干旱区生态环境知识资源中心

Inventorying of plant biodiversity of Haramosh and Bugrote valleys (District Gilgit, Gilgit-Baltistan, Pakistan) was done for fourteen years from 2001- 2014. The fourteen years inventorying revealed a rich plant biodiversity consisting of 232 species belonging to 106 genera and 34 families of flowering plants. The Alpine zone had 18 genera with 4 or more species; Pedicularis with 10 species was the largest genus of this zone, followed by Potentilla and Carer (each with 9 species) and Draba (8 species). Genera containing 9 or 10 species occurred only in Alpine zone. In the Alpine zone, 15 of the larger families were represented by 189 species, forming 81.46% of the Alpine flora. Although the highest number of species belonging to these larger families was present in the subalpine zone, but in terms of percentage their contribution was the highest in the Alpine flora. Percentage-wise the contribution of these families gradually increased from Desert zone to Alpine zone, because of their particular distribution patterns. Although the total number of species was the highest in the Subalpine zone, but in the species specific to any one zone, the Alpine zone had the highest number, that is, 96 of the total 232 species of Alpine zone were exclusively found in this zone only. Out of these 96 species specific to the Alpine zone, 53 belonged to such 22 genera that were exclusively found in the Alpine zone only. The Alpine zone was characterized by herbs and low shrubs, with Potentilla species as the dominants. A clear trend of migration of certain species both from lower to higher latitudes and altitudes was observed. The species richness index of Alpine zone however showed increasing trend probably due to species migrations towards the alpine zone. The major threats to the plant biodiversity were recognized as the deforestation and habitat loss due to over-exploitation of species, over-grazing by livestock, and climate changes due to global warming, which were manifested as less and erratic precipitation and steadily rising temperatures over the past fourteen years.