Electing drought-resistant pinus pinea L. (stone pine) using dendroclimatology

Abstract

The purpose of this study is to determine the exceptional dry years of Pinus pinea L. (stone pine) by using dendroclimatology, and Selection drought-resistant trees depending on the differentiation in the width of the annual growth rings of exceptional dry years and adopting them as seed mothers. Method. Sixteen samples were taken from four different sites (A, B, C, and D) (four samples per site). Cores were extracted from 10 trees per sample and the transverse surfaces of all cores were smoothed to expose the tree rings. Cores were then scanned and annual ring widths were measured from 2019 to 2005 using ScopeImage Plus software. By using the Moving Average as a smoothing technique, the exceptional years of the time series for the width of the annual growth rings for each sample were determined. More specifically, results show that 2008 and 2014 are negatively exceptional years across all the sites. Furthermore, the correlation coefficients between the ring-widths, the annual precipitation, and temperature for each site show that the annual precipitation is the determinant of the occurrence of exceptional years and that 2008 and 2014 are the dry years in our chosen sites. When comparing the ring widths of the dry years, it was noticed that tress (Aa4, Ab6, Ac9, Ad2) in the site A, (Ba10, Bb1, Bc3, Bd1) in the site B, (Ca9, Cb5, Cc8, Cd1) in the site C and (Da1, Db3, Dc7, Dd3) in the site D are superior and have wide rings. Scientific novels. According to this study, these trees can be selected as drought-resistant and adopted as seeds mothers which can be used in the propagation of Pinus pinea.