Multiple tree-ring parameters of Quercus brantii Lindel in SW Iran show a strong potential for intra-annual climate reconstruction

Abstract

Key message: Intra-annual tree-ring parameters of Quercus brantii contain high-resolution intra-annual climate signals which enable us to trace seasonal aspects of climate change and to reconstruct high-resolution climate data for the semi-arid region. Abstract: Environmental conditions affect growth potential and wood-anatomical features of tree species. Hence, valuable climate signals can be extracted from intra-annual tree-ring features. In this study, we evaluated the potential of intra-annual wood parameters of Quercus brantii Lindel growing in the semi-arid southern Zagros Mountains, Iran. We analyzed earlywood width (EWW), latewood width (LWW), total ring-width (TRW), and several vessel features of the oak species. Standard chronologies have been developed for ring-width and vessel parameters using dendrochronological and quantitative wood-anatomical approaches. Correlations with local climate data showed that precipitation during the pre-growing and growing seasons had positive effects on EWW, LWW, TRW, and latewood vessel size. In contrast, earlywood vessel size showed positive correlations with precipitation in the active growing period (January–April). EWW, LWW, and TRW showed negative correlations with temperature during the pre-growing and growing seasons. Earlywood and latewood vessel features showed stronger negative correlations with mean monthly temperatures during the vessel formation period. Our results revealed that EWW, LWW, and earlywood and latewood anatomical variables of the trees contain valuable climatic signals complementing each other over different seasons. Despite the often low common signal strength of the anatomical variables shared between trees, they showed strong climate–growth relationships which can be useful for the reconstruction of seasonally resolved climate parameters in a multi-parameter tree-ring approach.