Altitudinal Variation in Floristic Composition and Phytosociology of Temperate Forests in Langate Forest Division of Kashmir Himalayas

Abstract

The present study investigates the altitudinal variation in floristic composition and phytosociological attributes of temperate forests in the Langate Forest Division of the Kashmir Himalayas, with a particular focus on habitats of Arnebia benthamii, a critically rare and medicinally important alpine species. The study area, located between 1590 and 4308 m a.m.s.l., is characterized by a temperate continental climate and diverse vegetation types along its altitudinal gradient. Vegetation sampling was conducted across three distinct elevations—3000 m, 3300 m, and 3600 m—using the quadrat method for trees (10×10 m), shrubs (5×5 m), and herbs (1×1 m). Species frequency, density, and Importance Value Index (IVI) were calculated to assess community structure and species dominance. A cumulative total of 6 tree, 10 shrub, and 52 herbaceous species were recorded. Species composition and structure showed marked altitudinal variation. At 3000 m, Acer caesium, Viburnum grandiflorum, and Sibbaldia cuneata were dominant among trees, shrubs, and herbs respectively. At 3300 m, dominance shifted to Betula utilis, Salix denticulata, and again Sibbaldia cuneata among respective layers. At the highest altitude (3600 m), Betula utilis, Berberis jaeschkeana, and Bergenia ciliata showed maximum IVI among trees, shrubs, and herbs respectively. Notably, Arnebia benthamii was restricted solely to the 3600 m elevation, underscoring its narrow ecological amplitude and highlighting its vulnerability to climatic and ecological shifts. A gradual decline in species richness and density was observed with increasing altitude, likely due to lower temperatures, reduced soil fertility, and shorter growing seasons. High-altitude medicinal species like Aconitum heterophyllum and Saussurea costus exhibited low IVI values, raising serious conservation concerns under projected climate change scenarios.