Wood types and environment of the Tashkurgan region, Xinjiang, at 2500 cal yr BP, based on a record from the Ji'erzankale Necropolis

Abstract

The Ji'erzankale Necropolis, dating back to 2500calyr BP, is located in the Tashkurgan, Xinjiang Uyghur Autonomous Region of China. Abundant wooden objects were unearthed in 2013 and 2014, including plates, fire altars, hearth boards, hand drills, wooden sticks, arrow shafts, bowls, two pieces of konghou (musical instrument) and a harp, among other things. Species identification of 70 wooden objects from 25 tombs indicates that they were crafted from at least seven different trees, namely Juniperus sp. (4), Populus sp. (15), Betula sp. (28), Salix sp. (8), Lonicera sp. (8), Elaeagnus angustifolia (1), Fraxinus syriaca (2), and four unidentified types. Based on the ecological habitats of the different species, we inferred that woodland dominated by Betula, Populus and Salix, with some associated Lonicera and Elaeagnus angustifolia, developed on the floodplain of the Tashkurgan River, with Juniperus boscage on the shady slopes of the local mountains. This vegetation community suggests that an arid/semi-arid oasis environment was extant at that time. Comparing this result with the shrubs found in today's floodplain and montane desert environment, our findings indicate that the climate of the Tashkurgan River valley was relatively humid around 2500years ago. This probably resulted from an increase in precipitation transported to the region by the mid-latitude westerlies.