Mixed afforestation alters soil carbon pool accumulation and stability by influencing aggregate mass proportion

This dataset contains soil physical, chemical, and biological measurements from three Pinus massoniana forest types in subtropical China: pure plantation (MPF), conifer-conifer mixed (MCLMF), and conifer-broadleaf mixed (MLMF). It includes aggregate mass distribution (four size classes), concentrations of soil organic carbon (SOC) fractions (e.g., POC, MBC, LOC, NC333), and key soil properties (texture, nitrogen, pH, etc.). Notable findings show that micro-aggregates hold higher carbon concentrations than macro-aggregates. Mixed afforestation had divergent effects: MCLMF increased SOC and stable carbon (NC333) storage, while MLMF decreased it. Both mixtures enhanced carbon stability by increasing the NC333 proportion. The shift in aggregate mass ratio and associated microbial activity (MBC) were key drivers of post-afforestation carbon dynamics. Data was gathered via soil sampling, wet-sieving for aggregates, and standard lab protocols for carbon fractionation. This dataset is valuable for verifying forest management impacts on soil carbon, supporting meta-analyses, calibrating models, and investigating specific mechanisms like nitrogen-aggregate-carbon interactions.本数据集涵盖中国亚热带地区三种马尾松(Pinus massoniana)林分的土壤物理、化学与生物学测定数据，分别为纯人工林(MPF)、针叶-针叶混交林(MCLMF)以及针叶-阔叶混交林(MLMF)。数据集包含土壤团聚体质量分布（共4个粒径等级）、土壤有机碳(Soil Organic Carbon, SOC)组分浓度（如颗粒态有机碳(Particulate Organic Carbon, POC)、微生物生物量碳(Microbial Biomass Carbon, MBC)、溶解性有机碳(Dissolved Organic Carbon, LOC)以及NC333）以及核心土壤理化性质（土壤质地、全氮、pH值等）。核心研究发现表明，微团聚体的碳浓度显著高于大团聚体。混交造林的生态效应存在分化：MCLMF可提升SOC与稳定性碳(NC333)储量，而MLMF则会降低该储量。两种混交林分均通过提升NC333占比增强了土壤碳稳定性。团聚体质量占比的变化与相关微生物活性（MBC）是造林后土壤碳动态变化的核心驱动因子。数据通过土壤采样、湿筛法分离团聚体以及碳组分分级的标准实验室流程采集获得。本数据集可用于验证森林经营措施对土壤碳库的影响、支撑荟萃分析、模型校准，以及探究氮-团聚体-碳互作等特定作用机制。