Population ecology and niche modelling of endangered Arnebia euchroma in Himachal Pradesh, India-An approach for conservation

For the restoration and rehabilitation of a species, comprehensive information on the ecological elements and potential habitats are essentially required to the conservationists. This has necessitated initiating studies on habitat and population ecology of the threatened species. Keeping this in view, population ecology and niche modelling of endangered Arnebia euchroma in Himachal Pradesh was studied. Total 49 populations of A. euchroma were studied between 3325-4587m amsl in the Lahaul and Spiti and Kinnaur districts of Himachal Pradesh. Most of the populations (25) were found in steep slope and fall in east, north, north-east, north-west, south, south-east, south-west and west aspects. Maximum populations (11) were represented in the east aspect, followed by north and west (9 each) and northeast and northwest (6 each) aspects. Among the populations, richness of shrubs ranged from 1–7 and herbs 4–36; total shrubs density 2–119 Ind 100 m⁻²; total herbs density 460–7055 Ind 100 m⁻²; Concentration of dominance for shrubs 0.26–1 and herbs 0.05–0.37 and Species diversity (H’) for shrubs 0.0–1.56 and herbs 1.26–3.29. Biological features, aspects, slope and pressure contributed to the critical population status of the A. euchroma. The particular geographical distribution (2022 km²) under semi-arid conditions of the species indicated its habitat specificity. The present investigation revealed that A. euchroma populations showed fragmented pattern of distribution in the cold desert ecosystem. Therefore, re-introduction of A. euchroma in highly suitable habitat i.e., north-western gentle dry slope with high pH (alkaline soils) and low total nitrogen, moisture, carbon and organic matter is suggested.