Afforestation mitigates soil nitrogen limitation by enhancing mineralization and lowering denitrification in central China

Afforestation has profoundly altered soil nitrogen (N) transformation, particularly the key processes governing soil organic N and inorganic N dynamics, which determine soil N availability. However, the divergences in soil N transformation and the main influencing factors following different afforestation types have not been systematically clarified. Here, we examined soil net N mineralization rate (NMR), net nitrification rate (NNR), and potential denitrification rate (PDR) at 144 paired sampling sites by comparing different afforestation types (initial land use types and tree species) in central China. Afforestation significantly enhanced soil NMR, but lowered NNR and PDR, respectively, compared to non-afforested lands. Soil NMR and PDR responses to afforestation from cropland were more sensitive than those from shrubland. Notably, broadleaf afforestation (i.e., Quercus variabilis) had a stronger effect on altering NMR compared to coniferous afforestation (i.e., Platycladus orientalis..., , # Dataset title: Afforestation mitigates soil nitrogen limitation by enhancing mineralization and lowering denitrification in central China DOI: [https://doi.org/10.5061/dryad.m37pvmdhc](https://doi.org/10.5061/dryad.m37pvmdhc) ## Description of the data and file structure ### **Data Description** This dataset contains measurements of **soil nitrogen transformation rates**, soil physicochemical properties, and microbial characteristics collected from **central China**. The study aimed to assess how **different afforestation types influence soil nitrogen (N) cycling processes**, particularly those governing soil N availability. **Experimental Efforts:** * **Sample Collection**: During October to November 2021, paired sampling surveys were conducted across four subbasins in central China. Non-afforested lands (i.e., cropland or shrubland) were paired with adjacent afforested lands dominated by coniferous trees (*Platycladus orientalis*, *Pinus massoniana*) and broad-leaved trees (*Q..., ,造林已深刻改变土壤氮（N）转化过程，尤其是调控土壤有机氮与无机氮动态的核心过程——此类过程直接决定土壤氮素有效性。然而，不同造林类型下土壤氮转化的差异及其主要影响因素尚未得到系统阐明。本研究于中国中部地区的144对样点中，通过对比不同造林类型（包括初始土地利用类型与树种），测定了土壤净氮矿化速率（soil net N mineralization rate, NMR）、净硝化速率（net nitrification rate, NNR）与潜在反硝化速率（potential denitrification rate, PDR）。与非造林地相比，造林显著提升了土壤净氮矿化速率，却分别降低了净硝化速率与潜在反硝化速率。相较于源自灌丛的造林样地，源自农田的造林样地的土壤净氮矿化速率与潜在反硝化速率对造林的响应更为敏感。值得注意的是，阔叶造林（如栓皮栎*Quercus variabilis*）对土壤净氮矿化速率的调控效应强于针叶造林（如侧柏*Platycladus orientalis*）。 # 数据集标题：中国中部地区造林通过提升矿化作用、降低反硝化作用缓解土壤氮限制 DOI: [https://doi.org/10.5061/dryad.m37pvmdhc](https://doi.org/10.5061/dryad.m37pvmdhc) ## 数据与文件结构说明 ### **数据说明** 本数据集包含在中国中部地区采集的**土壤氮转化速率**、土壤理化性质与微生物特性的测定数据。本研究旨在评估**不同造林类型对土壤氮（N）循环过程的调控效应**，尤其是决定土壤氮素有效性的相关过程。 **实验工作：** * **样品采集**：2021年10月至11月，研究团队在中国中部的四个子流域开展配对采样调查。以相邻的非造林地（即农田或灌丛）为对照，配对比较了以针叶树（侧柏*Platycladus orientalis*、马尾松*Pinus massoniana*）和阔叶树（*Q*...）为优势种的造林地。