Study of Some Growth Indicators of Quercus infectoria on the Side of Forest Roads (Case Study: Shoy Forest in Baneh City)

Extended Abstract Background: Road construction in the forest causes changes in the microclimatic and biological conditions of the roadsides, which lead to positive and negative consequences. Forest fragmentation leads to the creation of smaller habitats and changes in the ecological reactions of the forest, which are different at the distance from the road. These types of changes are called marginal effects. Marginal effects on tree growth indices are different and have been reported from positive to negative in many studies. A review of research records indicates that a few Iranian studies have investigated the marginal effects of forest roads on chlorophyll and carotenoid contents in leaves. Therefore, the current research intends to determine the consequences of forest roads in a part of Zagros forests by examining the marginal effects of forest roads. The contents of chlorophyll a, chlorophyll b, carotenoids, and the specific leaf area index (LAI), as well as the relative humidity of leaves and pollution caused by traffic and the amount of chlorophyll lost in leaves, were evaluated in this research. Methods: To evaluate the positive and negative consequences of road construction, specific LAI, leaf relative humidity, chlorophylls a, b, and carotenoids in leaves, and the amount of leaf pollution caused by dust were studied in the Shoy Forest of Baneh City, Kordestan province. The climate of the region is semi-humid based on the Dumarten climate factor. To carry out this research, a forest road with heavy traffic passing through these forests was selected and three transects were made at a distance of 100 m perpendicular to the road on both sides. At different distances from the road (0, 50, and 100 m), samples of oak (Quercus infectoria Olive.) leaves were collected along the transects. In each transect, the first sample plot of 10 × 10 m was adjacent to the road, and the second and third sample plots were located at distances of 30 and 50 m from the road, respectively. In each plot, leaf samples were collected from all parts of the crown, including infected, damaged, and healthy leaves. The contents of chlorophyll a and b and carotenoids were measured by the Avon method. Oak leaves were taken to the laboratory immediately after collection and their fresh weight was calculated using a digital scale (accuracy of 0.001 g). The surface of the leaves was measured by a leaf surface meter, and the humidity of the leaves was calculated through the weight rela