Distribution dynamics of Arnebia euchroma (Royle) I.M.Johnst. and associated plant communities in Trans-Himalayan Ladakh region in relation to local livelihoods under climate change

Abstract

The impact of climate change on the mountain ecosystems globally can be better sensed through monitoring of structural shifts in vegetation vis-à-vis livelihoods of mountain communities. Here, we report the distribution pattern of an ecologically vital species, Arnebia euchroma, and its co-occurring communities. The species is considered as an indicator of ecosystem health and is linked to human wellbeing in mountain systems in the Trans-Himalayan range of Ladakh. Through intensive field surveys for two years, we recorded 127 species belonging to 41 families associated with A. euchroma across habitats, majority of which are herbaceous with perennial life cycle. The hemicryptophytes were found to be the most dominant followed by the geophytes and phanerophytes. Highest average importance value index (IVI) was found to be for A. euchroma (37.93) as against very low IVI values for 41.73% of the total flora, which reflects the need for conservation. Our generalized linear model results demonstrate the role of A. euchroma in maintaining and enhancing the maturity index of the communities with increasing altitude. The low maturity index of the communities indicates the influence of anthropogenic pressures and rather harsh environmental conditions. The Principal Component Analysis and Cluster Analysis correlated the investigated communities geographic features and microclimates to identify the dominant taxa and unique species assemblages in the local flora. Since A. euchroma and its associated assemblages are linked to local livelihoods in Ladakh, yet quite vulnerable to climate change, the importance of our results for future research and long-term monitoring in the Trans-Himalayan mountains is discussed.