The Impact of Altitude on Climatic Parameters and the Characteristics of Forest Soils

Document Type : Research Paper


Department of Soil Science, Faculty of Agriculture, University of Zanjan, Zanjan, Iran


In this study, the effect of altitude on climate and soil properties of forest soils in the Talesh region of Gilan province, Iran was investigated. Soil samples were collected from four altitudinal classes (500-1000, 1000-1500, 1500-2000, and 2000-2500 m) and soil properties and nutrient contents were measured. Climate data were also collected from the TerraClimate database. The results showed that with increasing altitude, precipitation increased and temperature decreased. The rate of increase in precipitation was 536.50 mm and the rate of decrease in temperature was 7.40 °C per 1000 m increase in altitude. Evapotranspiration also decreased with decreasing temperature at higher altitudes. Soils at higher altitudes had higher organic matter, total nitrogen, soil aggregate stability, and water holding capacity. However, available nutrients (K, S, P) were lower due to greater leaching and slower decomposition of organic matter at higher altitudes. The decrease in these nutrients was 15.18, 7.89, and 42.14%, respectively. Soil pH, bulk density, and salinity also decreased with increasing altitude. The findings of this study showed that although soils at higher altitudes have higher organic carbon content and water holding capacity, which can improve soil quality and forest ecosystem performance, they have lower available nutrients due to greater leaching. This can lead to nutrient depletion and acidification of these soils. Therefore, proper management of these soils, such as fertilization and liming, is essential to maintain ecosystem health.


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