Soil Property, Rather than Climate, Controls Subsoil Carbon Turnover Time in Forest Ecosystems across China

Subsoil (0.2–1 m) organic carbon (C) accounts for the majority of soil (SOC), and SOC turnover time (τ, year) is an important index C stability sequestration capacity. However, estimation subsoil τ identification its dominant environmental factors at a regional scale lacking in regards to forest ecosystems. Therefore, we compiled dataset with 630 observations investigate influencing ecosystems across China using structural equation model (SEM). The results showed large variability from 2.3 896.2 years, mean (± standard deviation) 72.4 ± 68.6 years; however, one-way analysis variance (ANOVA) that differed significantly types (p = 0.01), slowest obtained deciduous-broadleaf forests (82.9 68.7 years), followed by evergreen-needleleaf (77.6 60.8 deciduous-needleleaf (75.3 78.6 needleleaf broadleaf mixed (71.3 80.9 while fastest appeared evergreen-broadleaf (59.9 40.7 years). negatively correlated annul temperature, occurring about three years faster one degree increase indicating under warming climate. positively microbial activities (indicated nitrogen), highlighting importance communities regulating dynamics. Climate, types, origins, vegetation, variables explained 37% variations τ, as indicated SEM, property was most factor affecting τ. This finding challenged previous perception climate driving dynamics, drivers varied according zones. recognizing different predicting dynamics zones would improve our understanding reduce uncertainties regarding biogeochemical models ongoing change.