Zuo Hanling, Xiao Wensheng, Dong Mingqiu, Gu Xinyun, Liang Xia, Smith Pete, Baquerizo Manuel Delgado, Hou Lijun, Zhou Xiaoqi
Zhejiang Tiantong Forest Ecosystem National Observation and Research Station, Zhejiang Zhoushan Island Ecosystem Observation and Research Station, Institute of Eco-Chongming, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China.
State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200241, China.
Natl Sci Rev. 2025 May 13;12(7):nwaf186. doi: 10.1093/nsr/nwaf186. eCollection 2025 Jul.
Forests are recognized as the largest natural source of nitrous oxide (NO) emissions on land, with deforestation drastically reducing the cover and biodiversity of native forests worldwide. Yet, how losses in forest biodiversity affect soil NO fluxes remains poorly understood. Here, we combined a global tree diversity-forest soil NO data set, including 201 paired comparable observations from global forests, with a three-year field survey of flux data gathered from a long-term plant diversity field experiment. Our analyses reveal that tree diversity has a significant negative effect on soil NO emissions, primarily driven by a decrease in NO production associated with denitrification. More specifically, we showed that reductions in NO emissions with tree diversity can be attributed to a decrease in the availability of soil inorganic nitrogen. Predictive modeling further shows that compared to forests with a single tree species, forests with two tree species can reduce global forest NO emissions by 10.39%, while those with 24 tree species achieve the maximum mitigation effect, reducing emissions by 56.30%. Taken together, our work highlights the contribution of tree diversity for mitigating NO emissions, highlighting the importance of accounting for biodiversity when reforesting old forests and supporting new afforestation processes.
森林被认为是陆地上一氧化二氮（N₂O）排放的最大自然来源，森林砍伐极大地减少了全球原生森林的覆盖面积和生物多样性。然而，森林生物多样性的丧失如何影响土壤N₂O通量仍知之甚少。在这里，我们将一个全球树木多样性-森林土壤N₂O数据集（包括来自全球森林的201对可比观测数据）与一项为期三年的实地调查相结合，该调查收集了来自长期植物多样性田间试验的通量数据。我们的分析表明，树木多样性对土壤N₂O排放有显著的负面影响，主要是由与反硝化作用相关的N₂O产生减少所驱动。更具体地说，我们表明，随着树木多样性增加N₂O排放减少可归因于土壤无机氮有效性的降低。预测模型进一步表明，与单一树种的森林相比，两种树种的森林可使全球森林N₂O排放减少10.39%，而拥有24种树种的森林实现最大缓解效果，减排56.30%。综上所述，我们的工作突出了树木多样性对减轻N₂O排放的贡献，强调了在对老龄森林进行重新造林和支持新的造林过程时考虑生物多样性的重要性。
