Sanjeeb Bharali

Anthropogenic Disturbances Led to Risk of Extinction of Taxus wallichiana Zuccarini, an Endangered Medicinal Tree in Arunachal Himalaya

ABSTRACT: Species extinction is the major biodiversity crisis in the twenty-first century. Today, anthropogenic activities are causing extinction of many species of ecological and economic importance. Arunachal Pradesh, home of high biodiversity and endemism, has many species facing tremendous stress which are on the verge of extinction. Taxus wallichiana, an endangered tree species distributed in temperate forests, has the anti-cancerous chemical Paclitaxel (Taxol®). It has other important uses in Ayurveda, Tibetan, and Unani medicine. Currently, Taxol is recognized as the most effective drug for a variety of cancers. Owing to its high economic demand, unsustainable extraction, and over-harvesting, the species ranked in the endangered category and is at risk of extinction in Arunachal Himalaya. Regeneration from seed is very poor due to a long dormancy period (nearly 18 months) and it is slow to reach maturity in nature. Moreover, consumption of fruits by birds, monkeys, rats, etc., is causing regeneration failure. A very few populations survive in isolated pockets and they will become extinct in the near future if proper conservation measures are not initiated. Conservation measures either by in situ or ex situ, with community participation, can be undertaken. In situ conservation can be exercised by establishing sanctuaries, parks, reserve forests, etc. Ex situ conservation could be practiced by cultivating the species in gardens, parks, and also by tissue culture techniques. Furthermore, mass awareness and motivation of local people for large scale cultivation and preparation of bonsai to a certain height to harvest the leaves without damaging the whole tree may reduce pressure on wild populations. This may meet the market demand as well as conserve the species and will boost the rural economy while also providing employment opportunity for the local inhabitants.

Population Status of Rhododendron mechukae-A Newly Recorded Endemic Species from Eastern Himalaya, India

Population Status of Rhododendron mechukae-A Newly Recorded Endemic Species from Eastern Himalaya, India The present paper deals with a newly recorded Rhododendron species from Eastern Himalayas, India, which is categorized as a critically endangered species. Rhododendrons act as keystone species and maintain biological communities in the fragile higher altitudinal region of the Eastern Himalayas. However, due to various anthropological disturbances, which is further exacerbating by climate change impact, results in shrinkage of natural habitat of rhododendrons. This brings an urgent need of assessing the population status of the Rhododendron species in Eastern Himalayas. Keeping this in view, an attempt had been made to evaluate the population status of Rhododendron mechukae. The study revealed that the species have a very small population size with scattered individuals and shows a reverse J-shaped population structure. As a result of deforestation for fuel wood, as well as massive destruction of the habitats, the survival of this species is threatening. Therefore, effective conservation and management initiatives should be taken to protect this newly recorded Rhododendron species in its natural habitat.