Pointer years in the growth of beech trees of the NP "Đerdap" area

Abstract

This paper defines pointer years and years with distinctive tree rings in the growth of beech in 3 sites (ecological units-EU) of the area of Đerdap, in order to observe the reactions of trees to the effects of various factors of growth. The pointer years were determined by the Schweingruber (1983) methodology. The years with distintive tree rings were defined as the years of beech growth with very pronounced distinctive growth rings (annual ring width at least ± 2 standard deviations higher or lower than the arithmetic mean) and pronounced typical growth rings (annual ring width at least ± 1.5 standard deviation higher or lower than the arithmetic mean). The common pointer years for the growth of beech in the site conditions of all three ecological units are 1977 and 1988 (negative pointer years). A particular pointer year is 1988, when in more than 90% of trees under the analyzed environmental conditions the marked reduction of tree rings width of the trees (EUB) or very pronounced reduction in the width of tree rings (EUA and ESV) were observed. [Projekat Ministarstva nauke Republike Srbije, br. 43007: Istraživanje klimatskih promena na životnu sredinu: praćenje uticaja, adaptacija i ublažavanje]

Keywords

• tree growth
• radial increment
• beech
• pointer years and tree rings
• Đerdap