Impact of bark removal on survival of Taxus baccata L. (Himalayan yew) inNanda Devi Biosphere Reserve, Garhwal Himalaya, India

摘要

The Himalayan yew (Taxus baccata L.) is widely but sparsely distributed along the cool temperate belt between 2600 and 3300 rn asl of the Nanda Devi Biosphere Reserve (NDBR), Garhwal Himalaya. Traditionally, the bark of this plant is used for preparing beverages locally called Namkin Chay, medicines and its wood as a timber in various regions of the Himalaya. However, due to its excessive collection for use in anti-tumour and anti-cancer drugs, the population of this, species has been reduced to a large extent. A study carried out between April 1997 and October 2000 showed that the trees with average girth of 10-90 cm were damaged through bark-stripping practices. The average consumption and collection of the bark was estimated to be 1.7 kg/family/year in the buffer zone villages of NDBR. It was noticed that the growth and survival of this species declined significantly when the bark was removed beyond a limit of average bark thickness (0.43 cm). Since bark collection is an important traditional activity and directly linked with the health and livelihood of the local people, it cannot be banned or stopped. It is suggested that if bark-removing practices, are applied appropriately with minimum depth of 0.2-0.3 cm from around the circumference of the trees (> 40 cm. cbh trunk) in a scattered manner, there will be minimum harmful effect on growth and survival of the trees. This paper describes the indigenous uses of Taxus baccata, impact of bark removal on survival and appropriate strategies, for conservation/management of this species.