LAUSR

Tree ring investigations at the high altitude mountains of the Karakoram-Himalaya, northern Pakistan have received limited attention concerning the climate-tree growth relationship studies. To test the climate-growth relationship, we developed four tree-ring width (TRW) standard chronologies represented by Pinus wallichiana and Picea smithiana from four sites in the Bagrot (BGR), Astore (AST), Phaphorash (PPR), and Naltar (NLT) valleys in northern Pakistan, respectively. These chronologies spanned 585, 514, 330, and 470 years, respectively. The tree growth was sensitive to spring precipitation and summer temperature, such as AST and PPR chronologies were sensitive to summer temperature. TRW chronologies of BGR and NLT were sensitive to spring precipitation and drought. Principal Component 1 (PC1) chronology was sensitive to spring temperature and showed an overall weak correlation with Palmer Drought Severity Index (PDSI). These multi-sites based study revealed variable climate-growth response, highlighting the heterogeneity in microclimate on a local scale.