Abstract

This study was conducted in Al- Jabel AL- Akhdar region, east Libya to identify the impact of environmental variations on wood formation of Pinus halepensis and Juniperus phoenicea trees growing at different altitudes. The study manifested the effect variation of the environmental factor on growth rings at the three altitudes and this may ascribed to the condition at each altitude, since the multiple regressions (R²) value obtained were significant forpine and juniper trees under the conditions of each altitude. However, the highest (R²) was found at the altitude of 248m for Pine tree. Also, (R²) was increased with the altitude for Juniper tree at the altitude of 413 and 780m, respectively. Furthermore, the results of this study allow to know precise information about the climate conditions on the previous early stages for the tested trees, which clearly reflected in tree ring patterns in the region of Al- Jabel Al- Akhdar. These comprehensive data described in this study was to point out that the climate factors (which differ from altitude level to another) have great influences on tree ring width.