A 424-year tree-ring-based Palmer Drought Severity Index reconstruction of Cedrus deodara D. Don from the Hindu Kush range of Pakistan: linkages to ocean oscillations

The rate of global warming has led to persistent drought. It is considered to be the preliminary factor affecting socioeconomic development under the background of the dynamic forecasting of the water supply and forest ecosystems in West Asia. However, long-term climate records in the semiarid Hindu Kush range are seriously lacking. Therefore, we developed a new tree-ring width chronology of Cedrus deodara spanning the period of 1537-2017. We reconstructed the March-August Palmer Drought Severity Index (PDSI) for the past 424 years, going back to 1593 CE. Our reconstruction featured nine dry periods (1593-1598, 1602-1608, 1631-1645, 1647-1660, 1756-1765, 1785-1800, 1870-1878, 1917-1923, and 1981-1995) and eight wet periods (1663-1675, 1687-1708, 1771-1773, 1806-1814, 1844-1852, 1932-1935, 1965-1969, and 1990-1999). This reconstruction is consistent with other dendroclimatic reconstructions in West Asia, thereby confirming its reliability. The multi-taper method and wavelet analysis revealed drought variability at periodicities of 2.1-2.4, 3.3, 6.0, 16.8, and 34.0-38.0 years. The drought patterns could be linked to the large-scale atmospheric-oceanic variability, such as the El Nino-Southern Oscillation, Atlantic Multidecadal Oscillation, and solar activity. In terms of current climate conditions, our findings have important implications for developing drought-resistant policies in communities on the fringes of the Hindu Kush mountain range in northern Pakistan.