Dendrochronological Investigation of Radial Growth of Quercus infectoria in Kermanshah Oak Forests

Many characteristics of the trees including annual ring width are affected by climate variations. This research investigates the effect of temperature and precipitation on tree rings of Quercus infectoria. Twenty two healthy and thick trees were selected from oak forests located in the region near Javanrood in Kermanshah with geographical coordinations of 34° 47' 30"N and 46° 20' 6E". Samples were taken by increment borers. After preparing the sample surfaces, rings width were measured by binocular and LINTAB measurement table and TSAP software. Cross dating was carried out using TSAP software. Data of six trees were excluded because of low cross-dating indexes. ARSTAN software was used to develop the ring-width chronology. Data of temperature and precipitation were collected from the nearest meteorological station and their effect on tree-rings were investigated. The results showed that temperature had a negative effect whereas precipitation had a positive effect on rings width because of warm and dry condition of the region. Rings width was positively and significantly correlated with precipitation in March and May while temperature affected the rings width negatively and significantly in January, February and June. The effect of precipitation on tree growth was more significant than temperature.