{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,8]],"date-time":"2026-02-08T08:26:49Z","timestamp":1770539209806,"version":"3.49.0"},"reference-count":35,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2019,9,13]],"date-time":"2019-09-13T00:00:00Z","timestamp":1568332800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Key Research Program of Frontier Sciences of the Chinese Academy of Sciences","award":["QYZDB-SSW-DQC025"],"award-info":[{"award-number":["QYZDB-SSW-DQC025"]}]},{"name":"Creative Research Groups of National Natural Science Foundation of China","award":["41621061"],"award-info":[{"award-number":["41621061"]}]},{"name":"Top-Notch Young Talents Program of China","award":["41571103"],"award-info":[{"award-number":["41571103"]}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["41861134038"],"award-info":[{"award-number":["41861134038"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>As an important land-surface parameter, vegetation phenology has been estimated from observations by various satellite-borne sensors with substantially different spatial resolutions, ranging from tens of meters to several kilometers. The inconsistency of satellite-derived phenological metrics (e.g., green-up date, GUD, also known as the land-surface spring phenology) among different spatial resolutions, which is referred to as the \u201cscale effect\u201d on GUD, has been recognized in previous studies, but it still needs further efforts to explore the cause of the scale effect on GUD and to quantify the scale effect mechanistically. To address these issues, we performed mathematical analyses and designed up-scaling experiments. We found that the scale effect on GUD is not only related to the heterogeneity of GUD among fine pixels within a coarse pixel, but it is also greatly affected by the covariation between the GUD and vegetation growth speed of fine pixels. GUD of a coarse pixel tends to be closer to that of fine pixels with earlier green-up and higher vegetation growth speed. Therefore, GUD of the coarse pixel is earlier than the average of GUD of fine pixels, if the growth speed is a constant. However, GUD of the coarse pixel could be later than the average from fine pixels, depending on the proportion of fine pixels with later GUD and higher growth speed. Based on those mechanisms, we proposed a model that accounted for the effects of heterogeneity of GUD and its co-variation with growth speed, which explained about 60% of the scale effect, suggesting that the model can help convert GUD estimated at different spatial scales. Our study provides new mechanistic explanations of the scale effect on GUD.<\/jats:p>","DOI":"10.3390\/rs11182137","type":"journal-article","created":{"date-parts":[[2019,9,13]],"date-time":"2019-09-13T10:32:41Z","timestamp":1568370761000},"page":"2137","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":40,"title":["How Does Scale Effect Influence Spring Vegetation Phenology Estimated from Satellite-Derived Vegetation Indexes?"],"prefix":"10.3390","volume":"11","author":[{"given":"Licong","family":"Liu","sequence":"first","affiliation":[{"name":"State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8122-9696","authenticated-orcid":false,"given":"Ruyin","family":"Cao","sequence":"additional","affiliation":[{"name":"School of Resources and Environment, University of Electronic Science and Technology of China, 2006 Xiyuan Avenue, West Hi-tech Zone, Chengdu 611731, China"}]},{"given":"Miaogen","family":"Shen","sequence":"additional","affiliation":[{"name":"Key Laboratory of Alpine Ecology, Institute of Tibetan Plateau Research, CAS Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, 16 Lincui Road, Beijing 100101, China"}]},{"given":"Jin","family":"Chen","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6739-9499","authenticated-orcid":false,"given":"Jianmin","family":"Wang","sequence":"additional","affiliation":[{"name":"Geospatial Sciences Center of Excellence, Department of Geography and Geospatial Sciences, South Dakota State University, Brookings, SD 57007, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8456-0547","authenticated-orcid":false,"given":"Xiaoyang","family":"Zhang","sequence":"additional","affiliation":[{"name":"Geospatial Sciences Center of Excellence, Department of Geography and Geospatial Sciences, South Dakota State University, Brookings, SD 57007, USA"}]}],"member":"1968","published-online":{"date-parts":[[2019,9,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"295","DOI":"10.1111\/j.1469-8137.2004.01059.x","article-title":"Responses of spring phenology to climate change","volume":"162","author":"Badeck","year":"2004","journal-title":"New Phytol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1805","DOI":"10.1016\/j.rse.2010.04.005","article-title":"Land surface phenology from MODIS: Characterization of the Collection 5 global land cover dynamics product","volume":"114","author":"Ganguly","year":"2010","journal-title":"Remote Sens. Environ."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1506","DOI":"10.1002\/2017JG003811","article-title":"Comparisons of Global Land Surface Seasonality and Phenology Derived from AVHRR, MODIS and VIIRS Data: Phenology from AVHRR, MODIS and VIIRS","volume":"122","author":"Zhang","year":"2017","journal-title":"J. Geophys. Res. Biogeosci."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"71","DOI":"10.1016\/j.agrformet.2014.01.003","article-title":"Increasing altitudinal gradient of spring vegetation phenology during the last decade on the Qinghai\u2013Tibetan Plateau","volume":"89\u2013190","author":"Shen","year":"2014","journal-title":"Agric. For. Meteorol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"318","DOI":"10.1016\/j.rse.2017.01.001","article-title":"Exploration of scaling effects on coarse resolution land surface phenology","volume":"190","author":"Zhang","year":"2017","journal-title":"Remote Sens. Environ."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1016\/j.isprsjprs.2017.09.002","article-title":"Scaling effects on spring phenology detections from MODIS data at multiple spatial resolutions over the contiguous United States","volume":"132","author":"Peng","year":"2017","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"207","DOI":"10.1016\/j.agrformet.2018.03.010","article-title":"Scaling up spring phenology derived from remote sensing images","volume":"256\u2013257","author":"Peng","year":"2018","journal-title":"Agric. For. Meteorol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"68","DOI":"10.1016\/S0034-4257(98)00067-4","article-title":"Monitoring phenological key stages and cycle duration of temporate deciduous forest ecosystems with NOAA\/AVHRR data","volume":"67","author":"Duchemin","year":"1999","journal-title":"Remote Sens. Environ."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"3451","DOI":"10.1080\/014311699211499","article-title":"Surface phenology and satellite sensor-derived onset of greenness: An initial comparison","volume":"20","author":"Schwartz","year":"1999","journal-title":"Int. J. Remote Sens."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"687","DOI":"10.1002\/joc.4013","article-title":"NDVI and vegetation phenology dynamics under the influence of sunshine duration on the Tibetan plateau","volume":"35","author":"Wang","year":"2015","journal-title":"Int. J. Climatol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"338","DOI":"10.1016\/j.rse.2018.04.030","article-title":"The mixed pixel effect in land surface phenology: A simulation study","volume":"211","author":"Chen","year":"2018","journal-title":"Remote Sens. Environ."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"261","DOI":"10.1016\/j.rse.2007.01.004","article-title":"Cross-scalar satellite phenology from ground, Landsat, and MODIS data","volume":"109","author":"Fisher","year":"2007","journal-title":"Remote Sens. Environ."},{"key":"ref_13","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_14","doi-asserted-by":"crossref","first-page":"233","DOI":"10.1016\/0034-4257(95)00156-5","article-title":"Scaling and uncertainty in the relationship between the NDVI and land surface biophysical variables: An analysis using a scene simulation model and data from FIFE","volume":"54","author":"Friedl","year":"1995","journal-title":"Remote Sens. Environ."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"326","DOI":"10.1109\/36.134082","article-title":"Upscale integration of normalized difference vegetation index: The problem of spatial heterogeneity","volume":"30","author":"Aman","year":"1992","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1303","DOI":"10.1080\/01431169508954478","article-title":"NOAA-AVHRR NDVI decomposition and subpixel classification using linear mixing in the Argentinean Pampa","volume":"16","author":"Kerdiles","year":"1995","journal-title":"Int. J. Remote Sens."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"167","DOI":"10.1016\/j.rse.2017.07.020","article-title":"xThe relationship between threshold-based and inflexion-based approaches for extraction of land surface phenology","volume":"199","author":"Shang","year":"2017","journal-title":"Remote Sens. Environ."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"2618","DOI":"10.1016\/j.rse.2009.07.020","article-title":"Influence of heterogeneous landscapes on computed green-up dates based on daily AVHRR NDVI observations","volume":"113","author":"Doktor","year":"2009","journal-title":"Remote Sens. Environ."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"180028","DOI":"10.1038\/sdata.2018.28","article-title":"Tracking vegetation phenology across diverse North American biomes using PhenoCam imagery","volume":"5","author":"Richardson","year":"2018","journal-title":"Sci. Data"},{"key":"ref_20","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_21","first-page":"1478","article-title":"Tracking forest phenology and seasonal physiology using digital repeat photography: A critical assessment","volume":"24","author":"Keenan","year":"2016","journal-title":"Ecol. Appl. A Publ. Ecol. Soc. Am."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.rse.2017.04.031","article-title":"A snow-free vegetation index for improved monitoring of vegetation spring green-up date in deciduous ecosystems","volume":"196","author":"Wang","year":"2017","journal-title":"Remote Sens. Environ."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"661","DOI":"10.1023\/A:1008107902848","article-title":"Landscape patterns simulation with a modified random clusters method","volume":"15","author":"Saura","year":"2000","journal-title":"Landsc. Ecol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"3833","DOI":"10.1016\/j.rse.2008.06.006","article-title":"Development of a two-band enhanced vegetation index without a blue band","volume":"112","author":"Jiang","year":"2008","journal-title":"Remote Sens. Environ."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1016\/j.rse.2010.08.013","article-title":"Validating satellite phenology through intensive ground observation and landscape scaling in a mixed seasonal forest","volume":"115","author":"Liang","year":"2011","journal-title":"Remote Sens. Environ."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"277","DOI":"10.1126\/science.329.5989.277-e","article-title":"Warming, Photoperiods, and Tree Phenology","volume":"329","author":"Chuine","year":"2010","journal-title":"Science"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"176","DOI":"10.1016\/j.agrformet.2017.11.032","article-title":"Modeling vegetation green-up dates across the Tibetan Plateau by including both seasonal and daily temperature and precipitation","volume":"249","author":"Cao","year":"2018","journal-title":"Agric. For. Meteorol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"650","DOI":"10.1016\/j.agrformet.2016.10.021","article-title":"Little change in heat requirement for vegetation green-up on the Tibetan Plateau over the warming period of 1998\u20132012","volume":"232","author":"Cong","year":"2017","journal-title":"Agric. For. Meteorol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"693","DOI":"10.2307\/2404093","article-title":"Date of budburst of 15 tree species in Britain following climatic warming","volume":"26","author":"Murray","year":"1989","journal-title":"J. Appl. Ecol."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"25460","DOI":"10.1038\/srep25460","article-title":"Plant phenological synchrony increases under rapid within-spring warming","volume":"6","author":"Wang","year":"2016","journal-title":"Sci. Rep."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"3707","DOI":"10.1002\/joc.4227","article-title":"Temperature sensitivity as an explanation of the latitudinal pattern of green-up date trend in Northern Hemisphere vegetation during 1982\u20132008","volume":"35","author":"Shen","year":"2015","journal-title":"Int. J. Climatol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1016\/j.agrformet.2014.09.009","article-title":"An improved logistic method for detecting spring vegetation phenology in grasslands from MODIS EVI time-series data","volume":"200","author":"Cao","year":"2015","journal-title":"Agric. For. Meteorol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1016\/0034-4257(88)90043-0","article-title":"Soil and atmosphere influences on the spectra of partial canopies","volume":"25","author":"Huete","year":"1988","journal-title":"Remote Sens. Environ."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Ding, Y., Zheng, X., Kai, Z., Xin, X., and Liu, H. (2016). Quantifying the Impact of NDVIsoil Determination Methods and NDVIsoil Variability on the Estimation of Fractional Vegetation Cover in Northeast China. Remote Sens., 8.","DOI":"10.3390\/rs8010029"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"244","DOI":"10.1016\/j.rse.2018.08.022","article-title":"A simple method to improve the quality of NDVI time-series data by integrating spatiotemporal information with the Savitzky-Golay filter","volume":"217","author":"Cao","year":"2018","journal-title":"Remote Sens. Environ."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/11\/18\/2137\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T13:19:55Z","timestamp":1760188795000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/11\/18\/2137"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,9,13]]},"references-count":35,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2019,9]]}},"alternative-id":["rs11182137"],"URL":"https:\/\/doi.org\/10.3390\/rs11182137","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,9,13]]}}}