Scots pine (Pinus sylvestris L.) radial growth in the vicinity of the nitrogen fertilizers plant "achema" in Lithuania

Results of Scots pine (Pines sylvestris L.) growth in the vicinity of long-term air pollution source of Jonava nitrogen fertilizers plant "Achema" are presented. The objective of investigation was the analysis of changes in annual radial increment of Scots pine forests growing in the zones of intensive (3-12 km) and moderate (13-24 km) pollution during different periods (fertilization, depression and recovery) of tree reaction to air pollution. It was ascertained that during the fertilization period a small amount of nitrogen emissions affected tree growth positively: annual radial increment in both the zones of pollution was similar to the control forests or higher. Negative effect of pollutants on pine forests started in 1974-1979. The greatest damages to forests were caused in 1979-1983, when the amounts of emissions with prevailing sulphur dioxide were the highest (34-40 thou. tons annually). During the depression period annual radial increment of pine forests growing in the zone of intensive pollution comprised only 60-65%, compared to the control pine forests. The most severely damaged 60-year-old pine stands lost 2.66 m(3)/ha of wood per year on the average. In 1986-1988 changes in pine annual radial increment stabilized at the level of 1980-1982, while in 1990-2003 a tendency of pine forests recovery and increasing radial increment is observedGamtos mokslų fakultetasVytauto Didžiojo universiteta