Characteristics of the Pigment Complex of Betula pendula Roth. Leaves in Different Types of Pollution in the South Ural Region

The article presents the results of a study of the pigment complex of silver birch leaves growing under conditions of various types of industrial pollution in the South Ural Region. Those are Sterlitamak Industrial Centre (aerotechnogenic polymetallic pollution), Karabash Copper Smelting Plant (aerotechnogenic polymetallic pollution in combination with sulfur dioxide), Uchaly Mining and Processing Plant (polymetallic pollution in the conditions of overburden rock dumps of the copper-pyrite mining industry), Kumertau Brown Coal Mine (polymetallic pollution in the conditions of overburden rock dumps of the brown coal mine), Ufa Industrial Centre (aerotechnogenic petrochemical pollution). An imbalance in the pigment complex of birch leaves is shown for all the types of pollution studied, which is expressed in the lack of consistency between the adaptive responses of pigments and their ratios. It is not possible to clearly identify the overall adaptive response for the entire pigment complex in each industrial centre. With a certain degree of conventionality, it can be noted that in the case of polymetallic pollution in combination with sulfur dioxide, the pigment complex is characterized by a predominantly tolerant adaptive reaction, in the conditions of overburden rock dumps of the copper-pyrite mining industry – a stressful one, in the conditions of overburden rock dumps of the brown coal mining industry – a neutral one, and in the case of petrochemical and aerotechogenic polymetallic pollution, there is no predominant reaction. According to the degree of increasing imbalance in the pigment complex, the industrial centres form a series in an ascending order: Kumertau Brown Coal Mine – Uchaly Mining and Processing Plant – Karabash Copper Smelting Plant – Sterlitamak Industrial Centre – Ufa Industrial Centre. The ratio of chlorophyll a and b determines a stable balance between chlorophylls in all types of pollution, but highlights petrochemical pollution as a more significant stress factor. The ratio of chlorophyll a + b and carotenoids shows a lack of stability in all types of pollution and highlights aerotechnogenic polymetallic, petrochemical and polymetallic pollution in the conditions of copper-pyrite dumps as more significant stress factors. The development of recommendations for the use of birch for protective plantations should be based on a comprehensive assessment of its adaptive responses at various hierarchical levels. This will make possible the targeted use of birch in conditions where it is tolerant to pollution and has a high adaptive potential, and will exclude its use in plantations in stressful conditions where its adaptive capabilities are limited.