C04_P04

A growth rate variability of Ziziphus spina christi in North-central Oman determined by a series of radiocarbon measurements

Kitagawa H¹, Miki T², Kuronuma T³, Kondo Y³

¹Institute for Space‐Earth Environmental Research, Nagoya University, Nagoya, Japan, ²The University Museum, The University of Tokyo, Tokyo, Japan, ³Research Institute for Humanity and Nature, Kyoto, Japan

Ziziphus spina christi, known as Christ's Thorn Jujube, is a thermophilic tree grown in arid and semi-arid areas. It was already in use as a medical plant in Ancient Egypt and is currently used for multipurpose such as food, fodder, fodder fuel, drink, timber, and medicine. The ecological and chemical properties of the multipurpose plant have been intensively studied, but there is a missing knowledge about the growth rate of Ziziphus spin christi that the annual ring is unclear. We conducted a series of radiocarbon measurements of a 23 cm-long core of Ziziphus spina christi collected from Wādī Tanūf, Northcentral Oman. The secular change of growth rate was estimated by a wiggle matching method incorporating dynamic time wrapping (DTW) algorism for measuring similarity between two temporal sequences: radiocarbon calibration (IntCal20) and dataset from the Ziziphus spina christi（this study). Based on the growth rate estimated, we discussed the climatic influence on the growth rate. Our result supports the hypothesis that an increase in winter temperature may be beneficial for growth and the recent widespread of Ziziphus spina christi in the eastern Mediterranean is presumably related to a gradual increase in winter temperatures.