Anthropocene is a new geological concept, which indicates that human activity has become an active agent in changing the Earth’s systems. However, the Anthropocene still requires a great deal of stratigraphic evidence to be formalized by the International Commission on Stratigraphy.
The Sihailongwan Maar Lake has just been selected as a potential auxiliary site of Global boundary Stratotype Section and Point (GSSP) for demarcation of the Anthropocene by the Anthropocene Working Group (AWG). This site is located in a relatively remote area in Jilin Province in the northeastern China with little human disturbance.
As a typical crater lake there is no inlet and outlet and thus it mainly receives atmospheric deposition, reflecting environmental change and human activities over large scales. The sedimentary succession is composed of distinct annual varve layers that could provide annual-scale chronology with high time-resolution records.
Researchers from the Institute of Earth Environment, Chinese Academy of Sciences and Ume? University, applied the sedDNA technology and examined the responses of lake microbial eukaryotic communities to human activities over the past 160s years in the Sihailongwan Maar Lake.
They observed an acceleration of the rearrangements of microbial community since the 1950s, which was in good agreement with the rapid increase in other anthropogenic contaminants such as, heavy metals, spheroidal carbonaceous particles, polycyclic aromatic hydrocarbon, fossil fuel soot fractions and nutrients. These results indicated that human activities might have led to the irreversible effects on lake ecosystems.
The findings provide biostratigraphy evidences of the impact of human activities on lake biota, and further supports the boundary of the Anthropocene occurring in the mid-20th century, as proposed by the Anthropocene Working Group.
Contact: BAI Jie, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China. Email: baijie@ieecas.cn