Retrospective assessment on Scots pine stands situated far and near Chernobyl fallout areas

Abstract

The high radiosensitivity of woody plants and the large forest areas polluted by Chernobyl fallout demand assessment of radiation effect on the forest ecosystems components. This research aims to study the state of Scots pine (Pinus sylvestris L.) stands located in the far and near areas contaminated by Chernobyl fallout, and to assess the current dose loads on the structural elements of the trees 30 years after the Chernobyl Nuclear Power Plant (CNPP) accident. The study was conducted in radioactively contaminated Scots pine stands, which are the near and far areas,in the Chernobyl fallout areas. The experimental plots were established during the period from 1991 to 2006 inside Scots pine stands from the II–IV age classes. The retrospective assessment of dose loads of the Scots pine was conducted according to the data obtained on 13 experimental plots located in the far area of the Chernobyl fallout through the software RESRAD-BIOTA 1.5 (11/18/2009). The condition of pine stands in the near areas has significantly worsened since the accident, compared to their condition before the accident. The changes in the state of the pine stands after the accident were characterized by their strong weakening. Ambiguous trends were also observed in the stability of stands depending on the type of forest and land relief. In 1986, the radionuclide 134Cs accounted for 25 % of the total amount of soil pollution by mixture (134Сs + 137Сs) in pine stands. However, in 1995, this amount decreased to 2.5 %. The state of the Scots pine stands after the accident were characterized by their strong weakening.