Prof. Li-Hung Lin from NTU RCFE joined the international research team including Princeton University and other world’s leading research institutes and top universities. The team integrated 3,800 microbial count data from the underground environment of land reaching a depth of more than 3,000 meters. Database of global surface temperature, heat flow, crustal type, etc. were combined to construct the relation between microbial density and depth under consideration of different factors like temperature and rock type. The number of microorganisms living in terrestrial underground environment around the globe was obtained, which was 2-6*10^29 cells. It approximately equals to 23-31 Pg pf carbon. It is a more accurate estimate, several times lower than that of past studies, which indicates the organic matter content of rocks or the density of suspended microorganisms in groundwater cannot serve as an indicator of microbial density at a specific depth.

The research has been the most comprehensive and systematic integrated analysis of terrestrial biosphere in underground environment. It reveals the deficiencies of discussing the role microorganisms play in the earth as well. The results were published in Nature Geoscience.

To read the article: The biomass and biodiversity of the continental subsurface