Dendrochronological studies of Juniperus polycarpos in alborz mountains (case study: Shahkuh of shahrood)

The objectives of research were to create tree ring chronology of juniper trees and investigation on the relationship between the growth rate of the tree and the climate. Juniper trees are naturally distributed in High Mountain with semi-arid and arctic climate condition of Iran. Samples were collected from 20 trees in Shah-Kouh Mountain with 54° 42´ 58˝ longitude and 36° 61´ 01˝ latitude coordinate. Increment core were prepared and analyzed. The time span for tree ring chronology was 271 year (1741-2012 AD). Tree ring chronology statistic for MS، EPS، SNR، were 5. 6، 0. 85، 0. 29 respectively. Correlation between tree ring index and climate data showed that mean temperature in the previous growing season is an important factor for growth of juniper trees. The result of this research can help the development of climate data and is useful for the creation of weather atlas.