Abstract:
Dendrochronological studies were conducted based on the data of 41 different mature stands of moist temperate areas of southern Himalayan and Hindukush region of Pakistan. Wood samples as cores were obtained from 222 trees including those of Pinus wallichiana A.B. Jackson, Abies pindrow Royle, Cedrus deodara (Roxb.) G. Don., Picea smithiana (Wall.) Boiss., and Taxus fuana Nan Li & R.R. Mill., using an increment borer. Age and growth rates of these trees were estimated. Correlations were sought between the diameter / age, diameter / growth rate and age and growth rate on the basis individual stands and on an overall basis. More than 50% correlations were found to be significant. Relationship between the growth rate of dominant conifer species with environmental factors (soil nutrients, edaphic factors and topographic factors) was also sought. In general, they disclosed poor relationships. Growth rate of Abies pindrow showed weak correlation (p<0.1) with salinity, total dissolved salts and water holding capacity while that of Cedrus deodara also exhibited weak correlation (p<0.1) only with total nitrogen of soil. These significant correlations did not show any particular trend of growth and development of dominant conifer species and may be spurious. Pinus wallichiana is widely distributed species in the moist temperate area but its growth rate did not exhibit any relationship with the measured environmental variables. It is shown that largest tree, in terms of diameter, is not necessarily the oldest. Highest growth rate (1.7 ± 0.5 years/cm) was recorded for Pinus wallichiana while slowest growth rate (8.4 ± 0.7 years/cm) was recorded for Cedrus deodara.
