A retrospective, dual‐isotope approach reveals individual predispositions to winter‐drought induced tree dieback in the southernmost distribution limit of Scots pine

• DOI: 10.1111/pce.12072
• Publication Date: 2013-01-24T14:47:57Z
• Authors: JORDI VOLTAS; JESÚS JULIO CAMARERO; DAVID CARULLA; MÒNICA AGUILERA; ARACELI ORTIZ; JUAN PEDRO FERRIO
• Keywords: Scots pine; Tracheid

Abstract Winter‐drought induced forest diebacks in the low‐latitude margins of species' distribution ranges can provide new insights into mechanisms (carbon starvation, hydraulic failure) underlying contrasting tree reactions. We analysed a winter‐drought dieback at S cots pine's southern edge through dual‐isotope approach (Δ 13 C and δ 18 O tree‐ring cellulose). hypothesized that differential long‐term performance, mediated by interaction between CO 2 climate, determined fates individuals during dieback. Declining trees showed stronger coupling growth intrinsic water‐use efficiency ( WUEi ) than non‐declining was noticeable for 25 years prior to The rising stomatal control water losses with time declining trees, indicated negative Δ ‐ relationships, likely associated their native aptitude grow more take up (suggested larger tracheid lumen widths) and, therefore, exhibit greater cavitation risk. Freeze‐thaw episodes occurring winter 2001 unveiled such physiological differences triggering those vulnerable failure. Thus, tightly modulated responses warming indicating co‐occurring were differentially predisposed mortality. These different performances unconnected depletion stored carbohydrates.