CO2 fertilization is spatially distinct from stomatal conductance reduction in controlling ecosystem water-use efficiency increase
It is well known that global ecosystem water-use efficiency (EWUE) has noticeably increased over the last several decades. However, it remains unclear how individual environmental drivers contribute to EWUE changes, particularly from CO _2 fertilization and stomatal suppression effects. Using a sate...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2022-01-01
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| Series: | Environmental Research Letters |
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| Online Access: | https://doi.org/10.1088/1748-9326/ac6c9c |
| _version_ | 1797746919489929216 |
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| author | Xuanze Zhang Yongqiang Zhang Jing Tian Ning Ma Ying-Ping Wang |
| author_facet | Xuanze Zhang Yongqiang Zhang Jing Tian Ning Ma Ying-Ping Wang |
| author_sort | Xuanze Zhang |
| collection | DOAJ |
| description | It is well known that global ecosystem water-use efficiency (EWUE) has noticeably increased over the last several decades. However, it remains unclear how individual environmental drivers contribute to EWUE changes, particularly from CO _2 fertilization and stomatal suppression effects. Using a satellite-driven water–carbon coupling model—Penman–Monteith–Leuning version 2 (PML-V2), we quantified individual contributions from the observational drivers (atmospheric CO _2 , climate forcing, leaf area index (LAI), albedo and emissivity) across the globe over 1982–2014. The PML-V2 was well-calibrated and showed a good performance for simulating EWUE (with a determination coefficient ( R ^2 ) of 0.56) compared to observational annual EWUE over 1982–2014 derived from global 95 eddy flux sites from the FLUXNET2015 dataset. Our results showed that global EWUE increasing trend (0.04 ± 0.004 gC mm ^−1 H _2 O decade ^−1 ) was largely contributed by increasing CO _2 (51%) and LAI (20%), but counteracted by climate forcing (−26%). Globally, the CO _2 fertilization effect on photosynthesis (23%) was similar to the CO _2 suppression effect on stomatal conductance (28%). Spatially, the fertilization effect dominated EWUE trend over semi-arid regions while the stomatal suppression effect controlled over tropical forests. These findings improve understanding of how environmental factors affect the long-term change of EWUE, and can help policymakers for water use planning and ecosystem management. |
| first_indexed | 2024-03-12T15:44:39Z |
| format | Article |
| id | doaj.art-0756be486c0a45d6827d814c62652e13 |
| institution | Directory Open Access Journal |
| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-03-12T15:44:39Z |
| publishDate | 2022-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj.art-0756be486c0a45d6827d814c62652e132023-08-09T15:30:44ZengIOP PublishingEnvironmental Research Letters1748-93262022-01-0117505404810.1088/1748-9326/ac6c9cCO2 fertilization is spatially distinct from stomatal conductance reduction in controlling ecosystem water-use efficiency increaseXuanze Zhang0https://orcid.org/0000-0001-8515-5084Yongqiang Zhang1https://orcid.org/0000-0002-3562-2323Jing Tian2Ning Ma3https://orcid.org/0000-0003-4580-0661Ying-Ping Wang4Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences , Beijing 100101, People’s Republic of ChinaKey Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences , Beijing 100101, People’s Republic of ChinaKey Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences , Beijing 100101, People’s Republic of ChinaKey Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences , Beijing 100101, People’s Republic of ChinaTerrestrial Biogeochemistry Group, South China Botanical Garden, Chinese Academy of Sciences , Guangzhou 510650, People’s Republic of China; CSIRO Oceans and Atmosphere , Private Bag 1, Aspendale, Victoria 3195, AustraliaIt is well known that global ecosystem water-use efficiency (EWUE) has noticeably increased over the last several decades. However, it remains unclear how individual environmental drivers contribute to EWUE changes, particularly from CO _2 fertilization and stomatal suppression effects. Using a satellite-driven water–carbon coupling model—Penman–Monteith–Leuning version 2 (PML-V2), we quantified individual contributions from the observational drivers (atmospheric CO _2 , climate forcing, leaf area index (LAI), albedo and emissivity) across the globe over 1982–2014. The PML-V2 was well-calibrated and showed a good performance for simulating EWUE (with a determination coefficient ( R ^2 ) of 0.56) compared to observational annual EWUE over 1982–2014 derived from global 95 eddy flux sites from the FLUXNET2015 dataset. Our results showed that global EWUE increasing trend (0.04 ± 0.004 gC mm ^−1 H _2 O decade ^−1 ) was largely contributed by increasing CO _2 (51%) and LAI (20%), but counteracted by climate forcing (−26%). Globally, the CO _2 fertilization effect on photosynthesis (23%) was similar to the CO _2 suppression effect on stomatal conductance (28%). Spatially, the fertilization effect dominated EWUE trend over semi-arid regions while the stomatal suppression effect controlled over tropical forests. These findings improve understanding of how environmental factors affect the long-term change of EWUE, and can help policymakers for water use planning and ecosystem management.https://doi.org/10.1088/1748-9326/ac6c9cecosystem water-use efficiencyCO2 fertilizationstomatal conductanceclimate changeearth greening |
| spellingShingle | Xuanze Zhang Yongqiang Zhang Jing Tian Ning Ma Ying-Ping Wang CO2 fertilization is spatially distinct from stomatal conductance reduction in controlling ecosystem water-use efficiency increase Environmental Research Letters ecosystem water-use efficiency CO2 fertilization stomatal conductance climate change earth greening |
| title | CO2 fertilization is spatially distinct from stomatal conductance reduction in controlling ecosystem water-use efficiency increase |
| title_full | CO2 fertilization is spatially distinct from stomatal conductance reduction in controlling ecosystem water-use efficiency increase |
| title_fullStr | CO2 fertilization is spatially distinct from stomatal conductance reduction in controlling ecosystem water-use efficiency increase |
| title_full_unstemmed | CO2 fertilization is spatially distinct from stomatal conductance reduction in controlling ecosystem water-use efficiency increase |
| title_short | CO2 fertilization is spatially distinct from stomatal conductance reduction in controlling ecosystem water-use efficiency increase |
| title_sort | co2 fertilization is spatially distinct from stomatal conductance reduction in controlling ecosystem water use efficiency increase |
| topic | ecosystem water-use efficiency CO2 fertilization stomatal conductance climate change earth greening |
| url | https://doi.org/10.1088/1748-9326/ac6c9c |
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