Investigation and consideration of forest tree reaction to climate and environmental changes (Case study: Lavizan forest park)

This study explores the influence of climate and environmental changes on 5 tree species (Cupressus arizonica، Robinia pseudoacacia)، Fraxinus rotundifolia، pinus eldarica and Celtis australis) in Lavizan plantation forest park، which is located in northern part of Tehran. Although، recreation parks are under irrigation، but still trees and vegetation cover are influenced by environmental and climate factors. In this research، dendrochronology study method have been used to identify different reaction of these five tree species to environmental and climate changes. Plants، especially، trees are sensitive to their environmental changes، and tree-ring width is one of the reliable proxies of ambient environmental conditions. Climate and environmental changes affect natural ecosystems as well as planted forests. This study has been conducted in 5 study plots in the park and instrumental data were derived from nearest meteorological station (Shomal e Tehran station) from 1988-2008. Correlation analysis was used (with SPSS Statistics Package and Excel) to explore relationship between climate and measured tree-ring widths. All the species show obvious decrease in tree ring width، in result of increasing temperature in the last 20 years. Substantially، environmental parameters like soil characteristics، gradient، slope direction and air pollution، affect the growth elements in all species.