Status and Conservation Threats of Picrorhiza scrophulariiflora Pennell; (Scrophulariaceae): An Endangered High Valued Medicinal Plant of the Indo-China Himalayan Region

摘要

Picrorhiza scrophulariiflora Pennell. is an endangered medicinal herb of the Indo-China Himalayan region which urgently needs to be conserved in situ by preventing animal grazing as well as unsystematic harvesting of its rhizomes. Habitat preferences,population structures, existing status, conservation threats, correlation of soil characters with aerial and underground biomass as well as ethno-medicinal values of Sikkim Himalayas were studied. The present study revealed that analytical features suchas density, frequency, abundance, relative density, relative frequency, abundance-frequency ratio, etc., were low in all populations, which indicates the requirement of immediate conservation planning. Open pastures, rocks, crevices, rocky terrain and moist areas were found to be the preferred habitat of this species. However, animal grazing, random collections of its rhizome as well as other associated rare medicinal species such as Bergenia ciliata, Rhododendron anthopogan, Rheum australe and Saussurea nepalensis by locals were the major threats to existing populations which has led to a drastic change in the original phytosociological structure of P. scrophulariiflora, resulting in rapid habitat loss. However, in order for conservation and sustainable utilization through cultivation, an attempt has been made to identify elite germplasm with higher underground biomass. Additionally a correlation between aerial and underground biomass growth and important soil characteristic such as available nitrogen, organic carbon, moisture content, soil pH and altitude gradients was also established.