Ability of different tree species in the reduction of mechanical stress of wind in the arid regions

 One of unfavorable factors in agriculture in each geographical region is exquisite winds which with increasing evaporation and transpiration amount led to decrease in water use efficiency. Therefore, it is necessary to control with the most adaptable Plants as the windbreak. This study was conducted to ascertain the most adaptation of windbreak in Damghan arid region. The climatic information was collected and climatic classification was done according to Demarton Method. Soil samples were collected from each observation plot in two different layers of 0–20, 20–40 cm from different soil cores. Finve tree species including Pinus eldarica, Thuja orientalis, Cupressus arizunica, C. sempervirnce and C. sempervirens var horisontalis were planted as dense windbreak model. The obtained results showed thatPinus eldarica decreased 403.22 kgm/s of wind power in first row, but Thuja orientalis, Cupressus arizunica, C. sempervirnce and C. sempervirens var. horisontalis decreased 137, 287.09, 112.25 and 229 kgm/s respectively. The most resistant species to chilly conditions were Pinus eldarica, Thuja orientalis, Cupressus arizunica, C. sempervirnce and C. sempervirens var. horisontalis respectively. On the basis of our results C. sempervirens var. horisontalis species is not recommended as windbreak due to sensitivity to chilly condition.