FLORISTIC AND VEGETATION DIVERSITY OF GADOON HILLS OUTER HIMALAYAS DISTRICT SWABI, PAKISTAN

An ecological study was conducted in summer to record the floristic and vegetation diversity of unexplored Gadoon Hills, Outer Himalayas District Swabi, Pakistan. Vegetation was analyzed using 10 nested, 10-m(2), 5-m(2) and 1-m(2) quadrats respectively for trees, shrubs and herbs in all the sites for determining density, cover and frequency of each recorded species. Floristic composition revealed 107 plant species of 98 genera and 54 families. The vegetation and its component flora is divided altitudinally in to sub-Himalayan semi-evergreen, Himalayan Chir pine and Himalayan Temperate zones, each with its component plant communities. The flora and vegetation exhibited hemicrpto-therophytic life form and nano-mesophillic leaf spectra. Majority of the species were mesophytic (63.55%) and annual with simple leaves. FIV, TIV and Mori index revealed that Asteraceae, Rosaceae, Poaceae, Mimosaceae, Pinaceae, Fagaceae, Lamiaceae and Papilionaceae were the dominant families in the investigated area.SIV identified that the top most species in decreasing order were Pinus roxburghii, Quercus dilatata, Acacia catechu and Heteropogon contortus. Of the 13 sites, 12 were heterogeneous. Most of the species occupied Classes I-III. Species diversity (0.05-0.29), species richness (0.89-2.14) and species maturity (42.0-76.67) were generally low in the investigated area. The area is highly degraded with nutrient deficiency owing to deforestation, overgrazing, over-exploitation and soil erosion, which are the major threats to the biodiversity of the area. Trees and shrubs are generally stunted and isolated. The area requires concerted ecological and conservation management efforts for the rehabilitation of the original vegetation with the participation of all stake-holders.