Investigation on Climate Change Effects on Hyrcanian Forest Ecosystems (in Gilan Province) with Emphasize of Wood Dendrology Studies

Importance of global warming and its influence on natural resources, plants, animals and generally human life have been concerned from many years ago by scientists and policy makers. Climate change is accompanied With simultaneous changes of temperature, precipitation and CO2. Hence study precipitation changes pattern has to be carried out parallel with CO2 and temperature effect. Based on studies on annual growth ring during last 600 years, 20th century was the warmest period, but this condition was expetional in Syberia that 15th century summer was warmer than 20th century. Green house gases are known affecting on climate change. Green house gases absorb Infra-red and led to increasing temperature atmosphere, witch cause to change in physiological activities of plant. Study showed that temperatures vary paralled with amount of CO2 and there relation between annual precipitation and of annual rings of tree, temperature and CO2. In current research in Hyrcanian forest ecosystem seven (transect) profiles (3 in Guilan, 2 in Mazandaran and 2 in Golestan provinces) have been selected in watershed level for three study points each profile from low, medium and high elevation zone fron sea level height. At least three important forest tree species including beech, hornbeam and oak have been selected. Several samples, up to 15 (minimum three tree) have been selected as discets or increament cores (with increment borer) in each study point. Radius vector trees samples recorded data of tree ring width were analyzed and calculated for ANOVA, regression and correlation with Spss16 and Mtb 14 softwares. Results for example Guilan province showed significan change for beach growth in short period with 43 year climatology change climate after 1992. For longer period 250 years dry phenomenon with impact on radius vector tree were occurred, but in short time. Sensitivity of tree ring width including oriental beach suitable tools for measuring climate change impacts on Hyrcanian forest trees. The main goal of this research was considering effect of temperature, precipitation and humidity on annual growth rings of forest trees.