The effect of land types and consequently land use on soil organic carbon content – case study: Damavand region of Iran

Abstract

Organic carbon is an important component of soil that influences soil fertility, biological activity, food security, and climate change. One of the important issues in soil science is the establishment of empirical relationships between different soil properties. The objectives of this research were to investigate the influence of different factors on soil organic carbon, such as total nitrogen, clay content, calcium carbonate equivalent and pH, for soils from various geomorphologic settings in the Damavand Region in Northwest Tehran, Iran. Regression models were developed for prediction of the organic carbon content of soils characteristics in this region. Lower SOC concentrations were measured for plateau soils (~4.92 g kg-1), associated with lower plant biomass and reduced temperatures at higher elevations. In contrast, soils from River Alluvial Plain regions, which are currently utilized for gardening, had the highest organic carbon content (~22.05 g kg-1). For all landform types (i.e., alluvial fan (irrigated farming lands), plateau (Rangeland), and River Alluvial Plain soils (garden)), SOC had positive and significant relationship with total nitrogen (r = 0.962, p < 0.01). Simple linear regression, multiple linear regression, and nonlinear regression models were also developed for describing the relationship between SOC and landforms physical and chemical characteristics.