Relationship between some soil chemical characteristics and few tree types of Zagros forests: case study of Marivan

The purpose of the study was to investigate some of the soil chemical characteristics of few forest types of Zagros region of Iran at Marivan City of Kurdistan province. For this reason, map of the forest types was developed at first. The forest types were: Quercus brantii- Crataegus potnica, Quercus brantii- Acer monspessulanum, Quercus libani- Quercus brantii, and Quercus libani- Pistacia atlantica accompanied with Pyrus syriaca. In order to study the chemical characteristics, four soil profiles were dug in each forest type at same level of altitude and slope. Soil samples were taken from different depths of the profiles (0-25, 25-50, and 50-75 cm). The trial was conducted under the design of Randomized Complete Blocks with four replicates. The results showed that the amount of organic carbon of the first layer of the soil profiles in all forest types was greater than the other two layers, whereas Quercus brantii - Acer monspessulanum type had the lowest amount among the forest types. Furthermore, pH of the soil profile of this forest type was greater than the other forest types due to probably higher level of lime in its soil profile. There was not significant difference between the forest types in respect to amount of nitrogen, whereas the amount of phosphorus at the mentioned forest type was at the lowest level due to low amount of organic carbon. The amount of potassium at the all forest types decreased when the soil depth increased. Overall, the forest types differed significantly in respect to their soil chemical characteristics and the forest type in which there was greater level of organic carbon, they had more appropriate soil characteristics in comparison to the other forest types