Phytodiversity and endemic richness in high altitude Rama Valley, Western Himalayas, Northern Pakistan

Abstract

Vegetation diversity, distribution and species endemism were studied in high altitude (>3300 m) Himalayan plateau in Northern Pakistan. A heterogeneous vegetation structure and distribution was observed due to complex environmental variables. A total of 83 species belonging to 31 families were recorded from the area. The recorded range of species diversity (1.02 to 2.17) and species richness (1.19 to 1.97) was very low as compared to other Himalayan regions. Detrended correspondence analyses (DCA) revealed slope steepness and associated moisture gradient as the main limiting factors controlling vegetation distribution and community structure. Species diversity and richness were negatively whereas evenness was positively correlated with slope steepness and moisture content. Chorological spectrum of vegetation revealed a high (41%) level of species endemism with 34 recorded Himalayan endemic species. Dominance of unpalatable species indicated prevalent impacts of overgrazing on the local flora and possible threats to endemic plant diversity. The high species endemism suggests the conservative value of the area. Key words: Deterrended correspondence analyses, Himalayas, moisture gradient, species endemism, slope steepness.