Wang Songhan, Ciais Philippe, Reich Peter B, Cescatti Alessandro, Ellsworth David S, Janssens Ivan A, Sardans Jordi, Luo Yiqi, Smith Nicholas G, Du Enzai, Tian Di, Jiang Yu, Ding Yanfeng, Peñuelas Josep
Jiangsu Collaborative Innovation Center for Modern Crop Production, Key Laboratory of Crop Physiology and Ecology in Southern China, College of Agriculture, Nanjing Agricultural University, Nanjing, China.
Laboratoire des Sciences du Climat et de l'Environnement, CEA CNRS UVSQ, Gif-sur-Yvette, France.
Nat Ecol Evol. 2025 Sep 2. doi: 10.1038/s41559-025-02842-0.
Global vegetation growth is thought to be limited by nitrogen (N) more than by other nutrients. Here we document a stronger phosphorus (P) limitation on global photosynthesis compared with N over the last four decades. On the basis of more than 80,000 field observations of foliar nutrients and a machine learning method, we generated a long-term global dataset of foliar N and P concentrations for the period 1980-2017. We show a larger declining rate of foliar P concentration (-0.80 ± 0.008% yr) than of N concentration (-0.31 ± 0.002% yr). This decline has led to an increase in terrestrial areas limited by foliar P and a widespread constraint on vegetation photosynthesis, more than 1.5 times stronger than the constraint by foliar N. The increasing trend in global photosynthesis over the past 4 decades has been reduced by approximately 17.2% and 6.7% as a result of the decline in foliar P and N, respectively. This stronger P limitation on global photosynthesis implies a weakening of terrestrial carbon sinks due to an emerging P constraint and calls for stricter strategies for reducing anthropogenic emissions to mitigate climatic warming.
全球植被生长被认为受氮（N）的限制比受其他养分的限制更大。然而，我们发现，在过去四十年中，全球光合作用受到的磷（P）限制比氮更强。基于超过80000次对叶片养分的实地观测以及一种机器学习方法，我们生成了1980 - 2017年期间长期的全球叶片氮和磷浓度数据集。我们发现，叶片磷浓度的下降速率（-0.80±0.008%/年）大于氮浓度的下降速率（-0.31±0.002%/年）。这种下降导致受叶片磷限制的陆地面积增加，对植被光合作用产生广泛限制，其强度比叶片氮限制的强度高出1.5倍以上。由于叶片磷和氮的下降，过去40年全球光合作用的增加趋势分别减少了约17.2%和6.7%。全球光合作用受到的这种更强的磷限制意味着，由于新出现的磷限制，陆地碳汇正在减弱，因此需要更严格的策略来减少人为排放，以缓解气候变暖。
