Atmospheric Dryness Dominates Afternoon Depression of Global Terrestrial Photosynthesis
Liu, Yue (Nanjing University)
Peñuelas, Josep (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Cescatti, Alessandro (Joint Research Centre)
Zhang, Yongguang (Nanjing University)
Zhang, Zhaoying (Nanjing University)

Date:	2024
Abstract:	Satellite observations reveal a widespread afternoon depression of photosynthesis globally. Utilizing satellite observations and eddy covariance tower-based observations worldwide, we investigated the impact of climate factors on the diurnal patterns of ecosystem gross primary production (GPP). Our analysis revealed that the increase in vapor pressure deficit (VPD) shifts the diurnal peak of GPP activity to earlier morning hours, particularly in drylands and areas with short vegetation. After disentangling the strong correlations among VPD, temperature, and soil moisture, we unraveled that VPD emerges as the dominant driver contributing to the widespread afternoon depression of photosynthesis in terrestrial vegetation globally. However, Earth System Models (ESMs) systematically underestimate the significant role of VPD in regulating photosynthesis. Eight out of 10 ESMs exhibited a clear afternoon increase in photosynthesis, which was attributed to temperature. Our findings emphasize the need to enhance the negative effects of VPD on diurnal photosynthesis in ESMs.
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, i la comunicació pública de l'obra, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original. No es permet la creació d'obres derivades.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Published in:	Geophysical Research Letters, Vol 51, Issue 24 (December 2024) , art. e2024GL110954, ISSN 1944-8007

DOI: 10.1029/2024GL110954

12 p, 3.7 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
Articles > Published articles