Conclusions
This study reports the BBC and FBC in main biomes and presents the first
global maps of BBC and FBC in 0-30 cm topsoil. The global FBC and BBC
were estimated to be 12.56 (6.64 ~ 16.42) Pg C and 4.34
(0.47 ~ 10.26) Pg C, respectively, in 0-30 cm topsoil.
The FBC, BBC, and F:B ratio showed clear distribution patterns on a
global scale. Significant trends were observed along meteorological
parameters (MAP, MAT, ST, and SM), vegetation productivity
(Croot and NPP), and edaphic properties (soil texture,
bulk density, soil pH, SOC, TN, and C:N ratio). The FBC and BBC were
primarily determined by edaphic properties including sol texture, soil
pH, bulk density, and SOC, the F:B ratio was mostly driven by climatic
variables, particularly MAP and MAT. The biogeographic patterns of BBC
and FBC suggest that multiple mechanisms synergistically affect soil C
and nutrient cycling globally. Our study creates a benchmark for
explicit use of microbial distribution and its underlying mechanisms for
predicting soil C and nutrient cycling and biosphere-atmosphere
feedbacks in a changing climate.