Development of diagnostic scale for assessing the vital state of pine stands under technogenic pollution by emissions from a large aluminum smelter
O. V. KALUGINA1, L. V. AFANASYEVA2
1Siberian Institute of Plant Physiology and Biochemistry SB RAS, Irkutsk, Russia
2Institute of General and Experimental Biology SB RAS, Ulan-Ude, Russia
Keywords: diagnostic scale, Pinus sylvestris, vital status, antioxidant system, technogenic emissions, aluminum smelter
Abstract
In course of many years of research on assessing the state of pine forests polluted by emissions from the Bratsk aluminum smelter, a large array of data of different sizes has been accumulated, and when generalized and structured, two groups of representative indicators were identified. The first group includes indicators with a high degree of reliability characterizing a state of the assimilating phytomass and growth processes of polluted trees: percentage of green needles in the tree crown, mass of needles on the shoots, total content of chlorophyll in the needles of the shoot, ratio of protein and non-protein nitrogen in the needles, value of the ratio Fv / Fm . The second group included indicators reflecting the efficiency of the antioxidant system: content of low-molecular metabolites (proline, catechin, total glutathione digetogulonic acid), as well as the activity of peroxidase enzyme. Based on these parameters, integral indices were calculated. The regression dependences between the indices and a level of pollutant elements accumulation in needles were used to develop a scale for assessing the vital state of forest stands under conditions of technogenic pollution by emissions from a large aluminum smelter. Applying this scale, it is possible to identify changes at the earliest stages, when the external signs of tree weakening are not yet manifested or are minimally expressed. A schematic map has been compiled, reflecting the distribution of pine forests of varying degrees of oppression. It has been established that the maximum weakening in the state of forest stands (more than 70 %) is observed in local areas in the industrial zone of BrAZ, strong (within 50-69 %) is found in different directions from the smelter at a distance of up to 10 km, average (by 31-49 %) - typical for forest stands at a distance of up to 40 km, weak (by 11-30 %) - at a distance of 40-60, less often 80 km from BrA Z. In the rest of the surveyed area, changes in the vital state of pine stands are minimal, which makes it possible to characterize the stands as healthy (background).
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