Drought reconstructions over the past 552 years based on minimum earlywood density in central Tianshan Mountains

Abstract

Tree-ring minimum earlywood density (MND) is a parameter that has been relatively understudied in paleoclimate reconstructions, with only a limited number of studies conducted in drought-prone regions. In this study, various tree-ring density parameters were generated based on Picea Schrenkiana in the arid central Tianshan Mountains. We found that the MND chronology exhibited robust signals of drought, while maximum latewood density (MXD) showed significant responsiveness to drought variability rather than strong temperature signals typically observed in high latitude or high altitude regions. These distinct climate response patterns of tree-ring density data can be attributed to the prevailing arid climate at our study site. Based on these results, we reconstructed the drought history from 1464 to 2015 and identified a wetting trend from the 1920s until the present times. By integrating various hydroclimate reconstructions, we observed a wetting trend in both the western and central Tianshan Mountains but a drying trend in the eastern Tianshan Mountains. This study highlights the potential of tree-ring density as a tool for global climate reconstruction.