TY - JOUR A1 - Süßel, Florian A1 - Brüggemann, Wolfgang T1 - Properties of secondary xylem of mature oaks in southwest Germany formed after extreme drought stress in summer 2018 T2 - Trees, forests and people N2 - The effect of the extreme summer drought and heatwave 2018 in Central Europe on wood properties of oaks at four sandy valley river sites (Quercus robur L.) and one south-exposed schist slope (Qu. petraea (Matt.) Liebl.) in the middle Rhine and lower Main valley were studied and compared to well-watered trees from a riparian stand. While properties of the 2018 tree rings mostly resembled those of the previous (wet) year, significant decreases in Δ13C, wood density and ring width occurred in 2019 at most drought-prone sites. In the sandy sites, ring widths correlated with previous-year precipitation from June to August over a 20-year period. In organs formed in 2018, in general, decreasing Δ13C values were obtained in the order leaves, twigs, wood and acorns, with the values from acorns often resembling those from 2019-year rings. The observed changes indicated an increased intrinsic water use efficiency and lack of starch reserve formation during the unprecedented hot and dry summer 2018. Qu. petraea revealed quite different values from Qu. robur (lower Δ13C, wider and denser year rings), but qualitatively showed the same reaction to the drought in 2018, except for an enhanced formation of tyloses in recent-year tree rings. KW - Drought KW - Oaks KW - Tree rings KW - Tylosis KW - Wood properties KW - Xylem Y1 - 2021 UR - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/63071 UR - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-630715 SN - 2666-7193 N1 - This work was funded by the research funding programme “LOEWE - Landes-Offensive zur Entwicklung Wissenschaftlich-ökonomischer Exzellenz" of Hesse’s Ministry of Higher Education, Research, and Arts, by the Leibniz Association (Berlin) through the collaboration project “South Hesse Oak Project” between Senckenberg - Leibniz Institution for Biodiversity and Earth System Research and Goethe University Frankfurt and by the Association of Friends and Sponsors of the Johann Wolfgang Goethe-University, Frankfurt. VL - 5 IS - art. 100097 SP - 1 EP - 10 PB - Elsevier CY - Amsterdam ER -