Nitrogen addition delays the emergence of an aridity-induced threshold for plant biomass

Hailing Li, César Terrer, Miguel Berdugo, Fernando T. Maestre, Zaichun Zhu, Josep Peñuelas, Kailiang Yu, Lin Luo, Jie Yu Gong, Jian Sheng Ye*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

1 Scopus citations

Abstract

Crossing certain aridity thresholds in global drylands can lead to abrupt decays of ecosystem attributes such as plant productivity, potentially causing land degradation and desertification. It is largely unknown, however, whether these thresholds can be altered by other key global change drivers known to affect the water-use efficiency and productivity of vegetation, such as elevated CO2 and nitrogen (N). Using >5000 empirical measurements of plant biomass, we showed that crossing an aridity (1–precipitation/potential evapotranspiration) threshold of ∼0.50, which marks the transition from dry sub-humid to semi-arid climates, led to abrupt declines in aboveground biomass (AGB) and progressive increases in root:shoot ratios, thus importantly affecting carbon stocks and their distribution. N addition significantly increased AGB and delayed the emergence of its aridity threshold from 0.49 to 0.55 (P < 0.05). By coupling remote sensing estimates of leaf area index with simulations from multiple models, we found that CO2 enrichment did not alter the observed aridity threshold. By 2100, and under the RCP 8.5 scenario, we forecast a 0.3% net increase in the global land area exceeding the aridity threshold detected under a scenario that includes N deposition, in comparison to a 2.9% net increase if the N effect is not considered. Our study thus indicates that N addition could mitigate to a great extent the negative impact of increasing aridity on plant biomass in drylands. These findings are critical for improving forecasts of abrupt vegetation changes in response to ongoing global environmental change.

Original languageEnglish (US)
Article numbernwad242
JournalNational Science Review
Volume10
Issue number11
DOIs
StatePublished - Nov 1 2023

Keywords

  • aboveground biomass
  • ecosystem threshold
  • elevated CO
  • nitrogen fertilization
  • root:shoot ratios

ASJC Scopus subject areas

  • General

Fingerprint

Dive into the research topics of 'Nitrogen addition delays the emergence of an aridity-induced threshold for plant biomass'. Together they form a unique fingerprint.

Cite this