Data from: Microbial regulation of particulate organic carbon dominates soil carbon responses to warming in alpine meadow soils

Soil organic carbon (SOC) storage and stability are recognized to be significantly influenced by changes in particulate organic carbon (POC) and mineral-associated organic carbon (MAOC). However, the effects of warming on POC, MAOC, and SOC, along with the underlying microbial mechanisms, remain poorly understood. In this study, we utilized data from a 6-year, multi-level soil warming experiment (+0°C, +0.9°C, +1.7°C, and +2.9°C) conducted in an alpine grassland to investigate these effects. Warming altered the SOC composition without changing its total content. Specifically, warming increased topsoil POC content by 9.3%-22.2%, while decreased MAOC content by 10.3%-27.0%. Subsoil MAOC content exhibited a nonlinear concave trend as the warming gradient increased. Notably, SOC dynamics along soil profile were mainly driven by POC rather than MAOC. Topsoil POC increases were attributed to increases in soil dissolved organic carbon, available phosphorus, microbial biomass carbon (MBC), and nccromass carbon (MNC), whereas subsoil POC remained relatively stable due to persistence MNC and a nonlinear convex response of MBC to warming. These results underscore the role of MNC in improving POC pool and highlight the insufficiency of relying solely on increasing MAOC to promote SOC accumulation. Instead, SOC enhancement strategies in alpine meadows should explicitly balance POC-driven increases against potential long-term stability losses.