Climatically induced anomalies in tree-ring structure of Abies pindrow (Royal ex D. Don) and Taxus baccata (L.) growing in Hindu-Kush mountainous region of Pakistan

Abstract

Dendroclimatic potential from Abies pindrow Royal ex D. Don. (fir) and Taxus baccata L. (yew) was investigated by developing four different types of tree-ring width chronologies (by ARSTAN program) in a mixed broadleaf forest of Kalam, KP, Pakistan. Firstly, measured tree-ring width series were cross-dated and identified the best and least (cross-matched with master plot) samples with the most applied Skeleton Plot Model (SPM) method alongside checking the quality through statistical program (COFECHA). Tree-ring attributes (age, growth rate and earlywood and latewood) were also measured with maximum age (677 years) was observed in fir plant and maximum growth rate (6.096 mm/year) in yew plant with clear demarcations of earlywood and latewood formation. Yew trees were observed to be more sensitive species towards climatic variations (expressed population signal = 0.856, mean sensitivity = 0.321 and signal to noise ratio = 3.214) while fir trees were comparatively less affected by climatic alterations of the study site (expressed population signal = 0.852, mean sensitivity = 0.314 and signal to noise ratio = 2.453). Correlation between tree-ring series of T. baccata with the master series was found to be more significant as compared to A. pindrow after developing series plots of both the species by using package dplR in R. Potential ecological and anatomical explanations for these results were also discussed. Sensitivity of samples showed good climatic signals which are valuable for dendroclimatic growth response investigations leading to reconstruction of past climate as well as possible future climate predictions.