Soil organic carbon (SOC) persistence is predominantly governed by mineral protection, consequently, soil mineral-associated (MAOC) and particulate organic carbon (POC) turnovers have different impacts on the vulnerability of SOC to climate change. Here, we generate the global MAOC and POC maps using 8341 observations and then infer the turnover times of MAOC and POC by a data-model integration approach. Global MAOC and POC storages are $${975}_{964}^{987}$$975 964 987 Pg C (mean with 5% and 95% quantiles) and $${330}_{323}^{337}$$330 323 337 Pg C, while global mean MAOC and POC turnover times are $${129}_{45}^{383}$$129 45 383 yr and $${23}_{5}^{82}$$23 5 82 yr in the top meter, respectively. Climate warming-induced acceleration of MAOC and POC decomposition is greater in subsoil than that in topsoil. Overall, the global atlas of MAOC and POC turnover, together with the global distributions of MAOC and POC stocks, provide a benchmark for Earth system models to diagnose SOC-climate change feedback.

Understanding the large-scale pattern of soil microbial carbon use efficiency (CUE) and its temperature sensitivity (CUE_T) is critical for understanding soil carbon–climate feedback. We used the¹⁸O-H₂O tracer method to quantify CUE and CUE_Talong a north-south forest transect. Climate was the primary factor that affected CUE and CUE_T, predominantly through direct pathways, then by altering soil properties, carbon fractions, microbial structure and functions. Negative CUE_T(CUE decreases with measuring temperature) in cold forests (mean annual temperature lower than 10 °C) and positive CUE_T(CUE increases with measuring temperature) in warm forests (mean annual temperature greater than 10 °C) suggest that microbial CUE optimally operates at their adapted temperature. Overall, the plasticity of microbial CUE and its temperature sensitivity alter the feedback of soil carbon to climate warming; that is, a climate-adaptive microbial community has the capacity to reduce carbon loss from soil matrices under corresponding favorable climate conditions.

Soil microbial growth, a vital biogeochemical process, governs both the accrual and loss of soil carbon. Here, we investigate the biogeography of soil microbiome potential growth rates and show that microbiomes in resource-rich (high organic matter and nutrients) and acid-neutral soils from cold and humid regions exhibit high potential growth. Conversely, in resource-poor, dry, hot, and hypersaline soils, soil microbiomes display lower potential growth rates, suggesting trade-offs between growth and resource acquisition or stress tolerance. In addition, the potential growth rates of soil microbiomes positively correlates with genome size and the number of ribosomal RNA operons but negatively correlates with optimum temperature, biomass carbon-to-phosphorus and nitrogen-to-phosphorus ratios. The spatial variation of microbial potential growth rates aligns with several macroecological theories. These findings not only enhance our understanding of microbial adaptation to diverse environments but also aid in realistically parameterizing microbial physiology in soil carbon cycling models.

Plant nitrogen (N) and phosphorus (P) resorption is an important strategy to conserve N and P in the face of nutrient limitation. However, little is known about the variation of N and P resorption efficiency (NRE and PRE) and their correlation with leaves and soil C:N:P stoichiometry in black locust forests (Robinia pseudoacacia L.) of different ages. In this study, we measured C, N, and P concentrations in soil, green leaves, and senesced leaves from black locust forests of different ages (i.e, 10-, 20-, 30-, 36-, and 45-year-old), and calculated the NRE, PRE, and C:N:P stoichiometry ratios. The NRE and PRE tended to increase and then decrease with stand age, ranging from 46.8% to 57.4% and from 37.4% to 58.5%, with averages of 52.61 and 51.89, respectively. The PRE:NRE decreased with increased stand ages. The C:P and N:P of soil and green leaves increased with stand ages, indicating the increase of P limitation. In the senesced leaves, C:P and N:P were lower than in green leaves and first increased and then decreased with stand age. The PRE was significantly negatively correlated with the C:P and N:P of soil and green leaves. The NRE was significantly correlated with the C concentration of green leaves, P of the senesced leaves, and C:N. Results suggested that the NRE and PRE responded differently to soil and plant nutrients in black locust forests of different ages. In addition, the black locust plantations would alter the conservation and use strategy of nutrients in the ecosystem through a plant-mediated pathway. Future studies should elucidate the central nutrient utilization strategy of black locust in response to a nutrient-poor environment and determine how it is involved in regulating nutrient resorption.