The Climatic Response of Tree Ring Width Components of Ash (Fraxinus excelsior L.) and Common Oak (Quercus robur L.) from Eastern Europe

Abstract

This paper aims to develop the first differentiated (earlywood—EW, latewood—LW, and total ring width—RW) dendrochronological series for ash (Fraxinus excelsior L.) and oak (Quercus robur L.) trees from the Republic of Moldova, and to analyze their climatic response and their spatio-temporal stability. For this, 18 ash and 26 oak trees were cored from the Dobrușa protected area, Republic of Moldova, Eastern Europe, and new EW, LW, and RW chronologies were developed for ash and oak covering the last century. The obtained results showed that the RW and LW have a similar climatic response for both species, while EW is capturing interannual climate variations and has a different reaction. The analyses performed with monthly climatic data revealed a significant and negative correlation with the mean air temperature and a significant and positive correlation with precipitation and the Standardized Precipitation-Evapotranspiration Index (SPEI) for both ash and oak. The temperature during the vegetation period has a strong influence on all tree-ring components of ash, while for oak the strong correlation was found only for LW. The positive and significant correlation between LW and RW with precipitation for both species, suggests that ash and oak are sensitive to the hydrological component and the precipitation is the main tree growth-limiting factor. Despite the significant correlation with precipitation and temperature for the whole analyzed period, the 25-year moving correlation analyses show that they are not stable in time and can switch from positive to negative or vice versa, while the correlation with SPEI3 drought index, which is a integration of both climatic parameters, is stable in time. By employing the stability map analysis, we show that oak and ash tree ring components, from the eastern part of the Republic of Moldova, have a stable and significant correlation with SPEI3 and scPDSI drought indices from February (January) until September, over the eastern part of Europe.

A Tree Ring Measurement Method Based on Error Correction in Digital Image of Stem Analysis Disk

“…In Equation ( 6), n is the number of independent variables, is the true value, is the estimated value, and p is the number of independent variables. In Equation (6), n is the number of independent variables, y i is the true value,ŷ i is the estimated value, and p is the number of independent variables.…”

“…Stem analysis is of great significance for the monitoring of forest tree growth state [1]. Annual rings are the archives of trees used to study forest yield, basal area increment, forest patch dynamics, insect outbreak, and tree growth response to climate change [2][3][4][5][6]. Tree ring width measurement mainly includes the microscope method [7], the image method [8], the ray method [9], and the tree ring analysis system based on a combination of the microscope and image methods [10].…”

Реакція радіального приросту Quercus robur L. на зміни клімату в Поліссі та Лісостепу

“…Засухи навесні і влітку у поєднанні з високою температурою повітря призводять до формування вузьких кілець. Висока чутливість дуба до тривалих дій посухи, що безпосередньо впливають на ріст дерев, може використовуватися як ознака раннього попередження необхідності прийняття належних планів та стратегій управління лісами, які мають вирішальне значення для підвищення їхньої стійкості до майбутніх екстремальних подій (Roibu et al, 2020).…”

“…Для збереження насаджень за участю Quercus robur потрібні знання не тільки про їхній сучасний стан, але й про зміни за більш тривалий період. З огляду на це дедалі більшого значення набувають дендрохронологічні дослідження дуба звичайного (Melekhov, 1979;Williams, 1992;Speer, 2010;Cedro, 2007;Roibu et al, 2020;Cook, 1990).…”

Species-Specific Effects of Groundwater Level Alteration on Climate Sensitivity of Floodplain Trees

“…These studies also show a temperature signal, but it is more unstable, and the temperature response can be either negative or positive, depending on the site [16,33]. There are fewer studies of ash in European floodplains, and these predominantly focus on Fraxinus excelsior L. They show a high sensitivity to drought-related indices [34][35][36]. While Quercus robur grows at diverse site conditions, with an associated better adaptation to lowering water availability, Fraxinus angustifolia grows predominantly at sites with easily available water [37].…”