Drought (scPDSI) reconstruction of trans-Himalayan region of central Himalaya using Pinus wallichiana tree-rings

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

“…Our reconstruction also captured a range of changes in climate mentioned in other studies (Ahmad et al, 2004;Yu et al, 2014;Chen et al, 2019;Gaire et al, 2019). 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).…”

“…The dry period of 1645-1631 is also reflected in the treering-based drought variability of the Silk Road . Three mega-drought events in Asian history (Yadav, 2013;Panthi et al, 2017;Gaire et al, 2019), namely the Strange Parallels Drought (1756-1768), East India Drought (1790-1796), and Late Victorian Great Drought (1876-1878), were clearly recorded in our reconstructed PDSI. This could mean that widespread drought on the continent could be linked to volcanic eruptions (Chen et al, 2019).…”

“…However, we found that our drought periods are more consistent with the drought periods of the May-June reconstruction in the south-central Tibetan Plateau (He et al, 2018), such as 1593-1598 (1580-1598), 1647-1660 (1650-1691), 1785-1800 (1782-1807), and 1870-1878 (1867-1982). This difference may be due to differences in geographical location, species, and reconstruction indices, among others (Gaire et al, 2019). In addition, the lack of consistency between different data sets or regions might have been due to the dominance of internal climate variability over the impact of natural exogenous forcing conditions on multidecadal timescales (Bothe et al, 2019).…”

Spring Season in Western Nepal Himalaya is not yet Warming: A 400-Year Temperature Reconstruction Based on Tree-Ring Widths of Himalayan Hemlock (Tsuga dumosa)

“…This response is rather site-specific because of the inconsistent responses with the summer temperature and precipitation observed over Nepal. For instance, several studies from different locations in the Nepal Himalaya showed positive relationships with the summer (June-September) temperature and negative relationships with summer precipitation [26,38,71], whereas other studies showed the opposite response [27,29]. During the summer monsoon season, trees generally receive sufficient water; therefore, high temperatures during this period are conducive for photosynthesis and tree growth.…”

“…This holds especially true for Nepal, which hosts many tree species with proven dendrochronological potential [19][20][21] in high-elevation ecosystems, which are the crucial region for detecting climate change patterns on regional scales [22]. However, to date, only four temperature reconstructions [19,23,24], one precipitation and four moisture index [25][26][27][28][29] reconstructions, have been conducted for the central Nepalese Himalaya. Although available temperature reconstructions used different tree species from different locations, they share common low-frequency variations.…”