Ecological and Geochemical Characteristics of the Content of Heavy Metals in Soils under Forest Ecosystems of the Karadag Natural Reserve

As part of an ecological and geochemical study of soils under plantings of Crimean pine (Pinus pallasiana), distributed within the boundaries of the Karadag Nature Reserve, the main qualitative and quantitative characteristics of the content of heavy metals (Ti, Mn, Cr, Ni, Cu, Zn, Rb, Sr, Zr) and metalloids (As) were established. According to the results of field determination, the soils are classified as dark-humus residual carbonate carbolithozems on limestone eluvium (dense limestone from a depth of 14-24 cm). The analyzed soils are high-carbonate (pH=8.0-8.1), the mechanical composition is coarse-silty-heavy loamy. The main mineralogical composition is represented by calcite, quartz, and various hydromicas. The quantitative content of the elements under consideration is within the existing MPC/APC standards, and correlates with clarke values for soils of the world (according to A.P. Vinogradov), which predetermines a low level of total pollution of the protected area. The exceptions are Ni (Kk=1.0-1.1), As (Kk=1.3) and Rb (Kk=101.7-103.3) which are characterized by accumulation throughout the profile. The Rb/Sr ratio, which is equal on average to 0.709±0.084 for the AU horizon and 0.759±0.081 for the Cca horizon, indicates a long and continuous time of soil formation. The location of the study area in a protected area with the minimum possible anthropogenic influence allows us to qualitatively assess the ecological state for the content of heavy metals in soils as extremely favorable.