Population Assessment and Ecological Niche Modelling of Threatened Medicinal Plant Species (Ephedra Gerardiana Wall. Ex Stapf) in Cold Desert Biosphere Reserve, Trans Himalaya - An Approach for Conservation and Reintroduction

The high altitude cold desert regions are the richest store house of many high value medicinal plants. Ephedra gerardiana Wall. ex Stapf is one of the oldest xerophytic shrub found in arid and semi arid regions of Cold Desert Biosphere Reserve (CDBR), Trans Himalaya. Ephedra is a good source of essential phytochemicals and traditionally being used to treat various diseases. Therefore, present study is an attempt to make effective conservation strategies on the basis of population assessment and niche modelling approach for its successful reintroduction in the BR. We found 34 natural populations of E. gerardiana across entire BR; the density was ranged between 5-245 individual/25m2. Maximum density was observed in dry alpine slope, scree and bouldary habitats. Maximum entropy distribution modelling output reveals that only 6.9% area of the whole BR is highly suitable for its growth and development. Strong correlation exists between species occurrence and bioclimatic variables. Precipitation seasonality and precipitation of the coldest quarter are the most influential variables. Low density population of E. gerardiana (modelling result) can be taken under consideration for monitoring and reintroduction. Thus, population assessment and niche modelling together provide useful recommendations for restoration and designing short and long term conservation planning. Keywords: Ecological niche modelling, Cold Desert Biosphere Reserve, Bioclimatic Variables, MaxEnt, Ephedra gerardiana.