Dendrochronological studies of Juniperus communis dying out population in the "Jalowce" reserve (Pomerania)

The aim of undertaken research was recognition the reasons of dying out the common juniper Juniperus communis L. ssp. communis population in the forest nature reserve “Jałowce” (Pomerania). Applied methods of dendrochronological analysis let to determine the age of juniper-stand in the reserve and describe the influence of climatic conditions on its growth. Obtained results testify to Juniperus communis chronology with signature WIE collected from 17 individual sequences which numbered 102 tree ring width and represented a time span 1903 to 2004. Such results described the juniper-stand in the reserve as ageing population with the oldest specimen at age 98 years. However, the last several years were characterised by the lack of strong growth depressions typical for earlier time periods with tree ring width ranged 0.7–1.0 mm (themean annual tree ring width amounted to 0.85 mm), but the visible symptoms of degeneration and dying out of protected common juniper population intensified probably because of its age.