FLORISTIC COMPOSITION AND PHYTOSOCIOLOGICAL STUDIES OF HAZAR NAO HILLS, DISTRICT MALAKAND, KHYBER PAKHTUNKHWA, PAKISTAN

A field study was conducted to investigate the floristic composition and phytosociology of the Hazar Nao hills, District Malakand, Khyber Pakhtunkhwa. For study purpose the whole area was divided into 5 Zones. In each Zone 25 sites were selected randomly. Data were recorded from May-September, 2014, by using 1 sq. meter quadrate. The size of Zone has a direct proportion to the distance between the quadrates as the number of quadrates is same for each Zone. Twenty four plant species belong to 13 families were identified from the study area. Seventeen plant species were identified as dicot, 6 monocot and 1 pteridophyte. Out of the 23 angiosperms 5 belong to poaceae, 4 lamiceae and asteraceae each, 2 belongs to polygonaceae as important families, distributed all over the Hazar Nao hills. The highest total weed density 119.71 plants m^-2 was recorded in Zone-1, followed by 109.08, 98.22 91.07 and 73.34 at Zone-2, Zone-3, Zone-4 and Zone-5, respectively. The mean weed density across the Zones depicted (21.67) for Saccharum spontaneum as the dominant weed followed by Micromeria biflora (11.57). The highest relative density % (24.09) was recorded for S. spontaneum in Zone-1 followed by 21.89 at Zone-3, 21.74 at Zone-5 and 21.05 at Zone-2. The major weed communities existing in the area consisted of S. spontanium, M. biflora and Apluda mutica. The highest mean frequency % (82) was observed for S. spontaneum which was present at all Zones while lowest was recorded (20) for Chenepodium album (L). The mean highest relative frequency % (8.76) was also observed for S. spontaneum while lowest (2.21) was recorded for Conyza canadensis. The Polygala abyssinica (L), Oxalis corniculata (L) and Xanthium strumarium were having the lowest mean relative frequencies, declaring them as insignificant weeds of the area. The data shows that the highest importance value % (16.24) was recorded for S. spontaneum in Zone-5 followed by (15.79) at Zone-1. S. spontanum is the most prevalent weed at all the Zones with high (15.35%) mean importance values. Similarly the highest importance value constancy index (IVCI) (61.4) was found for S. spontaneum while the smallest IVCI value (5.92) was recorded for C. canadensis. Average importance value (AIV) and IVCI value confirms the predominance S. spontaneum, M. biflora, O. limbata and T. minuta form the Hazar Nao hills. The supremacy of S. spontanum is due to its stress tolerance, invasiveness, higher growth rate and high fecundity. It is concluded that the plants with grazing, feed or medicinal value are becoming rare and less frequent besides plants intrinsic characteristics of being vulnerable to environmental and anthropogenic stresses.