68 - Elevational gradience in soils and small mammals from the East Himalayas, China

Mercury (Hg) is a long-distance transported pollutant, which cause concerns in remote mountains, including the highest ecosystems in Himalayas. However, little research exists regarding to Hg bioaccumulation in terrestrial wildlife, as well as its driving factors in this region. Surface soil and small mammalian samples were collected from the Lebu Valley, East Himalayas of China, to understand the Hg bioaccumulation along a 2700-m elevational gradient between 2300 and 5000 m a.s.l. The Hg concentrations in soil were measured and predicted mostly by vegetation type as well as soil organic matter, while hair Hg of small mammals showed deeply influenced by soil Hg. Notably, soil and hair Hg were both enhanced in low and mid-elevations, which overlapped the distribution ranges of a majority of mammals, including threaten species. Together, our findings indicate that Hg contamination in this area might pose a potential threat to the top predators that consuming small mammals directly or indirectly. Furthermore, our data provide insights into Hg dynamics in the highest mountain terrestrial systems and provides baseline for biomonitoring for reduction of Hg emission.