Plants of the hunza valley (central karakorum), northern pakistan: ecology, diversity, and conservation

The present paper elaborates the results of vegetation and floristic research carried out in the valley of Hunza, Central Karakorum Mountains, northern Pakistan. The field surveys conducted from 2011 - 2012 ended with the collection of 324 species in 183 genera and 48 families. Based on geo-climatic conditions and floristic assemblage the vegetation of the studied area can be categorized into three altitudinal belts i.e. temperate, sub-alpine, and alpine. Altitude exhibits profound impacts on the species richness, composition, and surrogacy. The species diversity declined with elevation and maximum species richness was observed at the temperate belt. Asteraceae was the most presented family with 83 species followed by Poaceae (29 spp.), Fabaceae (16 spp.), and Cyperaceous (16 spp). Perennial herbs (77%) were the leading habit with subdominating shrubs (11%) and annuals (9%). In life-form categories, hemicryptophytes presented 249 species followed by therophytes and nanophanerophytes with 29 species each. Similarly, the common habitat of dry mountain slopes support maximum species i.e. 106 species followed by ruderal (90 spp), and moist mountain slopes (84 spp.). The assessment for quantitative thresholds for conservation revealed that habitats of 28 taxa were observed unstable, 255 taxa exhibited habitat specificity, 75 showed small population size, and 65 presented small geographical range. The application of IUCN Red List Criteria 2001 (Version 3.1) disclosed that 38 species fell in critically endangered, 32 vulnerable, and 10 endangered categories. The current ecological and floristic appraisal of the studied area would be effective to devise and strengthen the conservation strategies of climatically fragile mountain ecosystems.