Patterns of annual increment, structure and formation of tree ring under ionizing radiation were investigated in the zone affected by the Chernobyl Power Station disaster.
Analysis of extensive experimental data set (annual increment was measured more than 2000 cores) revealed a specific response of long-living plants like Pinus sylvestris L, Picea excelsa Link., Betula pendula Roth, and Alnus glutinosa L. to radiation, which manifests itself in changes of the annual ring growth dynamics. Trees were found to experience drastic suppression of annual increment at the year of the disaster followed by two years of intensified increment. The dependence] most explicit in silver birch and Norway spruce. On experimental grounds the procedure for biological dosimetry in forest biogeosystems was worked out: with a high degree of reliability, the procedure makes it possible to evaluate retrospectively the dose absorbed by forest ecosystems after nuclear disasters. The results of practical implementation of the proposed biological dosimetry procedure in a 10-km zone around the Chernobyl Power station in 1988–2000 are discussed. Application of the procedure to investigate the Tri Mail Isld Power Station case (USA) in 1979 is presented.