This study aims at understanding the impacts of climate factors on the annual growth variations of oriental beech (Fagus orientalis Lipsky) at the Kheyrud Forest Research Station located in the Caspian forests of northern Iran. To this end, 18 disc samples were randomly taken from altitudes of 1038 to 1152 m above sea level. Tree rings were measured using TSAP-win software and a LINTABII machine. Since false and missing rings are typical in beech trees, skeleton plots were created to enhance crossdating accuracy. Chronologies were observed for a total of 15 samples. Meteorological data for rainfall and air temperature were recorded at the Nowshahr Meteorological Station, located near the study sites. Results showed a significant correlation between mean annual air temperature and radial growth (R D 0.54). Within the growing season, August temperatures reveal a significant correlation with tree ring (R D 0.41) while the highest association was observed in the previous December (R D 0.44) and the least association was found in February (R D 0.31). Excluding March (R D 0.33), there appeared to be no significant correlation between precipitation accumulated during and prior to the growing season and tree ring. In addition to oriental beech, there are many other species important to this region that may be sensitive to increasing temperatures.

Understanding forest growth and resilience under global climate change is crucial for forest management, to maintain wood supply for future. In this research, I focused on the response and resilience of subalpine fir (Abies lasiocarpa (Hook.) Nut)) growth to climate variables and severe drought events at five stands located along northern slopes of the Rockies in northern BC, Canada.Results revealed that temperature (especially summer and previous fall) was the most important climate factor controlling growth of subalpine fir trees at study sites. The lower the latitude, the more summer temperature negatively effected tree growth. Also, results showed that subalpine fir trees were resilient to very dry conditions at study sites, when considering the growth recovery period to drought was between 1 to 2 years. The lower the latitude, the faster the trees recovered from drought. However, subalpine fir trees located at higher latitudes were more resistant to the effects of drought.