Potential distribution, habitat composition, preference and threats to Spikenard <Nardostachys jatamansi> (D.Don) DC. in Sakteng Wildlife Sanctuary, Trashigang, Bhutan

Bhutan stands out as one of the native areas where Nardostachy jatamansi grows. At an international level, a rampant rate of harvesting of its rhizome for medicinal and religious purposes has resulted in the species being categorized as ‘Critically Endangered’ as per the IUCN Red List Assessment, 2025. A survey was conducted in August 2021 within Sakteng Wildlife Sanctuary to identify the growing area of N. jatamansi within the sanctuary, determine species composition in the N. jatamansi growing area, assessing the threat within the sanctuary, and the potential distribution using current, and future climate scenarios. The survey found most of the species favouring rocky outcrops and high altitudes, given the harsh climatic conditions it tolerates. The studies recorded 19 individuals per m2 of the species across Merak and Sakteng and presented Shrubs as dominant life forms and Carex spp as the indicator species in N. jatamansi growing area. We found 49.8 km2 of the sanctuary area as the potential suitable habitat for N. jatamansi, with elevation and temperature-related variables as the most contributing factors in determining its distribution. Change in area under the ssp 245 future climate scenario for year 2041–2060 and 2061–2080 showed net increase in area of 125.5 ha and 126 ha respectively from current to future.