LONG-TERM DAMAGE ON SCOTS PINE CAUSED BY GREMMENIELLA-ABIENTINA NEAR A NICKEL SMELTER IN THE KOLA-PENINSULA

The history of damage caused by Gremmeniella abietina on 10 Scots-pine trees (Pinus sylvestris) was studied near a nickel smelter in Tsuna, Russia. The most severely damaged area was located alongside a river. According to the results of branch analysis, the first sign of G. abie tina infection occurred in 1937. During the following 4 decades, annua l signs were few and they occurred at random. Most of the damage had a ppeared during the 1980s and the early 1990s. Ln terms of cankers, the peak occurred in the mid-1980s, and in terms of scars and leader chan ges, the peak was in the late 1980s and early 1990s. Branch mortality and secondary Tomicus spp. attacks increased in the late 1980s and wer e as their highest level in the early 1990s. The high number of mature G. abietina pycnidia on shoots formed in the years 1989-1991 suggests that the epidemic will continue in the near future.