Wood from the 4th − 7th century CE in Kuča Caves in Xinjiang, China: Past vegetation and preliminary wood utilization

Taitai’er Grottoes and Mazabha Grottoes are integral components of the Kuča Caves，and the date of the caves were from the 3^th to 9^th century CE. To investigate how monks utilized wood during this period and to analyze the climate and vegetation characteristics of that era, we conducted a systematic identification of 58 wood samples found in fireplaces, wooden architectural components, and woodware within the two caves using dendrological identification methods. Five species of wood were identified: Populus sp. (poplar) , Salix sp. (willow) , Hippophae sp. (sea-buckthorn) ,Morus sp. (mulberry) , and Elaeagnus sp.(elaeagnus).

Based on the archaeological context of these samples, it is inferred that Populus sp. and Salix sp. species were more extensively utilized. These woods may have served as fuel, for constructing dwellings, and making for crafting daily utensils, which was because of their wood properties. Archaeological investigations further reveal that both caves were situated near rivers,which were favorable conditions for the growth for Populus sp. and Salix sp.. It could be inferred that these wood in the caves were collected by monks locally. Although the number of wood samples discovered is relatively limited, by integrating existing climatic research findings and historical literature records about this area, we deduce that the climate during this period fluctuated between cold and warm phases, while the vegetation surrounding the sites predominantly consisted of Populus sp., Salix sp. and some shrubs.