Research in: Agricultural & Veterinary Sciences

The study aims to investigate the composition of absorbed bases and the changes occurring in the modern period in the mountain-forest soils of the Lankaran-Astara region. The article shows that under conditions of complex relief, humid subtropical climate and diverse forest formations, calcium (Ca²⁺) absolutely dominates (70-85%) in the adsorption complex of mountain-forest brown, chestnut-brown and gray-brown soils formed in the region, while magnesium (Mg²⁺), potassium (K⁺) and sodium (Na⁺) are present in smaller amounts. Regularities in the variation of the amount of absorbed bases with elevation above sea level have been identified: this indicator reaches its maximum in the lower mountain belt (400-800 m) and decreases toward higher belts. It has been determined that soils formed under ironwood forests are richer in absorbed bases compared to those under other forest types. The most important result of the study is that anthropogenic impacts (deforestation and intensive use of pastures) have led to a 15-25% decrease in the content of absorbed bases, particularly calcium and potassium and to soil acidification. The dynamics of these indicators over the last 40-50 years have been analyzed and scientifically grounded recommendations have been proposed to prevent soil degradation. The results of the study are of practical significance for the monitoring, protection and sustainable management of the region’s soil resources.