资源环境科技发展态势分析平台

Yak is an integral part of the livelihood of highlanders in Indian Eastern Himalaya where only subsistence agriculture is possible due to its difficult terrain and harsh climate. The tribal households of Lachen and Lachung in North Sikkim rear yaks at an altitude of 3000 to 5000 m in semi-pastoral system which is highly dependent on temperature and snowfall pattern. Any change in climatic factors is expected to affect the yaks and livelihood of the yak herders. Hence, an explorative study was conducted to understand how the pastoral yak rearing system is changing in the region with change in climate. The estimated temperature increment was 0.03-0.04 degrees C/annum which is corroborated by herders' perceptions. They observed that the amount of snowfall has receded, especially in lower altitudes and the snowfall period shifted from November-December to January-March. The commencement of upward migration of yak herders advanced by 15-30 days due to increase in March temperature and the migration span extended by 45 days now. The downward migration is restricted to mid alleviation (2750-3000 m) now which was earlier about 2000 m whereas the upward migration has gone up farther about 500 m due to increasing temperature and unavailability of quality pasture. The study revealed that the pastoral yak rearing in North Sikkim is transforming to cope the impending climate change. However, to reduce the vulnerability of yak, research and extension efforts/policies should be concentrated on fodder production and pasture management suiting to the awaiting climate change.