Afforestation promotes soil nitrous oxide production by ammonia oxidizers

The contribution of ammonia–oxidizing archaea (AOA), bacteria (AOB), and complete ammonia oxidizers (comammox) to nitrous oxide (N2O) production following afforestation remains poorly understood, hindering our ability to assess the sustainability of rehabilitated ecosystems. We investigated the factors influencing aerobic N2O in cropland and plantation forest soils in southwest China using molecular techniques and inhibitor experiments. Our findings reveal that afforestation significantly increased N2O production derived from AOA, AOB, and comammox. This increase can be attributed to enhanced N mineralization and ammonia availability, likely driven by elevated calcium concentration, alleviated phosphorus limitation, and aggravated microbial nitrogen limitation. Furthermore, we observed that N2O production was predominantly mediated by AOB at both land–use types, accounting for 42–47%, followed by AOA (34–37%). Comammox contributed 10–11% to total N2O production, with an N2O yield of approximately 0.04–0.22%. Such positive impacts of afforestation on ammonia oxidizers produced N2O should be fully considered when assessing afforestation's climate change mitigation outcomes and for the sustainability of ecosystems.造林后，氨氧化古菌（ammonia–oxidizing archaea, AOA）、氨氧化细菌（ammonia–oxidizing bacteria, AOB）以及完全氨氧化菌（complete ammonia oxidizers, comammox）对一氧化二氮（nitrous oxide, N2O）产生的贡献仍未得到充分阐明，这阻碍了我们评估修复后生态系统可持续性的能力。本研究针对中国西南地区农田与人工林土壤，采用分子技术与抑制剂实验，探究了好氧条件下一氧化二氮产生的影响因素。研究结果表明，造林显著提升了由AOA、AOB及comammox介导的一氧化二氮产生量。该提升可归因于氮矿化作用增强与氨有效性提升，这大概率由钙浓度升高、磷限制缓解以及微生物氮限制加剧所驱动。此外，我们观察到，在两种土地利用类型中，一氧化二氮的产生主要由AOB介导，占比达42%~47%，其次为AOA（34%~37%）。comammox对总一氧化二氮产生量的贡献为10%~11%，其N2O产率约为0.04%~0.22%。在评估造林的气候变化减缓成效以及生态系统可持续性时，应充分考虑造林对氨氧化菌产生一氧化二氮的这类积极影响。

搜集汇总

背景与挑战

背景概述

该数据集研究植树造林如何通过氨氧化剂促进土壤一氧化二氮生产，重点关注氨氧化古菌、细菌和完全氨氧化剂的贡献机制。研究在中国西南部进行，揭示植树造林增加钙浓度、缓解磷限制并加剧微生物氮限制，从而提升一氧化二氮产量。数据集属于环境科学领域，数据量较小，适用于评估植树造林对气候变化和生态系统可持续性的影响。