Plants can be classified as either resource-acquisitive or resource-conservative strategies based on a suite of root functional traits. Compared with conservative trees, resource-acquisitive trees can produce larger amounts of readily decomposable carbon, owing to their high specific root length (SRL) and low root C:N ratio, which would reduce the content and stability of soil organic carbon (SOC). In this study, we assessed the content of labile particulate organic carbon (POC) and stable mineral-associated organic carbon (MAOC) in the rhizosphere and bulk soils of acquisitive and conservative trees in a subtropical forest. Contrary to our expectations, we found that SOC content in the rhizosphere soil of acquisitive trees (26 g kg^-1) was 53% higher than that in the rhizosphere soil of conservative trees (17 g kg^-1), which was mainly attributed to an approximately 1-fold higher MAOC content. Correlation and structural equation modeling analyses indicated that this rhizosphere MAOC was primarily derived from root and mainly stimulated by high SRL, rhizosphere soil microbial biomass C, and enzyme C:N ratio, whereas the POC was mainly derived from aboveground litter. We further found that the contrasting plant strategies had no significant influence on the POC content of bulk or rhizosphere soil, which could be ascribed to the similar properties of aboveground litter of acquisitive and conservative trees. These findings indicate that acquisitive trees enhance rhizosphere soil C stability primarily via the mediation of root traits and highlight the necessity of considering plant ecological strategies when assessing the effects of tree species on soil C content and stability.

根据一套根功能性状，植物可以分为资源获取策略或资源节约策略。与保守树木相比，资源获取型树木由于其高比根长（SRL）和低根C:N比​​，可以产生大量易分解的碳，这会降低土壤有机碳（SOC）的含量和稳定性. 在这项研究中，我们评估了亚热带森林中获取性和保守性树木的根际和大块土壤中不稳定颗粒有机碳 (POC) 和稳定矿物相关有机碳 (MAOC) 的含量。与我们的预期相反，我们发现获得性树木根际土壤中的 SOC 含量 (26 g kg ^-1) 比保守树根际土壤 (17 g kg ^-1)，这主要归因于 MAOC 含量高出约 1 倍。相关性和结构方程模型分析表明，该根际 MAOC 主要来源于根，主要受到高 SRL、根际土壤微生物生物量 C 和酶 C:N 比的刺激，而 POC 主要来源于地上凋落物。我们进一步发现，对比植物策略对大块或根际土壤的 POC 含量没有显着影响，这可以归因于获得性和保守性树木地上凋落物的相似特性。