Nasrullah Khan;Syed Shahid Shaukat;Moinuddin Ahmed;Muhammad Faheem Siddiqu

Laboratory of Dendrochronology and Plant Ecology Department of Botany, Federal Urdu University of Arts, Science and Technology, Karachi, Pakistan;Department of Botany University of Malakand, Chakdara Dir Lower, Pakistan;Dept. of Botany, University of Karachi, Karachi, Pakista;Dept. of Botany, University of Karachi, Karachi, Pakistan

environmental relationship;multivariate analysis;cluster analysis;ordination;anthropogenic factors;forest, Hindukush range;LANDSCAPE PATTERNS;NATIONAL-PARK;DYNAMICS;GRADIENT;PHYTOSOCIOLOGY;COMMUNITIES;DIVERSITY;VALLE

We investigated the composition of plant communities to quantify their relationships with environmental parameters in the Chitral Hindukush range of Pakistan. We sampled tree vegetation using the Point Centered Quarter (PCQ) method while understory vegetation was sampled in 1.5-m circular quadrats. Cedrus deodara is the national symbol of Pakistan and was dominant in the sampled communities. Because environmental variables determine vegetation types, we analyzed and evaluated edaphic and topographic factors. DCA-Ordination showed the major gradient as an amalgam of elevation (p<0.05) and slope (p<0.01) as the topographic factors correlated with species distribution. Soil variables were the factors of environmental significance along DCA axes. However, among these factors, Mg2+, K+ and N2+ contributed not more than 0.054% 0.20% and 0.073%, respectively, to variation along the first ordination axis. We conclude that the principal reason for weak or no correlation with many edaphic variables was the anthropogenic disturbance of vegetation. The understory vegetation was composed of perennial herbs in most communities and was most dense under the tree canopy. The understory vegetation strongly regulates tree seedling growth and regeneration patterns. We recommend further study of the understory vegetation using permanent plots to aid development of forest regeneration strategies.