Nitrogen addition delays the emergence of an aridity-induced threshold for plant biomass
Li, Hailing (Lanzhou University. College of Ecology. State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems)
Terrer, César (Massachusetts Institute of Technology. Department of Civil and Environmental Engineering)
Berdugo, Miguel (Universitat d'Alacant. Institut Multidisciplinari per a l'Estudi del Medi 'Ramón Margalef')
Maestre, Fernando T. (Universitat d'Alacant. Institut Multidisciplinari per a l'Estudi del Medi 'Ramón Margalef')
Zhu, Zaichun (Peking University. School of Urban Planning and Design)
Peñuelas, Josep (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Yu, Kailiang (Princeton University. High Meadows Environmental Institute)
Luo, Lin (Lanzhou University. College of Ecology. State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems)
Gong, Jie-Yu (Lanzhou University. College of Ecology. State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems)
Ye, Jian-Sheng (Lanzhou University. College of Ecology. State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems)

Date:	2023
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.
Grants:	Agencia Estatal de Investigación TED2021-132627B-I00 Ministerio de Ciencia e Innovación EUR2022-134048 Agència de Gestió d'Ajuts Universitaris i de Recerca 2021/SGR-1333
Note:	Altres ajuts: J.P. is supported by the Fundación Ramón Areces grant CIVP20A6621.
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Aboveground biomass ; Root:shoot ratios ; Elevated CO2 ; Nitrogen fertilization ; Ecosystem threshold
Published in:	National science review, Vol. 10, issue 11 (Nov. 2023) , art. nwad242, ISSN 2053-714X

DOI: 10.1093/nsr/nwad242
PMID: 37900195

12 p, 3.1 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > CREAF (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Articles > Research articles
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