{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,31]],"date-time":"2025-10-31T07:51:11Z","timestamp":1761897071485,"version":"build-2065373602"},"reference-count":89,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2019,7,10]],"date-time":"2019-07-10T00:00:00Z","timestamp":1562716800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["41701393"],"award-info":[{"award-number":["41701393"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100002858","name":"China Postdoctoral Science Foundation","doi-asserted-by":"publisher","award":["2017M621698"],"award-info":[{"award-number":["2017M621698"]}],"id":[{"id":"10.13039\/501100002858","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Zhejiang Provincial Natural Science Foundation of China","award":["LY18D010003"],"award-info":[{"award-number":["LY18D010003"]}]},{"name":"Foundation of Key Laboratory of Agricultural Remote Sensing, Ministry of Agriculture","award":["201709"],"award-info":[{"award-number":["201709"]}]},{"name":"Foundation of Jiangsu Key Laboratory of Agricultural Meteorology, Nanjing University of Information Science and Technology","award":["JKLAM1702"],"award-info":[{"award-number":["JKLAM1702"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Proper determinations of light use efficiency (LUE) and absorbed photosynthetically active radiation (APAR) are essential for LUE models to simulate gross primary productivity (GPP). This study intended to apply the photochemical reflectance index (PRI) to track LUE or APAR variations in a subtropical coniferous forest using tower-based PRI and GPP measurements. To improve the ability of using PRI to track LUE or APAR, a two-leaf approach differentiating sunlit and shaded leaves was used to process the remote sensing and flux data. However, penumbra region, the \u2018grey region\u2019 between sunlit and shaded leaves, increases the difficulty for quantifying the fractions of sunlit and shaded leaves. Firstly, three methods with different ways on treating the penumbra region were investigated for estimating the fraction of sunlit leaves (PT). After evaluating the correlations between observed PRI (PRIobs) and inversely retrieved PRI (PRIinv) from estimated PT using the three methods, we found that treating a substantial portion of penumbra region as sunlit leaves was reasonable and using the ratio of canopy reflectance to leaf reflectance as PT was accurate and efficient. Based on this, we used the two-leaf approach to estimate the canopy-level PRI, aiming to evaluate the ability of using PRI as a proxy for LUE or APAR. Results showed that PRI was able to capture half-hourly and daily changes in LUE and APAR, and the two-leaf approach could enhance the correlations between PRI and both LUE and APAR at both half-hourly and daily time steps. Strong diurnal correlations (averaged R = 0.82 from 173 days) between two-leaf PRI and APAR were found on more than 80% days and the relationship between them over the whole study period was also very significant (R2 &gt; 0.5, p &lt;0.0001) regardless of different climate conditions, suggesting that the two-leaf PRI was probably a better proxy for APAR than for LUE at short-term scale as PRI mainly represented the absorbed energy allocated to photoprotection at short time scale and was a direct outcome driven by APAR. However, the scattered relationships of PRI with LUE and APAR indicated there were still many limitations in usage of PRI to accurately estimate physiological parameters affected by changing weather conditions, pigment pool size, etc., which needed further exploration.<\/jats:p>","DOI":"10.3390\/rs11141643","type":"journal-article","created":{"date-parts":[[2019,7,10]],"date-time":"2019-07-10T11:56:51Z","timestamp":1562759811000},"page":"1643","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Evaluation of Different Methods for Estimating the Fraction of Sunlit Leaves and Its Contribution for Photochemical Reflectance Index Utilization in a Coniferous Forest"],"prefix":"10.3390","volume":"11","author":[{"given":"Qing","family":"Huang","sequence":"first","affiliation":[{"name":"Key Laboratory of Agricultural Remote Sensing, Mnistry of Agriculture and Rural Affairs, Beijing 100081, China"},{"name":"Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, International Institute for Earth System Science, Nanjing University, Nanjing 210023, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0422-3493","authenticated-orcid":false,"given":"Feng","family":"Qiu","sequence":"additional","affiliation":[{"name":"Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, International Institute for Earth System Science, Nanjing University, Nanjing 210023, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Weiliang","family":"Fan","sequence":"additional","affiliation":[{"name":"School of Environmental and Resources Science, Zhejiang A &amp; F University, Lin\u2019an 311300, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4345-0138","authenticated-orcid":false,"given":"Yibo","family":"Liu","sequence":"additional","affiliation":[{"name":"Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Jiangsu Key Laboratory of Agricultural Meteorology, School of Applied Meteorology, Nanjing University of Information Science &amp; Technology, Nanjing 210044, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0860-4023","authenticated-orcid":false,"given":"Qian","family":"Zhang","sequence":"additional","affiliation":[{"name":"Key Laboratory of Agricultural Remote Sensing, Mnistry of Agriculture and Rural Affairs, Beijing 100081, China"},{"name":"Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, International Institute for Earth System Science, Nanjing University, Nanjing 210023, China"},{"name":"Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Jiangsu Key Laboratory of Agricultural Meteorology, School of Applied Meteorology, Nanjing University of Information Science &amp; Technology, Nanjing 210044, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,7,10]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"747","DOI":"10.2307\/2401901","article-title":"Solar radiation and productivity in tropical ecosystems","volume":"9","author":"Monteith","year":"1972","journal-title":"J. Appl. Ecol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2777","DOI":"10.1016\/j.rse.2008.01.011","article-title":"Separating physiologically and directionally induced changes in pri using brdf models","volume":"112","author":"Hilker","year":"2008","journal-title":"Remote Sens. Environ."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"655","DOI":"10.1177\/0309133312452187","article-title":"A review of remote sensing based productivity models and their suitability for studying oil palm productivity in tropical regions","volume":"36","author":"Tan","year":"2012","journal-title":"Prog. Phys. Geogr."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"411","DOI":"10.1016\/j.scitotenv.2007.11.007","article-title":"The use of remote sensing in light use efficiency based models of gross primary production: A review of current status and future requirements","volume":"404","author":"Hilker","year":"2008","journal-title":"Sci. Total Environ."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"168","DOI":"10.1016\/j.rse.2004.07.003","article-title":"Heterogeneity of light use efficiency in a northern wisconsin forest: Implications for modeling net primary production with remote sensing","volume":"93","author":"Ahl","year":"2004","journal-title":"Remote Sens. Environ."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"811","DOI":"10.1029\/93GB02725","article-title":"Terrestrial ecosystem production: A process model based on global satellite and surface data","volume":"7","author":"Potter","year":"1993","journal-title":"Glob. Biogeochem. Cycles"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Running, S.W., Thornton, P.E., Nemani, R., and Glassy, J.M. (2000). Global terrestrial gross and net primary productivity from the earth observing system. Methods in Ecosystem Science, Springer.","DOI":"10.1007\/978-1-4612-1224-9_4"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"547","DOI":"10.1641\/0006-3568(2004)054[0547:ACSMOG]2.0.CO;2","article-title":"A continuous satellite-derived measure of global terrestrial primary production","volume":"54","author":"Running","year":"2004","journal-title":"BioScience"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"256","DOI":"10.1016\/j.rse.2004.03.010","article-title":"Modeling gross primary production of temperate deciduous broadleaf forest using satellite images and climate data","volume":"91","author":"Xiao","year":"2004","journal-title":"Remote Sens. Environ."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"519","DOI":"10.1016\/j.rse.2003.11.008","article-title":"Satellite-based modeling of gross primary production in an evergreen needleleaf forest","volume":"89","author":"Xiao","year":"2004","journal-title":"Remote Sens. Environ."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"481","DOI":"10.1109\/TGRS.1995.8746029","article-title":"The interpretation of spectral vegetation indexes","volume":"33","author":"Myneni","year":"1995","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"5263","DOI":"10.1029\/93JD03221","article-title":"Methodology for the estimation of terrestrial net primary production from remotely sensed data","volume":"99","author":"Ruimy","year":"1994","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1016\/S0065-2504(08)60029-X","article-title":"Modelling terrestrial carbon exchange and storage: Evidence and implications of functional convergence in light-use efficiency","volume":"28","author":"Goetz","year":"1999","journal-title":"Adv. Ecol. Res."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"412","DOI":"10.1111\/j.1365-3040.2004.01280.x","article-title":"Net primary production and light use efficiency in a mixed coniferous forest in sweden","volume":"28","author":"Lagergren","year":"2005","journal-title":"Plant Cell Environ."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"28","DOI":"10.1016\/j.agrformet.2013.01.003","article-title":"Development of a two-leaf light use efficiency model for improving the calculation of terrestrial gross primary productivity","volume":"173","author":"He","year":"2013","journal-title":"Agric. For. Meteorol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"781","DOI":"10.1016\/j.agrformet.2011.01.005","article-title":"The role of sky conditions on gross primary production in a mixed deciduous forest","volume":"151","author":"Oliphant","year":"2011","journal-title":"Agric. For. Meteorol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"803","DOI":"10.1016\/j.agrformet.2011.01.011","article-title":"Effects of cloudiness change on net ecosystem exchange, light use efficiency, and water use efficiency in typical ecosystems of china","volume":"151","author":"Zhang","year":"2011","journal-title":"Agric. For. Meteorol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1442","DOI":"10.2134\/agronj2005.0322","article-title":"Temperature influence on potato leaf and branch distribution and on canopy photosynthetic rate","volume":"98","author":"Fleisher","year":"2006","journal-title":"Agron. J."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1016\/S0168-1923(99)00167-7","article-title":"Remote sensing of photosynthetic-light-use efficiency of boreal forest","volume":"101","author":"Nichol","year":"2000","journal-title":"Agric. For. Meteorol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"677","DOI":"10.3402\/tellusb.v54i5.16710","article-title":"Remote sensing of photosynthetic light use efficiency of a siberian boreal forest","volume":"54","author":"Nichol","year":"2002","journal-title":"Tellus B"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1416","DOI":"10.1016\/j.rse.2010.01.022","article-title":"Global estimates of evapotranspiration and gross primary production based on modis and global meteorology data","volume":"114","author":"Yuan","year":"2010","journal-title":"Remote Sens. Environ."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"788","DOI":"10.1525\/bio.2010.60.10.5","article-title":"Estimation of light-use efficiency of terrestrial ecosystems from space: A status report","volume":"60","author":"Coops","year":"2010","journal-title":"BioScience"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1016\/S0304-3800(99)00156-8","article-title":"Daily canopy photosynthesis model through temporal and spatial scaling for remote sensing applications","volume":"124","author":"Chen","year":"1999","journal-title":"Ecol. Model."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"626","DOI":"10.1029\/2010GB003996","article-title":"Effects of foliage clumping on the estimation of global terrestrial gross primary productivity","volume":"26","author":"Chen","year":"2012","journal-title":"Glob. Biogeochem. Cycles"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"175","DOI":"10.1016\/j.solener.2015.07.033","article-title":"Impact of estimated solar radiation on gross primary productivity simulation in subtropical plantation in southeast china","volume":"120","author":"Li","year":"2015","journal-title":"Sol. Energy"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1014","DOI":"10.1038\/nature07949","article-title":"Impact of changes in diffuse radiation on the global land carbon sink","volume":"458","author":"Mercado","year":"2009","journal-title":"Nature"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1007\/s004420100760","article-title":"On the direct effect of clouds and atmospheric particles on the productivity and structure of vegetation","volume":"129","author":"Roderick","year":"2001","journal-title":"Oecologia"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"2238","DOI":"10.3390\/rs70302238","article-title":"Performance of linear and nonlinear two-leaf light use efficiency models at different temporal scales","volume":"7","author":"Wu","year":"2015","journal-title":"Remote Sens."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1016\/0034-4257(92)90059-S","article-title":"A narrow-waveband spectral index that tracks diurnal changes in photosynthetic efficiency","volume":"41","author":"Gamon","year":"1992","journal-title":"Remote Sens. Environ."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"377","DOI":"10.1007\/BF00403596","article-title":"Photochemical efficiency of photosystem ii, photon yield of o2 evolution, photosynthetic capacity, and carotenoid composition during the midday depression of net co2 uptake in arbutus unedo growing in portugal","volume":"177","author":"Adams","year":"1989","journal-title":"Planta"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"474","DOI":"10.1093\/oxfordjournals.pcp.a029394","article-title":"Survey of thermal energy dissipation and pigment composition in sun and shade leaves","volume":"39","year":"1998","journal-title":"Plant Cell Physiol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"599","DOI":"10.1146\/annurev.pp.43.060192.003123","article-title":"Photoprotection and other responses of plants to high light stress","volume":"43","author":"Adams","year":"1992","journal-title":"Annu. Rev. Plant Biol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1016\/S1360-1385(96)80019-7","article-title":"The role of xanthophyll cycle carotenoids in the protection of photosynthesis","volume":"1","author":"Adams","year":"1996","journal-title":"Trends Plant Sci."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1111\/j.1469-8137.2006.01835.x","article-title":"Photoprotection in an ecological context: The remarkable complexity of thermal energy dissipation","volume":"172","author":"Adams","year":"2006","journal-title":"New Phytol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"492","DOI":"10.1007\/s004420050337","article-title":"The photochemical reflectance index: An optical indicator of photosynthetic radiation use efficiency across species, functional types, and nutrient levels","volume":"112","author":"Gamon","year":"1997","journal-title":"Oecologia"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"291","DOI":"10.1111\/j.1469-8137.1995.tb03064.x","article-title":"Assessment of photosynthetic radiation-use efficiency with spectral reflectance","volume":"131","author":"Filella","year":"1995","journal-title":"New Phytol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"264","DOI":"10.1016\/S0034-4257(01)00224-3","article-title":"Remote sensing of canopy light use efficiency using the photochemical reflectance index model and sensitivity analysis","volume":"78","author":"Barton","year":"2001","journal-title":"Remote Sens. Environ."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"202","DOI":"10.1016\/j.rse.2014.09.031","article-title":"Impact of varying irradiance on vegetation indices and chlorophyll fluorescence derived from spectroscopy data","volume":"156","author":"Damm","year":"2015","journal-title":"Remote Sens. Environ."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"212","DOI":"10.1016\/j.rse.2005.07.006","article-title":"A modis-derived photochemical reflectance index to detect inter-annual variations in the photosynthetic light-use efficiency of a boreal deciduous forest","volume":"98","author":"Drolet","year":"2005","journal-title":"Remote Sens. Environ."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"3064","DOI":"10.1016\/j.rse.2008.03.002","article-title":"Regional mapping of gross light-use efficiency using modis spectral indices","volume":"112","author":"Drolet","year":"2008","journal-title":"Remote Sens. Environ."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"141","DOI":"10.1016\/j.rse.2013.03.032","article-title":"Effects of irradiance and photosynthetic downregulation on the photochemical reflectance index in douglas-fir and ponderosa pine","volume":"135","author":"Gamon","year":"2013","journal-title":"Remote Sens. Environ."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1016\/j.rse.2010.08.023","article-title":"The photochemical reflectance index (pri) and the remote sensing of leaf, canopy and ecosystem radiation use efficienciesa review and meta-analysis","volume":"115","author":"Garbulsky","year":"2011","journal-title":"Remote Sens. Environ."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"2360","DOI":"10.1016\/j.rse.2011.04.036","article-title":"Assessing structural effects on pri for stress detection in conifer forests","volume":"115","author":"Morales","year":"2011","journal-title":"Remote Sens. Environ."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"73","DOI":"10.1016\/j.rse.2014.01.017","article-title":"Relationships between photochemical reflectance index and light-use efficiency in deciduous and evergreen broadleaf forests","volume":"144","author":"Soudani","year":"2014","journal-title":"Remote Sens. Environ."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"444","DOI":"10.1016\/j.rse.2012.05.030","article-title":"The photochemical reflectance index from directional cornfield reflectances: Observations and simulations","volume":"124","author":"Cheng","year":"2012","journal-title":"Remote Sens. Environ."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"54","DOI":"10.1016\/j.isprsjprs.2015.03.012","article-title":"Diffuse sky radiation influences the relationship between canopy pri and shadow fraction","volume":"105","author":"Takala","year":"2015","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"138","DOI":"10.1016\/j.isprsjprs.2014.08.012","article-title":"Tracking seasonal changes of leaf and canopy light use efficiency in a phlomis fruticosa mediterranean ecosystem using field measurements and multi-angular satellite hyperspectral imagery","volume":"97","author":"Stagakis","year":"2014","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"1859","DOI":"10.1109\/TGRS.2016.2615102","article-title":"Modeling gross primary production for sunlit and shaded canopies across an evergreen and a deciduous site in canada","volume":"55","author":"Zhou","year":"2017","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/s00442-007-0957-y","article-title":"Photochemistry, remotely sensed physiological reflectance index and de-epoxidation state of the xanthophyll cycle in quercus coccifera under intense drought","volume":"156","author":"Morales","year":"2008","journal-title":"Oecologia"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"313","DOI":"10.1007\/s00442-012-2317-9","article-title":"Physiology of the seasonal relationship between the photochemical reflectance index and photosynthetic light use efficiency","volume":"170","author":"Nichol","year":"2012","journal-title":"Oecologia"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"289","DOI":"10.1016\/j.rse.2005.01.020","article-title":"Parallel adjustments in vegetation greenness and ecosystem CO2 exchange in response to drought in a southern california chaparral ecosystem","volume":"103","author":"Sims","year":"2006","journal-title":"Remote Sens. Environ."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"415","DOI":"10.1146\/annurev.pp.35.060184.002215","article-title":"Photorespiration: Pathways, regulation, and modification","volume":"35","author":"Ogren","year":"1984","journal-title":"Annu. Rev. Plant Physiol."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"1517","DOI":"10.1098\/rstb.2000.0712","article-title":"Photorespiration: Metabolic pathways and their role in stress protection","volume":"355","author":"Wingler","year":"2000","journal-title":"Philos. Trans. R. Soc. B Biol. Sci."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"85","DOI":"10.1016\/0034-4257(92)90070-Z","article-title":"Spatial heterogeneity in vegetation canopies and remote sensing of absorbed photosynthetically active radiation: A modeling study","volume":"41","author":"Asrar","year":"1992","journal-title":"Remote Sens. Environ."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"1380","DOI":"10.1109\/36.649788","article-title":"Estimation of global leaf area index and absorbed par using radiative transfer models","volume":"35","author":"Myneni","year":"2002","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.rse.2014.07.012","article-title":"Estimation of crop gross primary production (gpp): Fapar chl versus mod15a2 fpar","volume":"153","author":"Zhang","year":"2014","journal-title":"Remote Sens. Environ."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1016\/j.agrformet.2014.02.002","article-title":"Estimation of crop gross primary production (gpp): I. Impact of modis observation footprint and impact of vegetation brdf characteristics","volume":"191","author":"Zhang","year":"2014","journal-title":"Agric. For. Meteorol."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.agrformet.2014.09.003","article-title":"Estimation of crop gross primary production (gpp): Ii. Do scaled modis vegetation indices improve performance?","volume":"200","author":"Zhang","year":"2015","journal-title":"Agric. For. Meteorol."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.chnaes.2015.12.003","article-title":"Sensitivity analysis of retrieving fraction of absorbed photosynthetically active radiation (fpar) using remote sensing data","volume":"36","author":"Dong","year":"2016","journal-title":"Acta Ecol. Sin."},{"key":"ref_60","doi-asserted-by":"crossref","unstructured":"Liang, S., Zheng, T., Liu, R., Fang, H., Tsay, S.C., and Running, S. (2006). Estimation of incident photosynthetically active radiation from moderate resolution imaging spectrometer data. J. Geophys. Res. Atmos., 111.","DOI":"10.1029\/2005JD006730"},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"998","DOI":"10.1016\/j.rse.2007.07.021","article-title":"Mapping incident photosynthetically active radiation from modis data over china","volume":"112","author":"Liu","year":"2008","journal-title":"Remote Sens. Environ."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"4065","DOI":"10.1093\/jxb\/eru191","article-title":"Linking chlorophyll a fluorescence to photosynthesis for remote sensing applications: Mechanisms and challenges","volume":"65","author":"Atherton","year":"2014","journal-title":"J. Exp. Bot."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"175","DOI":"10.1016\/j.rse.2004.03.012","article-title":"A new instrument for passive remote sensing: 2. Measurement of leaf and canopy reflectance changes at 531 nm and their relationship with photosynthesis and chlorophyll fluorescence","volume":"91","author":"Evain","year":"2004","journal-title":"Remote Sens. Environ."},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"1918","DOI":"10.1016\/j.rse.2011.03.014","article-title":"Photosynsat, photosynthesis from space: Theoretical foundations of a satellite concept and validation from tower and spaceborne data","volume":"115","author":"Hall","year":"2011","journal-title":"Remote Sens. Environ."},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"3201","DOI":"10.1016\/j.rse.2008.03.015","article-title":"Multi-angle remote sensing of forest light use efficiency by observing pri variation with canopy shadow fraction","volume":"112","author":"Hall","year":"2008","journal-title":"Remote Sens. Environ."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"819","DOI":"10.1007\/s00468-010-0452-7","article-title":"Comparing canopy metrics derived from terrestrial and airborne laser scanning in a douglas-fir dominated forest stand","volume":"24","author":"Hilker","year":"2010","journal-title":"Trees"},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"ACL 2-1","DOI":"10.1029\/2001JD001242","article-title":"Advantages of diffuse radiation for terrestrial ecosystem productivity","volume":"107","author":"Gu","year":"2002","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"169","DOI":"10.1007\/BF00317729","article-title":"Canopy structure and vertical patterns of photosynthesis and related leaf traits in a deciduous forest","volume":"96","author":"Ellsworth","year":"1993","journal-title":"Oecologia"},{"key":"ref_69","doi-asserted-by":"crossref","first-page":"159","DOI":"10.2307\/2401415","article-title":"Stand structure and light penetration. Iii. Sunlit foliage area","volume":"4","author":"Wilson","year":"1967","journal-title":"J. Appl. Ecol."},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"1316","DOI":"10.1109\/36.628798","article-title":"A four-scale bidirectional reflectance model based on canopy architecture","volume":"35","author":"Chen","year":"1997","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"5469","DOI":"10.1109\/TGRS.2013.2289852","article-title":"Gost: A geometric-optical model for sloping terrains","volume":"52","author":"Fan","year":"2014","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_72","doi-asserted-by":"crossref","first-page":"1423","DOI":"10.1109\/JSTARS.2015.2413994","article-title":"Gost2: The improvement of the canopy reflectance model gost in separating the sunlit and shaded leaves","volume":"8","author":"Fan","year":"2015","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_73","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.rse.2017.03.012","article-title":"Improving the ability of the photochemical reflectance index to track canopy light use efficiency through differentiating sunlit and shaded leaves","volume":"194","author":"Zhang","year":"2017","journal-title":"Remote Sens. Environ."},{"key":"ref_74","doi-asserted-by":"crossref","first-page":"215","DOI":"10.1016\/0304-3800(93)E0086-I","article-title":"Penumbra in within-shoot and between-shoot shading in conifers and its significance for photosynthesis","volume":"77","author":"Stenberg","year":"1995","journal-title":"Ecol. Model."},{"key":"ref_75","doi-asserted-by":"crossref","first-page":"166","DOI":"10.1016\/j.agrformet.2006.02.005","article-title":"Soil moisture effect on the temperature dependence of ecosystem respiration in a subtropical pinus plantation of southeastern china","volume":"137","author":"Wen","year":"2006","journal-title":"Agric. For. Meteorol."},{"key":"ref_76","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1016\/S0168-1923(00)00225-2","article-title":"Gap filling strategies for defensible annual sums of net ecosystem exchange \u2606","volume":"107","author":"Falge","year":"2001","journal-title":"Agric. For. Meteorol."},{"key":"ref_77","doi-asserted-by":"crossref","unstructured":"Lloyd, J., and Taylor, J. (1994). On the temperature dependence of soil respiration. Funct. Ecol., 315\u2013323.","DOI":"10.2307\/2389824"},{"key":"ref_78","doi-asserted-by":"crossref","first-page":"16938","DOI":"10.3390\/rs71215860","article-title":"Ability of the photochemical reflectance index to track light use efficiency for a sub-tropical planted coniferous forest","volume":"7","author":"Zhang","year":"2015","journal-title":"Remote Sens."},{"key":"ref_79","doi-asserted-by":"crossref","first-page":"5579","DOI":"10.1109\/TGRS.2013.2290590","article-title":"Hybrid geometric optical\u2013radiative transfer model suitable for forests on slopes","volume":"52","author":"Fan","year":"2014","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_80","doi-asserted-by":"crossref","first-page":"2863","DOI":"10.1016\/j.rse.2010.07.004","article-title":"Remote sensing of photosynthetic light-use efficiency across two forested biomes: Spatial scaling","volume":"114","author":"Hilker","year":"2010","journal-title":"Remote Sens. Environ."},{"key":"ref_81","doi-asserted-by":"crossref","first-page":"166","DOI":"10.5589\/m09-008","article-title":"Linking foliage spectral responses to canopy-level ecosystem photosynthetic light-use efficiency at a douglas-fir forest in canada","volume":"35","author":"Middleton","year":"2009","journal-title":"Can. J. Remote Sens."},{"key":"ref_82","doi-asserted-by":"crossref","first-page":"865","DOI":"10.1007\/s00442-010-1901-0","article-title":"Tracking plant physiological properties from multi-angular tower-based remote sensing","volume":"165","author":"Hilker","year":"2011","journal-title":"Oecologia"},{"key":"ref_83","doi-asserted-by":"crossref","first-page":"825","DOI":"10.1093\/treephys\/28.6.825","article-title":"Effects of mutual shading of tree crowns on prediction of photosynthetic light-use efficiency in a coastal douglas fir forest","volume":"28","author":"Hilker","year":"2008","journal-title":"Tree Physiol."},{"key":"ref_84","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1111\/nph.13159","article-title":"Three causes of variation in the photochemical reflectance index (pri) in evergreen conifers","volume":"206","author":"Wong","year":"2015","journal-title":"New Phytol."},{"key":"ref_85","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/BF00317336","article-title":"Remote sensing of the xanthophyll cycle and chlorophyll fluorescence in sunflower leaves and canopies","volume":"85","author":"Gamon","year":"1990","journal-title":"Oecologia"},{"key":"ref_86","doi-asserted-by":"crossref","first-page":"345","DOI":"10.1146\/annurev.pp.29.060178.002021","article-title":"Energy distribution in the photochemical apparatus of photosynthesis","volume":"29","author":"Butler","year":"1978","journal-title":"Annu. Rev. Plant Physiol."},{"key":"ref_87","doi-asserted-by":"crossref","first-page":"344","DOI":"10.1111\/nph.12453","article-title":"Assessing leaf photoprotective mechanisms using terrestrial lidar: Towards mapping canopy photosynthetic performance in three dimensions","volume":"201","author":"Magney","year":"2014","journal-title":"New Phytol."},{"key":"ref_88","doi-asserted-by":"crossref","first-page":"84","DOI":"10.1016\/j.rse.2015.11.013","article-title":"Response of high frequency photochemical reflectance index (pri) measurements to environmental conditions in wheat","volume":"173","author":"Magney","year":"2016","journal-title":"Remote Sens. Environ."},{"key":"ref_89","doi-asserted-by":"crossref","first-page":"322","DOI":"10.1016\/j.rse.2017.03.025","article-title":"Linking stand architecture with canopy reflectance to estimate vertical patterns of light-use efficiency","volume":"194","author":"Coops","year":"2017","journal-title":"Remote Sens. Environ."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/11\/14\/1643\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T13:04:23Z","timestamp":1760187863000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/11\/14\/1643"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,7,10]]},"references-count":89,"journal-issue":{"issue":"14","published-online":{"date-parts":[[2019,7]]}},"alternative-id":["rs11141643"],"URL":"https:\/\/doi.org\/10.3390\/rs11141643","relation":{},"ISSN":["2072-4292"],"issn-type":[{"type":"electronic","value":"2072-4292"}],"subject":[],"published":{"date-parts":[[2019,7,10]]}}}