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

Abstract

Abstract. 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 Niño–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.

Tree rings of Rhododendron arboreum portray signal of monsoon precipitation in the Himalayan region

“…A significant positive correlation of our reconstructed PPT JJA with reconstructed JJA PDSI (r = 0.20, p < 0.001) from monsoon Asia during the period 1780-2005 (Cook et al, 2010) and May-September precipitation (r = 0.14, p < 0.05) from Bhutan Himalaya (Sano et al, 2013) during the period 1780-2011 further indicates regional linkages. The late 18th century droughts from 1785 to 1794s in JJA PDSI (Cook et al, 2010), March-September precipitation (Sano et al, 2013), March-September PDSI (Ahmad et al, 2020), and March-July precipitation (Singh et al, 2009), as well as historical East India Drought (1790-1796), are also common in our reconstructed precipitation data (Figure 8). Similarly, the dry episodes of 1830-1836 synchronize with May-September precipitation reconstruction (Sano et al, 2013).…”

“…Similarly, the dry episodes of 1830-1836 synchronize with May-September precipitation reconstruction (Sano et al, 2013). The other common dry phase of 1865-1875 in March-September PDSI (Ahmad et al, 2020), MS precipitation (Sano et al, 2013), May-June PDSI (He et al, 2018), and the previous year October to current year September precipitation reconstruction (Singh et al, 2021) FIGURE 8 Comparison of (A) reconstructed PPT JJA with (B) JJA PDSI reconstruction from Asia (Cook et al, 2010), (C) May-September (MS) precipitation reconstruction from Bhutan Himalaya (Sano et al, 2013), and (D) previous October-Current September (pOcS) precipitation reconstruction from Indian Western Himalaya (Singh et al, 2021). All the line plots are smoothed by a 10-year low-pass smoothing filter.…”

“…During the monsoon season, years with high snowfall in the preceding winter and spring are followed by summer with less monsoon rain (Blanford, 1884;Bamzai and Kinter, 1997). This is further reinforced by the idea that greater wetness in the northwestern Himalayas has influenced anomalous glacier progress in recent years and that increasing snowfall may contribute to dry conditions in summer (Yadav et al, 2017;Ahmad et al, 2020). Interestingly, since 2010, an increase in Indian summer rainfall has been reported in several gridded and observed datasets throughout the Indian subcontinent (Jin and Wang, 2017).…”

Increasing Incidence of Droughts Since Later Part of Little Ice Age Over North‐Western Himalaya, India

“…The SPI12‐May reconstruction revealed relatively wetter conditions in the early 17th to the mid‐18th century (1613–1750s CE), where SPI values are close to the long‐term mean, however, the late 18th to the early 21st century (1760s–2017 CE) showed repeated occurrence of mega‐droughts over the region (Figure 3b). The long‐term drought records from the Himalaya, though limited (Ahmad et al., 2020; Bhandari et al., 2019; Cook et al., 2010; Gaire et al., 2019; Panthi et al., 2017; Ram, 2012; Singh et al., 2017; Yadav, 2013; Yadav et al., 2015, 2017), show large‐scale spatial hydroclimatic variability. A comparison of present SPI12‐May series with other drought records developed from the high‐altitude western Himalayan region where precipitation is largely governed by the midlatitude westerlies during winter and spring seasons was done.…”

Radial growth, present status and future prospects of west Himalayan fir (Abies pindrow Royle) growing in the moist temperate forest of Himalayan mountains of Pakistan

“…However, this statement varies from species to species and even from site to site. For example, in a dry region the species mostly grow at medium altitudes and show marks linked with rainfall and drought (Ahmad et al 2020). In general, concerning the radial growth with increasing altitude, the positive effect of precipitation in the lowlands changes to the negative effect in mountainous areas (Sidor et al 2015;Putalová et al 2019;Vacek et al 2019).…”