The suitability of height and radial increment variation in Pinus sylvestris (L.) for expressing environmental signals

Abstract

The relationship between radial and height increment of Pinus sylvestris (L.), as well as their dependence on climatic variables, was investigated using material sampled in southern Finland. The radial and height increment indices exhibited similar annual and periodical variation. However, changes in the height increment series occurred later than those in the radial increment series, i.e. the height increment of the current year was more strongly correlated with the radial increment of the preceding year. Cross-correlation analysis between climatic variables and index chronologies showed that radial increment was mainly determined by the summer temperatures of the current and two preceding years. On the other hand, height increment was most strongly correlated with the temperature of the preceding year. It was concluded that, due to the similar type of variation, both height and radial increment can be used in the construction of index chronologies and in deriving environmental signals from them. However, the use of height increment has no major advantages over radial increment. Due to difficulties in defining annual height increments and frequent terminal damage, more trees are needed to obtain reliable height increment chronology.