{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,11]],"date-time":"2026-07-11T15:34:09Z","timestamp":1783784049752,"version":"3.55.0"},"reference-count":70,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2017,1,7]],"date-time":"2017-01-07T00:00:00Z","timestamp":1483747200000},"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>Long-term observations of vegetation phenology can be used to monitor the response of terrestrial ecosystems to climate change. Satellite remote sensing provides the most efficient means to observe phenological events through time series analysis of vegetation indices such as the Normalized Difference Vegetation Index (NDVI). This study investigates the potential of a Photochemical Reflectance Index (PRI), which has been linked to vegetation light use efficiency, to improve the accuracy of MODIS-based estimates of phenology in an evergreen conifer forest. Timings of the start and end of the growing season (SGS and EGS) were derived from a 13-year-long time series of PRI and NDVI based on a MAIAC (multi-angle implementation of atmospheric correction) processed MODIS dataset and standard MODIS NDVI product data. The derived dates were validated with phenology estimates from ground-based flux tower measurements of ecosystem productivity. Significant correlations were found between the MAIAC time series and ground-estimated SGS (R2 = 0.36\u20130.8), which is remarkable since previous studies have found it difficult to observe inter-annual phenological variations in evergreen vegetation from satellite data. The considerably noisier NDVI product could not accurately predict SGS, and EGS could not be derived successfully from any of the time series. While the strongest relationship overall was found between SGS derived from the ground data and PRI, MAIAC NDVI exhibited high correlations with SGS more consistently (R2 &gt; 0.6 in all cases). The results suggest that PRI can serve as an effective indicator of spring seasonal transitions, however, additional work is necessary to confirm the relationships observed and to further explore the usefulness of MODIS PRI for detecting phenology.<\/jats:p>","DOI":"10.3390\/rs9010049","type":"journal-article","created":{"date-parts":[[2017,1,9]],"date-time":"2017-01-09T11:03:23Z","timestamp":1483959803000},"page":"49","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":54,"title":["Detecting Inter-Annual Variations in the Phenology of Evergreen Conifers Using Long-Term MODIS Vegetation Index Time Series"],"prefix":"10.3390","volume":"9","author":[{"given":"Laura","family":"Ulsig","sequence":"first","affiliation":[{"name":"School of GeoSciences, Crew Building, University of Edinburgh, Alexander Crum Brown Road, Edinburgh EH9 3FF, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Caroline","family":"Nichol","sequence":"additional","affiliation":[{"name":"School of GeoSciences, Crew Building, University of Edinburgh, Alexander Crum Brown Road, Edinburgh EH9 3FF, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Karl","family":"Huemmrich","sequence":"additional","affiliation":[{"name":"Joint Center for Earth Systems Technology (JCET), University of Maryland Baltimore County, Catonsville, MD 20771, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"David","family":"Landis","sequence":"additional","affiliation":[{"name":"Global Science &amp; Technology, Greenbelt, MD 20770, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Elizabeth","family":"Middleton","sequence":"additional","affiliation":[{"name":"NASA Goddard Space Flight Center, Earth Sciences, Greenbelt, MD 20771, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alexei","family":"Lyapustin","sequence":"additional","affiliation":[{"name":"NASA Goddard Space Flight Center, Earth Sciences, Greenbelt, MD 20771, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8516-3356","authenticated-orcid":false,"given":"Ivan","family":"Mammarella","sequence":"additional","affiliation":[{"name":"Department of Physics, University of Helsinki, P.O. Box 48, Helsinki 00014, Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Janne","family":"Levula","sequence":"additional","affiliation":[{"name":"SMEARII, Hyytia\u0308la\u0308 Forestry Field Station, Deptartment of Physics, University of Helsinki, Hyytia\u0308la\u0308ntie 124, Korkeakoski FI 35500, Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Albert","family":"Porcar-Castell","sequence":"additional","affiliation":[{"name":"Department of Forest Sciences, Viikki Plant Science Center (ViPS), University of Helsinki, P.O. Box 27, Helsinki 00014, Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2017,1,7]]},"reference":[{"key":"ref_1","unstructured":"IPCC (2014). Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part A: Global and Sectoral Aspects. Contribution of Working Group II to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"479","DOI":"10.1046\/j.1365-2486.2003.00629.x","article-title":"Assessing the eddy covariance technique for evaluating carbon dioxide exchange rates of ecosystems: Past, present and future","volume":"9","author":"Baldocchi","year":"2003","journal-title":"Glob. Chang. Biol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1576","DOI":"10.1126\/science.271.5255.1576","article-title":"Exchange of carbon dioxide by a deciduous forest: Response to interannual climate variability","volume":"271","author":"Goulden","year":"1996","journal-title":"Science"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"703","DOI":"10.2307\/3235884","article-title":"Measuring phenological variabilty from satellite imagery","volume":"5","author":"Reed","year":"1994","journal-title":"J. Veg. Sci."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"L04705","DOI":"10.1029\/2004GL021961","article-title":"A global framework for monitoring phenological responses to climate change","volume":"32","author":"White","year":"2005","journal-title":"Geophys. Res. Lett."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"779","DOI":"10.1111\/j.1365-2486.2005.00949.x","article-title":"Land surface phenology and temperature variation in the international geosphere-biosphere program high-latitude transects","volume":"11","author":"Henebry","year":"2005","journal-title":"Glob. Chang. Biol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1007\/s00484-014-0817-5","article-title":"Assessing phenological change and climatic control of alpine grasslands in the Tibetan plateau with MODIS time series","volume":"59","author":"Wang","year":"2014","journal-title":"Int. J. Biometeorol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"20069","DOI":"10.1029\/2000JD000115","article-title":"Variations in northern vegetation activity inferred from satellite data of vegetation index during 1981 to 1999","volume":"106","author":"Zhou","year":"2001","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"290","DOI":"10.1016\/j.rse.2015.12.017","article-title":"Matching the phenology of net ecosystem exchange and vegetation indices estimated with MODIS and FLUXNET in-situ observations","volume":"174","author":"Balzarolo","year":"2016","journal-title":"Remote Sens. Environ."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"625","DOI":"10.1016\/j.rse.2013.09.022","article-title":"MODIS time-series-derived indicators for the beginning of the growing season in boreal coniferous forest\u2014A comparison with CO2 flux measurements and phenological observations in Finland","volume":"140","author":"Aurela","year":"2014","journal-title":"Remote Sens. Environ."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"145","DOI":"10.1016\/j.rse.2013.01.010","article-title":"Evaluation of the potential of MODIS satellite data to predict vegetation phenology in different biomes: An investigation using ground-based NDVI measurements","volume":"132","author":"Hmimina","year":"2013","journal-title":"Remote Sens. Environ."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1016\/0034-4257(79)90013-0","article-title":"Red and photographic infrared linear combinations for monitoring vegetation","volume":"8","author":"Tucker","year":"1979","journal-title":"Remote Sens. Environ."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"214","DOI":"10.1016\/S0034-4257(02)00074-3","article-title":"Global products of vegetation leaf area and fraction absorbed PAR from year one of MODIS data","volume":"83","author":"Myneni","year":"2002","journal-title":"Remote Sens. Environ."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"196","DOI":"10.1111\/nph.13251","article-title":"The photochemical reflectance index provides an optical indicator of spring photosynthetic activation in evergreen conifers","volume":"206","author":"Wong","year":"2015","journal-title":"New Phytol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"253","DOI":"10.1111\/j.1466-8238.2009.00504.x","article-title":"Patterns and controls of the variability of radiation use efficiency and primary productivity across terrestrial ecosystems","volume":"19","author":"Garbulsky","year":"2010","journal-title":"Glob. Ecol. Biogeogr."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"481","DOI":"10.1016\/j.rse.2009.10.003","article-title":"Remote sensing of tundra gross ecosystem productivity and light use efficiency under varying temperature and moisture conditions","volume":"114","author":"Huemmrich","year":"2010","journal-title":"Remote Sens. Environ."},{"key":"ref_17","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_18","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_19","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 efficency","volume":"170","author":"Nichol","year":"2012","journal-title":"Oecologia"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"4149","DOI":"10.5194\/bg-12-4149-2015","article-title":"Monitoring seasonal and diurnal changes in photosynthetic pigments with automated PRI and NDVI sensors","volume":"12","author":"Gamon","year":"2015","journal-title":"Biogeosciences"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"6039","DOI":"10.1073\/pnas.0400168101","article-title":"Drought stress and carbon uptake in an Amazon forest measured with spaceborne imaging spectroscopy","volume":"101","author":"Asner","year":"2004","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Hilker, T., Coops, N.C., Hall, F.G., Nichol, C.J., Lyapustin, A., Black, T.A., Wulder, M.A., Leuning, R., Barr, A., and Hollinger, D.Y. (2011). Inferring terrestrial photosynthetic light use efficiency of temperate ecosystems from space. J. Geophys. Res., 116.","DOI":"10.1029\/2011JG001692"},{"key":"ref_23","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_24","doi-asserted-by":"crossref","first-page":"667","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 Chem. Phys. Meteorol."},{"key":"ref_25","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_26","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_27","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_28","doi-asserted-by":"crossref","first-page":"2860","DOI":"10.1111\/j.1365-2486.2008.01684.x","article-title":"Remote estimation of carbon dioxide uptake by a mediterranean forest","volume":"14","author":"Garbulsky","year":"2008","journal-title":"Glob. Chang. Biol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1101","DOI":"10.1016\/j.rse.2009.02.001","article-title":"Tracking seasonal drought effects on ecosystem light use efficiency with satellite-based PRI in a mediterranean forest","volume":"113","author":"Goerner","year":"2009","journal-title":"Remote Sens. Environ."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"189","DOI":"10.5194\/bg-8-189-2011","article-title":"Remote sensing of ecosystem light use efficiency with MODIS-based PRI","volume":"8","author":"Goerner","year":"2011","journal-title":"Biogeosciences"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"6157","DOI":"10.1080\/01431161.2014.950762","article-title":"The utility of MODIS-sPRI for investigating the photosynthetic light-use efficiency in a mediterranean deciduous forest","volume":"35","author":"Guarini","year":"2014","journal-title":"Int. J. Remote Sens."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"L10503","DOI":"10.1029\/2004GL019778","article-title":"Potential of MODIS ocean bands for estimating CO2 flux from terrestrial vegetation: A novel approach","volume":"31","author":"Rahman","year":"2004","journal-title":"Geophys. Res. Lett."},{"key":"ref_33","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 efficiencies: A review and meta-analysis","volume":"115","author":"Garbulsky","year":"2011","journal-title":"Remote Sens. Environ."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1484","DOI":"10.1111\/j.1365-2486.2007.01352.x","article-title":"Can we measure terrestrial photosynthesis from space directly, using spectral reflectance and fluorescence?","volume":"13","author":"Grace","year":"2007","journal-title":"Glob. Chang. Biol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"195","DOI":"10.1016\/S0034-4257(02)00096-2","article-title":"Overview of the radiometric and biophysical performance of the MODIS indices","volume":"83","author":"Huete","year":"2002","journal-title":"Remote Sens. Environ."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1824","DOI":"10.1109\/TGRS.2002.802519","article-title":"Seasonality extraction by function-fitting to time series of satellite data","volume":"40","author":"Ekhlund","year":"2002","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"400","DOI":"10.1016\/j.rse.2012.04.001","article-title":"Inter-comparison of four models for smoothing satellite sensor time-series data to estimate vegetation phenology","volume":"123","author":"Atkinson","year":"2012","journal-title":"Remote Sens. Environ."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"321","DOI":"10.1016\/j.rse.2005.10.021","article-title":"Improved monitoring of vegetation dynamics at very high latitudes: A new method using MODIS NDVI","volume":"100","author":"Beck","year":"2006","journal-title":"Remote Sens. Environ."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"345","DOI":"10.1016\/j.rse.2016.10.021","article-title":"Remote sensing of ecosystem light use efficiency using MODIS","volume":"187","author":"Middleton","year":"2016","journal-title":"Remote Sens. Environ."},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Lyapustin, A., Wang, Y., Laszlo, I., Kahn, R., Korkin, S., Remer, L., Levy, R., and Reid, J.S. (2011). Multiangle implementation of atmospheric correction (MAIAC): 2. Aerosol algorithm. J. Geophys. Res., 116.","DOI":"10.1029\/2010JD014986"},{"key":"ref_41","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_42","doi-asserted-by":"crossref","first-page":"2463","DOI":"10.1016\/j.rse.2009.07.012","article-title":"An assessment of photosynthetic light use efficiency from space: Modeling the atmospheric and directional impacts on PRI reflectance","volume":"113","author":"Hilker","year":"2009","journal-title":"Remote Sens. Environ."},{"key":"ref_43","first-page":"287","article-title":"Long-term measurements of surface fluxes above a Scots pine forest in Hyytiala, southern Finland, 1996\u20132001","volume":"8","author":"Suni","year":"2003","journal-title":"Boreal Environ. Res."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"225","DOI":"10.1016\/j.rse.2004.07.006","article-title":"Similarities in ground- and satellite-based NDVI time series and their relationship to physiological activity of a scots pine forest in Finland","volume":"93","author":"Wang","year":"2004","journal-title":"Remote Sens. Environ."},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Aubinet, M., Vesala, T., and Papale, D. (2012). Eddy Covariance: A Practical Guide to Measurement and Data Analysis, Springer Science & Business Media.","DOI":"10.1007\/978-94-007-2351-1"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"4915","DOI":"10.5194\/amt-9-4915-2016","article-title":"Quantifying the uncertainty of eddy covariance fluxes due to the use of different software packages and combinations of processing steps in two contrasting ecosystems","volume":"9","author":"Mammarella","year":"2016","journal-title":"Atmos. Meas. Tech."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"1856","DOI":"10.1175\/2009JTECHA1179.1","article-title":"Relative humidity effect on the high frequency attenuation of water vapour flux measured by a closed-path eddy covariance system","volume":"26","author":"Mammarella","year":"2009","journal-title":"J. Atmos. Ocean. Technol."},{"key":"ref_48","first-page":"761","article-title":"CO2 exchange and component CO2 fluxes of a boreal Scots pine forest","volume":"14","author":"Kolari","year":"2009","journal-title":"Boreal Environ. Res."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"277","DOI":"10.1098\/rstb.1977.0140","article-title":"Climate and the efficiency of crop production in Britain","volume":"281","author":"Monteith","year":"1977","journal-title":"Philos. Trans. R. Soc. Lond. Biol."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"248","DOI":"10.1016\/j.rse.2008.09.003","article-title":"Noise reduction of NDVI time series: An empirical comparison of selected techniques","volume":"113","author":"Hird","year":"2009","journal-title":"Remote Sens. Environ."},{"key":"ref_51","doi-asserted-by":"crossref","unstructured":"Eklundh, L., and J\u00f6nsson, P. (2015). Remote Sensing Time Series. TIMESAT: A Software Package for Time-Series Processing and Assessment of Vegetation Dynamics, Springer.","DOI":"10.1007\/978-3-319-15967-6_7"},{"key":"ref_52","unstructured":"Doktor, D., and Lange, M. Phenex Version 1.0.3\u2014Auxiliary Functions for Phenological Data Analysis. Available online: https:\/\/cran.r-project.org\/web\/packages\/phenex\/phenex.pdf."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"1585","DOI":"10.1080\/01431169208904212","article-title":"The Best Index Slope Extraction (BISE): A method for reducing noise in NDVI time-series","volume":"13","author":"Viovy","year":"1992","journal-title":"Int. J. Remote Sens."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"361","DOI":"10.1109\/JSTARS.2010.2075916","article-title":"An enhanced TIMESAT algorithm for estimating vegetation phenology metrics from MODIS data","volume":"4","author":"Tan","year":"2011","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"471","DOI":"10.1016\/S0034-4257(02)00135-9","article-title":"Monitoring vegetation phenology using MODIS","volume":"84","author":"Zhang","year":"2003","journal-title":"Remote Sens. Environ."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"2643","DOI":"10.1016\/j.rse.2007.12.004","article-title":"Evaluation of the onset of green-up in temperate deciduous broadleaf forests derived from moderate resolution imaging spectroradiometer (MODIS) data","volume":"112","author":"Soudani","year":"2008","journal-title":"Remote Sens. Environ."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"1741","DOI":"10.1016\/j.agrformet.2011.07.008","article-title":"A comparison of multiple phenology data sources for estimating seasonal transitions in deciduous forest carbon exchange","volume":"151","author":"Garrity","year":"2011","journal-title":"Agric. For. Meteorol."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"3519","DOI":"10.1080\/01431169408954343","article-title":"A global 1\u00b0 by 1\u00b0 NDVI data set for climate studies. Part 2: The generation of global fields of terrestrial biophysical parameters from the NDVI","volume":"15","author":"Sellers","year":"2007","journal-title":"Int. J. Remote Sens."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"332","DOI":"10.1016\/j.rse.2004.03.014","article-title":"A simple method for reconstructing a high-quality NDVI time-series data set based on the Savitzky\u2013Golay filter","volume":"91","author":"Chen","year":"2004","journal-title":"Remote Sens. Environ."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"1410","DOI":"10.1046\/j.1365-2486.2003.00597.x","article-title":"Air temperature triggers the recovery of evergreen boreal forest photosynthesis in spring","volume":"9","author":"Tanja","year":"2003","journal-title":"Glob. Chang. Biol."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"701","DOI":"10.1111\/j.1600-0889.2009.00441.x","article-title":"Spring initiation and autumn cessation of boreal coniferous forest CO2 exchange assessed by meteorological and biological variables","volume":"61","author":"Thum","year":"2009","journal-title":"Tellus B"},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"152","DOI":"10.1016\/j.rse.2016.01.021","article-title":"Improved modeling of land surface phenology using MODIS land surface reflectance and temperature at evergreen needleleaf forests of central North America","volume":"176","author":"Liu","year":"2016","journal-title":"Remote Sens. Environ."},{"key":"ref_63","first-page":"D16207","article-title":"An automatic cloud mask algorithm based on time series of MODIS measurements","volume":"113","author":"Lyapustin","year":"2008","journal-title":"J. Geophys. Res."},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"156","DOI":"10.1016\/j.agrformet.2012.09.012","article-title":"Climate change, phenology, and phenological control of vegetation feedbacks to the climate system","volume":"169","author":"Richardson","year":"2013","journal-title":"Agric. For. Meteorol."},{"key":"ref_65","first-page":"196","article-title":"The need for a common basis for defining light use efficiency: Implications for productivity estimation","volume":"483","author":"Gitelsen","year":"2015","journal-title":"Pap. Nat. Resour."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"776","DOI":"10.1016\/j.agrformet.2007.11.006","article-title":"Utility of spectral vegetation indices for estimation of light use efficiency in coniferous forests in Japan","volume":"148","author":"Nakaji","year":"2008","journal-title":"Agric. For. Meteorol."},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"82","DOI":"10.1016\/j.rse.2014.04.021","article-title":"Estimation of light use efficiency through a combinational use of the photochemical reflectance index and vapour pressure deficit in an evergreen tropical rainforest at Pasoh, Peninsular Malaysia","volume":"150","author":"Nakaji","year":"2014","journal-title":"Remote Sens. Environ."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"6202","DOI":"10.1080\/01431161.2012.682660","article-title":"In situ examination of the relationship between various vegetation indices and canopy phenology in an evergreen coniferous forest, Japan","volume":"19","author":"Nagai","year":"2012","journal-title":"Int. J. Remote Sens."},{"key":"ref_69","doi-asserted-by":"crossref","first-page":"542","DOI":"10.1111\/j.1600-0889.2007.00262.x","article-title":"Relationship between temperature and the seasonal course of photosynthesis in Scots pine at northern timberline and in southern boreal zone","volume":"59","author":"Kolari","year":"2007","journal-title":"Tellus B"},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"52","DOI":"10.1016\/j.rse.2005.11.012","article-title":"Remote sensing of spring phenology in boreal regions: A free of snow-effect method using NOAA-AVHRR and SPOT-VGT data (1982\u20132004)","volume":"101","author":"Delbart","year":"2006","journal-title":"Remote Sens. Environ."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/9\/1\/49\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T18:25:42Z","timestamp":1760207142000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/9\/1\/49"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,1,7]]},"references-count":70,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2017,1]]}},"alternative-id":["rs9010049"],"URL":"https:\/\/doi.org\/10.3390\/rs9010049","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2017,1,7]]}}}