In terrestrial ecosystems, nitrogen (N) and phosphorus (P) have been considered as the most important limiting nutrients of aboveground plant production. P limitation, however, is usually assumed to occur mainly in the strongly weathered lowland tropical regions but rarely elsewhere. Here we report that such P limitation is more widespread and much stronger than previously estimated. In our global meta-analysis, almost half (46.2%) of 652 P-addition field experiments reveal a significant P limitation on aboveground plant production.

Globally, P additions increase aboveground plant production by 34.9% in natural terrestrial ecosystems, which is 7.0–15.9% higher than previously suggested. In croplands, in contrast, P additions increase aboveground plant production by only 13.9%, probably because of historical fertilizations. The magnitude of P limitation also differs among climate zones, regions, and is driven by climate, ecosystem properties, and fertilization regimes.

In addition to confirming that P limitation is widespread in tropical regions, our study demonstrates that P limitation often occurs in other regions. This suggests that previous studies have underestimated the importance of altered P supply on aboveground plant production in natural terrestrial ecosystems.

The results from this work have been published in Nature Communications, for further reading please refer to: https://doi.org/10.1038/s41467-020-14492-w.

Figure 1. Locations of the 652 experiments in which the effect of P addition on aboveground plant production was assessed.