the growth-climate relations show differentiation depending on the age of the dunes: trees growing on the oldest dunes (BD) show typical growth-climate relations for this species, i.e. tree-ring width is most strongly influenced by the thermal and pluvial conditions of the end of winter and the beginning of spring (warm and rainy winter, a quick and warm spring causes rise to wide tree-rings). An additional factor influencing the growth of trees is rainfall in the summer months. In the younger dunes (YD and WD), summer rainfall is becoming more and more important, and the impact of thermals is decreasing. The diversified growth-climate relationship can be explained by the different degree of advancement of soil-forming processes, especially the accumulation of humus and the podsolization process.