The effect of climate on the radial growth of Oriental Beech in the Southern limit of its distribution area

Abstract

This study was carried out to construct a site chronology of oriental beech in Topaktas site of the Amanos Mountains, one of the most southerly populations of oriental beech, and to investigate the relationships between tree-ring width and some climate variables such as the monthly maximum, minimum and mean temperature and monthly total precipitation. The study area was located in Topaktas Plateau, Dortyol, Hatay, where isolated natural populations, known as the most southerly populations of the species, exist. The average slope was 35%, the aspect was north-west, and the altitude ranged from 1300 to 1500 meter (m). 33 samples are collected by using increment borers and taken from 17 oriental beech trees in the study site, and 53-year-long treering chronology were built for the period of 1961-2013. Pearson correlation coefficients were used to investigate relationships between radial growth and climate. The radial growth of oriental beech in the site was found to be sensitive to climate with mean sensitivity value of 0.20. The results showed that high precipitation in June leads to produce wider rings (r=0.39, p<0.01), while maximum temperature in the same month has a negative significant effect on radial growth (r=-0.32, p<0.05). On the other hand, high precipitation in February and March decrease ring width of oriental beach (r=-0.30, p<0.05).