Оценка устойчивости аридных почв юга европейской части России к загрязнению кадмием по биологическим показателям

Arid soils perform important ecological functions, primarily maintaining biodiversity and sustainability of the biosphere. Cadmium is among the priority pollutants for arid soils. The arid soils of the South of the European part of Russia differ in their resistance to cadmium pollution and form the following sequence (the soils are arranged in the descending order of their resistance): ordinary chernozems (haplic chernozem) ≥ dark brown (haplic kastanozems) ≥ chestnut (haplic kastanozems) ≥ light chestnut (haplic kastanozems)> brown semi-desert (haplic calcisols)> sandy (calcaric arenosols). The heavier the particle size and the higher the organic matter content in studied soils, the more bound and less toxic the metals are. Also, regional maximum permissible concentrations (rMPC) of cadmium in arid soils of the south of the European part of Russia were suggested basing on the violation of their ecosystem functions. Regional MPC of cadmium for ordinary chernozem (haplic chernozem) and dark chestnut soils (haplic kastanozems) is 3,0 mg/kg of soil, 2,4 mg/kg for chestnut (kastanozems haplic), 1,9 mg/kg for light chestnut (haplic kastanozems), 1,6 mg/kg for brown semi-desert (haplic calcisols), and 1,1 mg/kg for sandy brown semi-desert (calcaric arenosols). The developed rMPC can be used to standardize cadmium content in arid soils of other regions of the world. Also, prognostic maps of the degree of deterioration of the biological state of arid soils under different levels of cadmium pollution have been compiled for southern Russia.