Investigation on the forest roads right-of-way based on earthworking limit, hillside gradient and vegetative characteristics of edge stands (case study in Lat Talar forest - watershed of Tejen river)

According to forest ecosystem conditions in Hyrcanian forests, the fixed numbers can not be useful for determining forest roads right-of-way. Also, these numbers are frequently ignored by the executives and road constructors in order to preserve valuable trees and avoid cutting these trees on sensitive points such as cut slopes and fill slopes. In some cases that roads right-of-way is considered based on standard numbers, the vegetative characteristics of edge stands is determinant of real forest roads right-of-way. In this study the status of real right-of-way was evaluated based on earth working limit, vegetative characteristics of edge stands and different slope classes of hillside in Lat Talar forests. Results showed that the forest roads right-of-way increased with raising hillside gradient (P<0.05). The mean width of real right-of-way in type A (Fageto-carpinetum with 155 stem per hectare and crown cover 75 percent) and B (Fageto-carpinetum with 175 stem per hectare and crown cover 85 percent) were 15.10 and 14.21, respectively. The most overlapped area between real right-of-way and fill slope of roads was observed in slope classes 30-40 and 40-50 percent in both types and the lowest overlapped area were seen in slope classes 50-60 and 60-70 percent. Finally, the optimum right-of-way of forest roads was separately determined for cut and fill slope in steep slopes of Hyrcanian forests using chart models. This method decreases the rate of tree felling and increases the safety and permanency of forest roads.