Impacts of environmental change and human activity on microbial ecosystems on the Tibetan Plateau, NW China

Microorganisms play important roles in maintaining ecosystem functions. It is poorly known, however, how microbial ecosystems respond to environmental changes and human activities. The purpose of this paper is to demonstrate that the microbial record in lake sediments and ice cores contains a wealth of paleoenvironmental and paleoclimatic information. Saline lakes on the Tibetan Plateau exhibit multiple environmental gradients and have accumulated thick sequences of sediments through time. Microbial abundance and species diversity vary considerably along environmental gradients across the plateau. Studies of lake sediments reveal that wet and warm climates are correlated with high bacterial abundance and diversity, whereas cold and dry climates result in low abundance and diversity. Recent human activities have enhanced sulfate reduction in lake sediments. Ice cores from the plateau reveal that bacterial abundance and diversity are positively correlated with dust particle concentration and