{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,9]],"date-time":"2026-07-09T04:20:52Z","timestamp":1783570852237,"version":"3.55.0"},"reference-count":71,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2018,2,8]],"date-time":"2018-02-08T00:00:00Z","timestamp":1518048000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Significant gaps exist in our knowledge of the impact of leaf aging on canopy signal variability, which limits our understanding of vegetation status based on remotely sensed data. To understand the effects of leaf aging at the leaf and canopy scales, a combination of field, remote-sensing and physical modeling techniques was adopted to assess the canopy spectral signals of evergreen Cunninghamia forests. We observed an approximately 10% increase in Near-Infrared (NIR) reflectance for new leaves and a 35% increase in NIR transmittance for mature leaves from May to October. When variations in leaf optical properties (LOPs) of only mature leaves, or both new and mature leaves were considered, the Geometric Optical and Radiative Transfer (GORT) model-simulated canopy reflectance trajectory was more consistent with Landsat observations (R2 increased from 0.37 to 0.82~0.89 for NIR reflectance, and from 0.35 to 0.67~0.88 for EVI2, with a small RMSE (0.01 to 0.02)). This study highlights the importance of leaf age on leaf spectral signatures, and provides evidence of age-dependent LOPs that have important impacts on canopy reflectance in the NIR band and EVI2, which are used to monitor canopy dynamics and productivity, with important implications for RS and forest ecosystem ecology.<\/jats:p>","DOI":"10.3390\/rs10020262","type":"journal-article","created":{"date-parts":[[2018,2,9]],"date-time":"2018-02-09T12:46:27Z","timestamp":1518180387000},"page":"262","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":21,"title":["Impacts of Leaf Age on Canopy Spectral Signature Variation in Evergreen Chinese Fir Forests"],"prefix":"10.3390","volume":"10","author":[{"given":"Qiaoli","family":"Wu","sequence":"first","affiliation":[{"name":"State Key Laboratory of Remote Sensing Science, Jointly Sponsored by Beijing Normal University and Institute of Remote Sensing and Digital Earth of Chinese Academy of Sciences, Beijing 100875, China"},{"name":"Beijing Engineering Research Center for Global Land Remote sensing Products, Institute of Remote Sensing Science and Engineering, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4099-4906","authenticated-orcid":false,"given":"Conghe","family":"Song","sequence":"additional","affiliation":[{"name":"Department of Geography, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jinling","family":"Song","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Remote Sensing Science, Jointly Sponsored by Beijing Normal University and Institute of Remote Sensing and Digital Earth of Chinese Academy of Sciences, Beijing 100875, China"},{"name":"Beijing Engineering Research Center for Global Land Remote sensing Products, Institute of Remote Sensing Science and Engineering, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4962-4888","authenticated-orcid":false,"given":"Jindi","family":"Wang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Remote Sensing Science, Jointly Sponsored by Beijing Normal University and Institute of Remote Sensing and Digital Earth of Chinese Academy of Sciences, Beijing 100875, China"},{"name":"Beijing Engineering Research Center for Global Land Remote sensing Products, Institute of Remote Sensing Science and Engineering, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shaoyuan","family":"Chen","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Remote Sensing Science, Jointly Sponsored by Beijing Normal University and Institute of Remote Sensing and Digital Earth of Chinese Academy of Sciences, Beijing 100875, China"},{"name":"Beijing Engineering Research Center for Global Land Remote sensing Products, Institute of Remote Sensing Science and Engineering, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bo","family":"Yu","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Remote Sensing Science, Jointly Sponsored by Beijing Normal University and Institute of Remote Sensing and Digital Earth of Chinese Academy of Sciences, Beijing 100875, China"},{"name":"Beijing Engineering Research Center for Global Land Remote sensing Products, Institute of Remote Sensing Science and Engineering, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2018,2,8]]},"reference":[{"key":"ref_1","unstructured":"Waring, R.H., and Schlesinger, W.H. (1985). Forest Ecosystems: Concepts and Management, Academic Press."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1126\/science.263.5144.185","article-title":"Carbon pools and flux of global forest ecosystems","volume":"263","author":"Dixon","year":"1994","journal-title":"Science (Washington)"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"436","DOI":"10.1073\/pnas.1407302112","article-title":"Effect of increasing CO2 on the terrestrial carbon cycle","volume":"112","author":"Schimel","year":"2015","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"988","DOI":"10.1126\/science.1201609","article-title":"A large and persistent carbon sink in the world\u2019s forests","volume":"333","author":"Pan","year":"2014","journal-title":"Science"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"346","DOI":"10.1038\/nclimate1233","article-title":"Biogeochemistry: Taking stock of forest carbon","volume":"1","author":"Reich","year":"2016","journal-title":"Nat. Clim. Chang."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1080\/10106048909354217","article-title":"Factors affecting the spectral response of forest canopies: A review","volume":"4","author":"Guyot","year":"1989","journal-title":"Geocarto Int."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"675","DOI":"10.1109\/36.581987","article-title":"Second simulation of the satellite signal in the solar spectrum, 6s: An overview","volume":"35","author":"Vermote","year":"1997","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1175\/2012EI440.1","article-title":"Why is remote sensing of Amazon forest greenness so challenging?","volume":"16","author":"Samanta","year":"2012","journal-title":"Earth Interact."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"385","DOI":"10.1016\/S0034-4257(02)00129-3","article-title":"Sensitivity of vegetation indices to atmospheric aerosols: Continental-scale observations in northern asia","volume":"84","author":"Xiao","year":"2003","journal-title":"Remote Sens. Environ."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2350","DOI":"10.1016\/j.rse.2011.04.035","article-title":"On intra-annual evi variability in the dry season of tropical forest: A case study with MODIS and hyperspectral data","volume":"115","author":"Roberts","year":"2011","journal-title":"Remote Sens. Environ."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"7176","DOI":"10.1002\/2014GL061535","article-title":"Can MODIS evi monitor ecosystem productivity in the Amazon rainforest?","volume":"41","author":"Maeda","year":"2014","journal-title":"Geophys. Res. Lett."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"332","DOI":"10.1080\/15481603.2015.1038428","article-title":"Sun-sensor geometry effects on vegetation index anomalies in the Amazon rainforest","volume":"52","author":"Maeda","year":"2015","journal-title":"GISci. Remote Sens."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"064014","DOI":"10.1088\/1748-9326\/10\/6\/064014","article-title":"Sunlight mediated seasonality in canopy structure and photosynthetic activity of Amazonian rainforests","volume":"10","author":"Bi","year":"2015","journal-title":"Environ. Res. Lett."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"260","DOI":"10.1016\/j.rse.2012.09.013","article-title":"Use of MISR\/Terra data to study intra- and inter-annual EVI variations in the dry season of tropical forest","volume":"127","author":"Moura","year":"2012","journal-title":"Remote Sens. Environ."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"385","DOI":"10.1016\/j.rse.2012.09.002","article-title":"Multi-angle implementation of atmospheric correction for MODIS (MAIAC): 3. Atmospheric correction","volume":"127","author":"Lyapustin","year":"2012","journal-title":"Remote Sens. Environ."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"124021","DOI":"10.1088\/1748-9326\/9\/12\/124021","article-title":"Asynchronous Amazon forest canopy phenology indicates adaptation to both water and light availability","volume":"9","author":"Jones","year":"2014","journal-title":"Environ. Res. Lett."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"119","DOI":"10.1016\/0034-4257(92)90131-3","article-title":"Vegetation canopy par absorptance and the normalized difference vegetation index: An assessment using the sail model","volume":"39","author":"Goward","year":"1992","journal-title":"Remote Sens. Environ."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"375","DOI":"10.1111\/j.1469-8137.2010.03536.x","article-title":"Sources of variability in canopy reflectance and the convergent properties of plants","volume":"189","author":"Ollinger","year":"2011","journal-title":"New Phytol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"234","DOI":"10.1016\/S0034-4257(98)00014-5","article-title":"Biophysical and biochemical sources of variability in canopy reflectance","volume":"64","author":"Asner","year":"1998","journal-title":"Remote Sens. Environ."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"S56","DOI":"10.1016\/j.rse.2008.01.026","article-title":"Prospect+ sail models: A review of use for vegetation characterization","volume":"113","author":"Jacquemoud","year":"2009","journal-title":"Remote Sens. Environ."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"408","DOI":"10.1016\/j.rse.2006.04.005","article-title":"Impact of understory vegetation on forest canopy reflectance and remotely sensed lai estimates","volume":"103","author":"Eriksson","year":"2006","journal-title":"Remote Sens. Environ."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"663","DOI":"10.2307\/1936256","article-title":"Derivation of leaf-area index from quality of light on the forest floor","volume":"50","author":"Jordan","year":"1969","journal-title":"Ecology"},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Samanta, A., Knyazikhin, Y., Xu, L., Dickinson, R.E., Fu, R., Costa, M.H., Saatchi, S.S., Nemani, R.R., and Myneni, R.B. (2012). Seasonal changes in leaf area of Amazon forests from leaf flushing and abscission. J. Geophys. Res. Biogeosci., 117.","DOI":"10.1029\/2011JG001818"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"569","DOI":"10.1111\/j.1469-8137.2010.03310.x","article-title":"Drought impacts on the Amazon forest: The remote sensing perspective","volume":"187","author":"Asner","year":"2010","journal-title":"New Phytol."},{"key":"ref_25","unstructured":"Monteith, J.L., and Ross, J. (1981). The Radiation Regime and Architecture of Plant Stands, Springer."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"243","DOI":"10.1016\/S0034-4257(97)00138-7","article-title":"Variability in leaf and litter optical properties: Implications for BRDF model inversions using AVHRR, MODIS, and MISR","volume":"63","author":"Asner","year":"1998","journal-title":"Remote Sens. Environ."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Doughty, C.E., and Goulden, M.L. (2008). Seasonal patterns of tropical forest leaf area index and CO2 exchange. J. Geophys. Res. Biogeosci., 113.","DOI":"10.1029\/2007JG000590"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"972","DOI":"10.1126\/science.aad5068","article-title":"Leaf development and demography explain photosynthetic seasonality in Amazon evergreen forests","volume":"351","author":"Wu","year":"2016","journal-title":"Science"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"405","DOI":"10.1080\/01431168608954695","article-title":"Forestry information content of thematic mapper data","volume":"7","author":"Horler","year":"1986","journal-title":"Int. J. Remote Sens."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"721","DOI":"10.1080\/01431169508954436","article-title":"Estimating the age and structure of forests in a multi-ownership landscape of western Oregon, USA","volume":"16","author":"Cohen","year":"1995","journal-title":"Int. J. Remote Sens."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"118","DOI":"10.1016\/0034-4257(95)00228-6","article-title":"Thematic Mapper characterization of lodgepole pine seral stages in Yellowstone National Park, USA","volume":"56","author":"Jakubauskas","year":"1996","journal-title":"Remote Sens. Environ."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"228","DOI":"10.1016\/j.rse.2006.08.008","article-title":"Predicting temperate conifer forest successional stage distributions with multitemporal landsat thematic mapper imagery","volume":"106","author":"Song","year":"2007","journal-title":"Remote Sens. Environ."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"319","DOI":"10.1016\/0034-4257(94)90006-X","article-title":"Age dependence of forest reflectance: Analysis of main driving factors","volume":"48","author":"Nilson","year":"1994","journal-title":"Remote Sens. Environ."},{"key":"ref_34","unstructured":"Eckenwalder, J.E. (2009). Conifers of the World: The Complete Reference, Timber Press."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"129","DOI":"10.1016\/0168-1923(91)90108-3","article-title":"Evaluation of hemispherical photography for determining plant area index and geometry of a forest stand","volume":"56","author":"Chen","year":"1991","journal-title":"Agric. For. Meteorol."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"103","DOI":"10.1016\/S0168-1923(97)00073-7","article-title":"Calibration of grey values of hemispherical photographs for image analysis","volume":"90","author":"Wagner","year":"1998","journal-title":"Agric. For. Meteorol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1999","DOI":"10.1139\/x00-116","article-title":"Evaluation of digital and film hemispherical photography and spherical densiometry for measuring forest light environments","volume":"30","author":"Englund","year":"2000","journal-title":"Can. J. For. Res."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"17","DOI":"10.1139\/cjfr-2013-0082","article-title":"Improving accuracy of canopy hemispherical photography by a constant threshold value derived from an unobscured overcast sky","volume":"44","author":"Song","year":"2013","journal-title":"Can. J. For. Res."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1007\/s00468-014-1058-2","article-title":"Evaluating optical measurements of leaf area index against litter collection in a mixed broadleaved-Korean pine forest in China","volume":"29","author":"Liu","year":"2015","journal-title":"Trees"},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Ghanem, R., Higdon, D., and Owhadi, H. (2016). Simlab software for uncertainty and sensitivity analysis. Handbook of Uncertainty Quantification, Springer.","DOI":"10.1007\/978-3-319-11259-6"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"466","DOI":"10.1109\/TGRS.1995.8746028","article-title":"Hybrid geometric optical-radiative transfer approach for modeling albedo and directional reflectance of discontinuous canopies","volume":"33","author":"Li","year":"1995","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"987","DOI":"10.1109\/36.752217","article-title":"An analytical hybrid gort model for bidirectional reflectance over discontinuous plant canopies","volume":"37","author":"Ni","year":"1999","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"705","DOI":"10.1109\/TGRS.1985.289389","article-title":"Geometric-optical modeling of a conifer forest canopy","volume":"23","author":"Li","year":"1985","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"906","DOI":"10.1109\/TGRS.1986.289706","article-title":"Geometric-optical bidirectional reflectance modeling of a conifer forest canopy","volume":"24","author":"Li","year":"1986","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"276","DOI":"10.1109\/36.134078","article-title":"Geometric-optical bidirectional reflectance modeling of the discrete crown vegetation canopy: Effect of crown shape and mutual shadowing","volume":"30","author":"Li","year":"1992","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1016\/0146-664X(80)90006-4","article-title":"The boolean model and random sets","volume":"12","author":"Serra","year":"1980","journal-title":"Comput. Graph. Image Process."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"161","DOI":"10.1109\/36.3017","article-title":"Modeling the gap probability of a discontinuous vegetation canopy","volume":"26","author":"Li","year":"1988","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"29555","DOI":"10.1029\/97JD00198","article-title":"Transmission of solar radiation in boreal conifer forests: Measurements and models","volume":"103","author":"Ni","year":"1997","journal-title":"J. Geophys. Res. All Ser."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"285","DOI":"10.1016\/S0034-4257(02)00046-9","article-title":"The spectral\/temporal manifestation of forest succession in optical imagery: The potential of multitemporal imagery","volume":"82","author":"Song","year":"2002","journal-title":"Remote Sens. Environ."},{"key":"ref_50","first-page":"1","article-title":"The characters of leaf area and net photosynthesis efficiency of needle at different parts and in different leaf age of Cunninghamia lanceolata","volume":"41","author":"Zhongkun","year":"2008","journal-title":"Hunan For. Sci. Technol."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"445","DOI":"10.1016\/S0167-9473(97)00043-1","article-title":"An alternative way to compute fourier amplitude sensitivity test (FAST)","volume":"26","author":"Saltelli","year":"1998","journal-title":"Comput. Stat. Data Anal."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"40","DOI":"10.1016\/j.rse.2016.06.008","article-title":"Consistent estimation of multiple parameters from MODIS top of atmosphere reflectance data using a coupled soil-canopy-atmosphere radiative transfer model","volume":"184","author":"Shi","year":"2016","journal-title":"Remote Sens. Environ."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"259","DOI":"10.1016\/j.cpc.2009.09.018","article-title":"Variance based sensitivity analysis of model output. Design and estimator for the total sensitivity index","volume":"181","author":"Saltelli","year":"2010","journal-title":"Comput. Phys. Commun."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1080\/00401706.1999.10485594","article-title":"A quantitative model-independent method for global sensitivity analysis of model output","volume":"41","author":"Saltelli","year":"1999","journal-title":"Technometrics"},{"key":"ref_55","first-page":"398","article-title":"Sensitivity analysis in practice","volume":"101","author":"Saltelli","year":"2004","journal-title":"J. Am. Stat. Assoc."},{"key":"ref_56","first-page":"161","article-title":"Uncertainty and sensitivity matrix of parameters in inversion of physical BRDF model","volume":"1","author":"Li","year":"1997","journal-title":"J. Remote Sens."},{"key":"ref_57","doi-asserted-by":"crossref","unstructured":"Tarantola, A. (2005). Inverse Problem Theory and Methods for Model Parameter Estimation, Society for Industrial and Applied Mathematics (SIAM).","DOI":"10.1137\/1.9780898717921"},{"key":"ref_58","unstructured":"Nocedal, J., and Wright, S.J. (2006). Sequential Quadratic Programming, Springer."},{"key":"ref_59","first-page":"520","article-title":"Changes in spectral properties of leaves as related to chlorophyll content and age of papaya","volume":"16","author":"Lin","year":"1982","journal-title":"Photosynthetica"},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"315","DOI":"10.1007\/s004680050157","article-title":"Spectral changes with leaf aging in Amazon caatinga","volume":"12","author":"Roberts","year":"1998","journal-title":"Trees"},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"176","DOI":"10.1016\/0034-4257(94)90154-6","article-title":"High-spectral resolution field and laboratory optical reflectance measurements of red spruce and eastern hemlock needles and branches","volume":"47","author":"Rock","year":"1994","journal-title":"Remote Sens. Environ."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"194","DOI":"10.2134\/agronj1973.00021962006500020003x","article-title":"Reflectance discrimination of cotton and corn at four growth stages","volume":"65","author":"Gausman","year":"1973","journal-title":"Agron. J."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"1049","DOI":"10.1111\/nph.13853","article-title":"Leaf aging of Amazonian canopy trees as revealed by spectral and physiochemical measurements","volume":"214","author":"Chavanabryant","year":"2017","journal-title":"New Phytol."},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1111\/j.1469-8137.2010.03516.x","article-title":"MODIS enhanced vegetation index data do not show greening of Amazon forests during the 2005 drought","volume":"189","author":"Samanta","year":"2011","journal-title":"New Phytol."},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"1093","DOI":"10.1126\/science.1199048","article-title":"Comment on drought-induced reduction in global terrestrial net primary production from 2000 through 2009","volume":"333","author":"Samanta","year":"2011","journal-title":"Science"},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"490","DOI":"10.1029\/2011GL046824","article-title":"Widespread decline in greenness of Amazonian vegetation due to the 2010 drought","volume":"38","author":"Xu","year":"2011","journal-title":"Geophys. Res. Lett."},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"1787","DOI":"10.1016\/j.rse.2009.04.002","article-title":"The influence of epiphylls on remote sensing of humid forests","volume":"113","author":"Toomey","year":"2009","journal-title":"Remote Sens. Environ."},{"key":"ref_68","first-page":"19","article-title":"Seasonal changes and daily courses of photosynthetic characteristics of 18-year-old chinese fir shoots in relation to shoot ages and positions within tree crown","volume":"36","author":"Xiaoquan","year":"2000","journal-title":"Sci. Silvae Sin."},{"key":"ref_69","doi-asserted-by":"crossref","first-page":"4814","DOI":"10.1111\/gcb.13725","article-title":"The phenology of leaf quality and its within-canopy variation are essential for accurate modeling of photosynthesis in tropical evergreen forests","volume":"23","author":"Wu","year":"2017","journal-title":"Glob. Chang. Biol."},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"249","DOI":"10.1016\/S0168-1923(01)00274-X","article-title":"A comparison of digital and film fisheye photography for analysis of forest canopy structure and gap light transmission","volume":"109","author":"Frazer","year":"2001","journal-title":"Agric. For. Meteorol."},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"166","DOI":"10.1016\/j.agrformet.2005.09.009","article-title":"Determining digital hemispherical photograph exposure for leaf area index estimation","volume":"133","author":"Zhang","year":"2005","journal-title":"Agric. For. Meteorol."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/10\/2\/262\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T14:54:13Z","timestamp":1760194453000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/10\/2\/262"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,2,8]]},"references-count":71,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2018,2]]}},"alternative-id":["rs10020262"],"URL":"https:\/\/doi.org\/10.3390\/rs10020262","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2018,2,8]]}}}