caa a22 4500 52878224X 20200127030802.0 cr unu---uuuuu 180924e201806 xx s 000 0 eng 10.3929/ethz-b-000256239 doi 10.1111/nph.15123 doi (ETHRESEARCH)oai:www.research-collection.ethz.ch:20.500.11850/256239 Quantifying soil moisture impacts on light use efficiency across biomes [Elektronische Daten] [Benjamin Stocker, id_orcid 0000-0003-2697-9096, Jakob Zscheischler, Trevor F. Keenan, I. Colin Prentice, Josep Peñuelas, Sonia I. Seneviratne] New phytol. Open access ethresearch Terrestrial primary productivity and carbon cycle impacts of droughts are commonly quantified using vapour pressure deficit (VPD) data and remotely sensed greenness, without accounting for soil moisture. However, soil moisture limitation is known to strongly affect plant physiology. Here, we investigate light use efficiency, the ratio of gross primary productivity (GPP) to absorbed light. We derive its fractional reduction due to soil moisture (fLUE), separated from VPD and greenness changes, using artificial neural networks trained on eddy covariance data, multiple soil moisture datasets and remotely sensed greenness. This reveals substantial impacts of soil moisture alone that reduce GPP by up to 40% at sites located in sub‐humid, semi‐arid or arid regions. For sites in relatively moist climates, we find, paradoxically, a muted fLUE response to drying soil, but reduced fLUE under wet conditions. fLUE identifies substantial drought impacts that are not captured when relying solely on VPD and greenness changes and, when seasonally recurring, are missed by traditional, anomaly‐based drought indices. Counter to common assumptions, fLUE reductions are largest in drought‐deciduous vegetation, including grasslands. Our results highlight the necessity to account for soil moisture limitation in terrestrial primary productivity data products, especially for drought‐related assessments. Creative Commons Attribution 4.0 International http://creativecommons.org/licenses/by/4.0 ethresearch drought impacts ethresearch eddy covariance ethresearch gross primary productivity (GPP) ethresearch light use efficiency ethresearch photosynthesis ethresearch soil moisture ethresearch standardized precipitation index ethresearch vapour pressure deficit (VPD) ethresearch Stocker Benjamin joint author id_orcid 0000-0003-2697-9096 joint author Zscheischler Jakob joint author Keenan Trevor F. joint author Prentice I. Colin joint author Peñuelas Josep joint author Seneviratne Sonia I. joint author New Phytologist Oxford : Wiley-Blackwell 218 (4), pp. 1430-1449 0028-646X http://hdl.handle.net/20.500.11850/256239 text/html WWW-Backlink auf das Repository (Open access) 1 Journal Article ethresearch ETHRESEARCH 856 40 http://hdl.handle.net/20.500.11850/256239 text/html WWW-Backlink auf das Repository (Open access) ETHRESEARCH 700 1- Stocker Benjamin joint author ETHRESEARCH 700 -- id_orcid 0000-0003-2697-9096 joint author ETHRESEARCH 700 1- Zscheischler Jakob joint author ETHRESEARCH 700 1- Keenan Trevor F. joint author ETHRESEARCH 700 1- Prentice I. Colin joint author ETHRESEARCH 700 1- Peñuelas Josep joint author ETHRESEARCH 700 1- Seneviratne Sonia I. joint author ETHRESEARCH 773 0- New Phytologist Oxford : Wiley-Blackwell 218 (4), pp. 1430-1449 0028-646X BK010053 XK010053 XK010000 ETHRESEARCH ETHRESEARCH ETHRESEARCH Journal Article Open access