The opening and closing of plant stomata regulates the global water, carbon and energy cycles. Biophysical feedbacks on climate are highly dependent on transpiration, which is mediated by vegetation phenology and plant responses to stress conditions. Here, we explore the potential of satellite observations of solar-induced chlorophyll fluorescence (SIF)\uffe2\uff80\uff94normalized by photosynthetically-active radiation (PAR)\uffe2\uff80\uff94to diagnose the ratio of transpiration to potential evaporation (\uffe2\uff80\uff98transpiration efficiency\uffe2\uff80\uff99, \uffcf\uff84). This potential is validated at 25 eddy-covariance sites from seven biomes worldwide. The skill of the state-of-the-art land surface models (LSMs) from the eartH2Observe project to estimate \uffcf\uff84 is also contrasted against eddy-covariance data. Despite its relatively coarse (0.5\uffc2\uffb0) resolution, SIF/PAR estimates, based on data from the Global Ozone Monitoring Experiment 2 (GOME-2) and the Clouds and Earth\uffe2\uff80\uff99s Radiant Energy System (CERES), correlate to the in situ \uffcf\uff84 significantly (average inter-site correlation of 0.59), with higher correlations during growing seasons (0.64) compared to decaying periods (0.53). In addition, the skill to diagnose the variability of in situ \uffcf\uff84 demonstrated by all LSMs is on average lower, indicating the potential of SIF data to constrain the formulations of transpiration in global models via, e.g., data assimilation. Overall, SIF/PAR estimates successfully capture the effect of phenological changes and environmental stress on natural ecosystem transpiration, adequately reflecting the timing of this variability without complex parameterizations.
", "keywords": ["VEGETATION DYNAMICS", "Science", "STOMATAL CONDUCTANCE", "0207 environmental engineering", "solar-induced chlorophyll fluorescence", "02 engineering and technology", "01 natural sciences", "transpiration", "CARBON", "GOME-2", "WATER", "PLANT", "0105 earth and related environmental sciences", "EVAPOTRANSPIRATION", "Q", "Biology and Life Sciences", "15. Life on land", "MODEL", "EVAPORATION", "SOIL", "PARTITIONING", "transpiration efficiency", "efficiency", "13. Climate action", "Earth and Environmental Sciences", "INDUCED CHLOROPHYLL FLUORESCENCE", "solar-induced chlorophyll fluorescence; transpiration; transpiration efficiency; GOME-2; eddy-covariance", "eddy-covariance"]}, "links": [{"href": "http://www.mdpi.com/2072-4292/11/4/413/pdf"}, {"href": "https://doi.org/10.3390/rs11040413"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Remote%20Sensing", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.3390/rs11040413", "name": "item", "description": "10.3390/rs11040413", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.3390/rs11040413"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2019-02-18T00:00:00Z"}}, {"id": "10.1111/gcb.14815", "type": "Feature", "geometry": null, "properties": {"updated": "2026-04-13T16:19:22Z", "type": "Journal Article", "created": "2019-08-30", "title": "How to measure, report and verify soil carbon change to realize the potential of soil carbon sequestration for atmospheric greenhouse gas removal", "description": "AbstractThere is growing international interest in better managing soils to increase soil organic carbon (SOC) content to contribute to climate change mitigation, to enhance resilience to climate change and to underpin food security, through initiatives such as international \uffe2\uff80\uff984p1000\uffe2\uff80\uff99 initiative and the FAO's Global assessment of SOC sequestration potential (GSOCseq) programme. Since SOC content of soils cannot be easily measured, a key barrier to implementing programmes to increase SOC at large scale, is the need for credible and reliable measurement/monitoring, reporting and verification (MRV) platforms, both for national reporting and for emissions trading. Without such platforms, investments could be considered risky. In this paper, we review methods and challenges of measuring SOC change directly in soils, before examining some recent novel developments that show promise for quantifying SOC. We describe how repeat soil surveys are used to estimate changes in SOC over time, and how long\uffe2\uff80\uff90term experiments and space\uffe2\uff80\uff90for\uffe2\uff80\uff90time substitution sites can serve as sources of knowledge and can be used to test models, and as potential benchmark sites in global frameworks to estimate SOC change. We briefly consider models that can be used to simulate and project change in SOC and examine the MRV platforms for SOC change already in use in various countries/regions. In the final section, we bring together the various components described in this review, to describe a new vision for a global framework for MRV of SOC change, to support national and international initiatives seeking to effect change in the way we manage our soils.Our objective was to test how a long\uffe2\uff80\uff90term increased water limitation affects structural and functional properties of a Mediterranean ecosystem, and how these changes modify the response of the main carbon fluxes to climatic controls. In 2003, a 27% throughfall exclusion experiment was installed in a Quercus ilex L. forest in France. Gross primary production (GPP), ecosystem respiration (RECO) and net ecosystem exchange (NEE) were estimated in a control and a dry treatment. Decreasing throughfall decreased GPP by 14% and had a smaller effect on RECO (\uffe2\uff88\uff9212%), especially soil respiration RS (\uffe2\uff88\uff9211%). Interannual variability of GPP (29%) was higher than for RECO (12%). Error propagation was used to estimates uncertainties in the NEE fluxes, which ranged from 3% to 10% in the control treatment but up to 167% for NEE in the dry treatment because more steps and data types were involved in the scaling. After 3 years of throughfall exclusion, we found no acclimation of RS to climatic drivers. Functional properties of the response of RS to soil water, temperature and rain pulse remained similar in the control and the dry treatments. A diurnal clockwise hysteresis in RS was probably controlled by canopy photosynthesis with a 3\uffe2\uff80\uff83h lag. The proportion of diurnal variation of respiration due to photosynthesis was similar in all treatments (4\uffe2\uff80\uff935%). Because of the characteristic of rain in Mediterranean climates, a continuous decrease of water input in these environments have an effect on topsoil water and consequently on RS only during short periods when rainfall is characterized by infrequent and small events that does not allow the topsoil to reach field capacity and does not allow to dry completely. However, in the longer term, we expect a stronger decrease in RS in the dry treatment driven by the decrease in GPP.
", "keywords": ["0106 biological sciences", "550", "15. Life on land", "gross primary production", "soil respiration", "01 natural sciences", "630", "6. Clean water", "Quercus ilex", "throughfall exclusion", "13. Climate action", "rain pulse", "eddy-covariance", "Q(10)", "error propagation", "0105 earth and related environmental sciences"]}, "links": [{"href": "https://doi.org/10.1111/j.1365-2486.2009.02121.x"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Global%20Change%20Biology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1111/j.1365-2486.2009.02121.x", "name": "item", "description": "10.1111/j.1365-2486.2009.02121.x", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1111/j.1365-2486.2009.02121.x"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2010-08-01T00:00:00Z"}}, {"id": "10.5194/hess-22-4513-2018", "type": "Feature", "geometry": null, "properties": {"updated": "2026-04-13T16:22:57Z", "type": "Journal Article", "created": "2018-08-27", "title": "Exploring the merging of the global land evaporation WACMOS-ET products based on local tower measurements", "description": "Abstract. An inverse error variance weighting of the anomalies of three terrestrial evaporation (ET) products from the WACMOS-ET project based on FLUXNET sites is presented. The three ET models were run daily and at a resolution of 25\uffe2\uff80\uff89km for 2002\uffe2\uff80\uff932007, and based on common input data when possible. The local weights, derived based on the variance of the difference between the tower ET anomalies and the modelled ET anomalies, were made dynamic by estimating them using a 61-day running window centred on each day. These were then extrapolated from the tower locations to the global landscape by regressing them on the main model inputs and derived ET using a neural network. Over the stations, the weighted scheme usefully decreased the random error component, and the weighted ET correlated better with the tower data than a simple average. The global extrapolation produced weights displaying strong seasonal and geographical patterns, which translated into spatiotemporal differences between the ET weighted and simple average ET products. However, the uncertainty of the weights after the extrapolation remained large. Out-sample prediction tests showed that the tower data set, mostly located at temperate regions, had limitations with respect to the representation of different biome and climate conditions. Therefore, even if the local weighting was successful, the extrapolation to a global scale remains problematic, showing a limited added value over the simple average. Overall, this study suggests that merging tower observations and ET products at the timescales and spatial scales of this study is complicated by the tower spatial representativeness, the products' coarse spatial resolution, the nature of the error in both towers and gridded data sets, and how all these factors impact the weights extrapolation from the tower locations to the global landscape.
", "keywords": ["Technology", "550", "SPATIAL VARIABILITY", "0207 environmental engineering", "FLUX MEASUREMENTS", "02 engineering and technology", "SOIL-MOISTURE", "Environmental technology. Sanitary engineering", "01 natural sciences", "[PHYS] Physics [physics]", "G", "ENERGY-BALANCE CLOSURE", "Geography. Anthropology. Recreation", "GE1-350", "TD1-1066", "0105 earth and related environmental sciences", "[PHYS]Physics [physics]", "EVAPOTRANSPIRATION ESTIMATION", "CARBON-DIOXIDE EXCHANGE", "T", "DECIDUOUS FOREST", "EDDY-COVARIANCE", "Environmental sciences", "TEMPERATE FOREST", "13. Climate action", "Earth and Environmental Sciences", "[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]", "INTERANNUAL VARIABILITY", "[PHYS.ASTR] Physics [physics]/Astrophysics [astro-ph]"]}, "links": [{"href": "https://hess.copernicus.org/articles/22/4513/2018/hess-22-4513-2018.pdf"}, {"href": "https://doi.org/10.5194/hess-22-4513-2018"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Hydrology%20and%20Earth%20System%20Sciences", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.5194/hess-22-4513-2018", "name": "item", "description": "10.5194/hess-22-4513-2018", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.5194/hess-22-4513-2018"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2018-08-27T00:00:00Z"}}, {"id": "10.5194/gmd-10-1903-2017", "type": "Feature", "geometry": null, "properties": {"license": "Open Access", "updated": "2026-04-13T16:22:54Z", "type": "Journal Article", "created": "2017-05-17", "title": "GLEAM\u00a0v3: satellite-based land evaporation and root-zone soil moisture", "description": "Abstract. The Global Land Evaporation Amsterdam Model (GLEAM) is a set of algorithms dedicated to the estimation of terrestrial evaporation and root-zone soil moisture from satellite data. Ever since its development in 2011, the model has been regularly revised, aiming at the optimal incorporation of new satellite-observed geophysical variables, and improving the representation of physical processes. In this study, the next version of this model (v3) is presented. Key changes relative to the previous version include (1)\uffc2\uffa0a revised formulation of the evaporative stress, (2)\uffc2\uffa0an optimized drainage algorithm, and (3)\uffc2\uffa0a new soil moisture data assimilation system. GLEAM\uffc2\uffa0v3 is used to produce three new data sets of terrestrial evaporation and root-zone soil moisture, including a 36-year data set spanning 1980\uffe2\uff80\uff932015, referred to as v3a (based on satellite-observed soil moisture, vegetation optical depth and snow-water equivalent, reanalysis air temperature and radiation, and a multi-source precipitation product), and two satellite-based data sets. The latter share most of their forcing, except for the vegetation optical depth and soil moisture, which are based on observations from different passive and active C- and L-band microwave sensors (European Space Agency Climate Change Initiative, ESA CCI) for the v3b data set (spanning 2003\uffe2\uff80\uff932015) and observations from the Soil Moisture and Ocean Salinity (SMOS) satellite in the v3c data set (spanning 2011\uffe2\uff80\uff932015). Here, these three data sets are described in detail, compared against analogous data sets generated using the previous version of GLEAM (v2), and validated against measurements from 91 eddy-covariance towers and 2325 soil moisture sensors across a broad range of ecosystems. Results indicate that the quality of the v3 soil moisture is consistently better than the one from v2: average correlations against in situ surface soil moisture measurements increase from 0.61 to 0.64 in the case of the v3a data set and the representation of soil moisture in the second layer improves as well, with correlations increasing from 0.47 to 0.53. Similar improvements are observed for the v3b and c data sets. Despite regional differences, the quality of the evaporation fluxes remains overall similar to the one obtained using the previous version of GLEAM, with average correlations against eddy-covariance measurements ranging between 0.78 and 0.81 for the different data sets. These global data sets of terrestrial evaporation and root-zone soil moisture are now openly available at www.GLEAM.eu and may be used for large-scale hydrological applications, climate studies, or research on land\uffe2\uff80\uff93atmosphere feedbacks.
", "keywords": ["TERRESTRIAL WATER FLUXES", "QE1-996.5", "PONDEROSA PINE", "CARBON-DIOXIDE EXCHANGE", "WACMOS-ET PROJECT", "TRIPLE COLLOCATION ANALYSIS", "DATA ASSIMILATION SYSTEM", "Geology", "15. Life on land", "01 natural sciences", "DECIDUOUS FOREST", "EDDY-COVARIANCE", "PARAMETER RETRIEVAL MODEL", "13. Climate action", "Earth and Environmental Sciences", "ENERGY-BALANCE", "14. Life underwater", "0105 earth and related environmental sciences"]}, "links": [{"href": "https://gmd.copernicus.org/articles/10/1903/2017/gmd-10-1903-2017.pdf"}, {"href": "https://doi.org/10.5194/gmd-10-1903-2017"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Geoscientific%20Model%20Development", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.5194/gmd-10-1903-2017", "name": "item", "description": "10.5194/gmd-10-1903-2017", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.5194/gmd-10-1903-2017"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2016-08-05T00:00:00Z"}}, {"id": "2164/13497", "type": "Feature", "geometry": null, "properties": {"updated": "2026-04-13T16:27:02Z", "type": "Journal Article", "created": "2019-08-30", "title": "How to measure, report and verify soil carbon change to realize the potential of soil carbon sequestration for atmospheric greenhouse gas removal", "description": "AbstractThere is growing international interest in better managing soils to increase soil organic carbon (SOC) content to contribute to climate change mitigation, to enhance resilience to climate change and to underpin food security, through initiatives such as international \uffe2\uff80\uff984p1000\uffe2\uff80\uff99 initiative and the FAO's Global assessment of SOC sequestration potential (GSOCseq) programme. Since SOC content of soils cannot be easily measured, a key barrier to implementing programmes to increase SOC at large scale, is the need for credible and reliable measurement/monitoring, reporting and verification (MRV) platforms, both for national reporting and for emissions trading. Without such platforms, investments could be considered risky. In this paper, we review methods and challenges of measuring SOC change directly in soils, before examining some recent novel developments that show promise for quantifying SOC. We describe how repeat soil surveys are used to estimate changes in SOC over time, and how long\uffe2\uff80\uff90term experiments and space\uffe2\uff80\uff90for\uffe2\uff80\uff90time substitution sites can serve as sources of knowledge and can be used to test models, and as potential benchmark sites in global frameworks to estimate SOC change. We briefly consider models that can be used to simulate and project change in SOC and examine the MRV platforms for SOC change already in use in various countries/regions. In the final section, we bring together the various components described in this review, to describe a new vision for a global framework for MRV of SOC change, to support national and international initiatives seeking to effect change in the way we manage our soils.