Spatial patterns and diversity of the alpine flora of Deosai Plateau, Western Himalayas.
The Western Himalayan alpines are among the most diverse ecological locations having diverse vegetation and provide a wide range of ecosystem services. The complex and dynamic Deosai Plateau is the World's 2nd highest plateau with an average elevation of 4500 m. Current study was designed to investigate floristic diversity, phytosociological attributes, endemism and conservation status of flora of Deosai National Park, North Pakistan. Vegetation sampling was carried out by using random sampling through quadrat method at selected sites. A total of 8 plant communities were recorded from the area. The Floristic composition of present study consisted of 132 species belonging to 101 Genera and 41 families. Hemicryptophytes were recorded as the dominant life form followed by geophytes and Therophytes whereas Leptophylls and Nanophylls were dominant leaf spectra. The average value of Shannon diversity was calculated as 1.383 whereas Simpson diversity was 0.447. The calculated values of Evenness and richness were 0.882 and 1.185 respectively whereas the average maturity index was 30.27. A total of 63 plants species were found to be threatened having very low (<1%) importance values with 4 species recorded as critically endangered and endangered. Phytogeographic investigations revealed that 41 plant species (33%) were endemic to the Whole Himalayas, 18 species (14%) Endemic to Western Himalayas, 27 plants (22%) as tropical Asian and 34 plant species (27%) recorded as cosmopolitan. Principal component analyses (PCA) revealed Moisture and altitude as the key factors governing the species composition and community structure in the study area. Grazing pressure was observed as a major threat to the palatable species. It is recommended to extensively explore the population dynamics of endemic species as well as the spread of invasive species in DNP with the focus to conserve the precious threatened flora.