Vegetation attributes and spatial patterns of treeline communities in Himachal Pradesh Western Himalaya

Abstract

Alpine treelines are fragile and environmentally sensitive ecoregions. They contribute significantly to human welland#8208;being by providing ecosystem benefits. In the current scenario, where changes in climatic conditions are of major concern, documenting their attributes becomes important. The present study focused on species composition, stand structure, phenology, and soil characteristics of treeline communities in Himachal Pradesh, western Himalayas. A total of six treeline sites were selected and sampled for herbs, shrubs, and trees using 1 m2, 25 m2, and 100 m2 plots, respectively. The study underlined the rich plant diversity of treelines and its importance in harbouring threatened, medicinal, and aromatic plant species. Diversity indices of herbs and shrubs significantly varied among the treelines. Moreover, Betula utilis dominated the treeline and the demographic traits of which varied among the sites. Very few seedlings and saplings were observed above the treelines indicating recruitment limitation in the area. Time series analysis of digital images revealed seasonal changes in the Betula forest canopy. Relative changes in red, green, and blue color indices reported sensitivity to canopy coloration and indicated different phenophases. The studied treelines were characterized by a mosaic of soil types that depend on locally varying ecological and environmental conditions. The soils were acidic in nature. Moreover, the study provided baseline data from the white spot region that has global implications. The timeand#8208;lapse camera setup facility for phenological monitoring is a pioneer and provides crucial insights into the alpine treeline in the Indian Himalayan Region. newline