{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T02:22:38Z","timestamp":1760235758662,"version":"build-2065373602"},"reference-count":42,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2021,9,19]],"date-time":"2021-09-19T00:00:00Z","timestamp":1632009600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004020","name":"Japan Aerospace Exploration Agency","doi-asserted-by":"publisher","award":["ER2GWF102"],"award-info":[{"award-number":["ER2GWF102"]}],"id":[{"id":"10.13039\/501100004020","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001691","name":"Japan Society for the Promotion of Science","doi-asserted-by":"publisher","award":["18H03800","21H01430"],"award-info":[{"award-number":["18H03800","21H01430"]}],"id":[{"id":"10.13039\/501100001691","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>The detection of global land change via satellite observation is a major challenge in improving the understanding of global environmental change. In this study, we develop a new vegetation index which can be used as a proxy for the fractions of tree canopy and short vegetation, based on the simple linear regression between microwave vegetation optical depth (VOD) and optical leaf area index (LAI). Although we use no high-resolution reference data, the newly developed vegetation index successfully detects global land change which has been reported by previous estimations based on high-resolution reference data. We find that the relationship between VOD and LAI is non-stationary and the temporal change in the VOD-LAI relationship is an important signal for detecting global change in the terrestrial ecosystem.<\/jats:p>","DOI":"10.3390\/rs13183756","type":"journal-article","created":{"date-parts":[[2021,9,21]],"date-time":"2021-09-21T22:35:20Z","timestamp":1632263720000},"page":"3756","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Global Change in Terrestrial Ecosystem Detected by Fusion of Microwave and Optical Satellite Observations"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9250-3462","authenticated-orcid":false,"given":"Hideharu","family":"Nara","sequence":"first","affiliation":[{"name":"Department of Civil Engineering, The University of Tokyo, Tokyo 113-8656, Japan"}]},{"given":"Yohei","family":"Sawada","sequence":"additional","affiliation":[{"name":"Institute of Engineering Innovation, The University of Tokyo, Tokyo 113-8656, Japan"}]}],"member":"1968","published-online":{"date-parts":[[2021,9,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"927","DOI":"10.3390\/rs5020927","article-title":"Global Data Sets of Vegetation Leaf Area Index (LAI)3g and Fraction of Photosynthetically Active Radiation (FPAR)3g Derived from Global Inventory Modeling and Mapping Studies (GIMMS) Normalized Difference Vegetation Index (NDVI3g) for the Period 1981 to 2011","volume":"5","author":"Zhu","year":"2013","journal-title":"Remote Sens."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"4485","DOI":"10.1080\/01431160500168686","article-title":"An extended AVHRR 8-km NDVI dataset compatible with MODIS and SPOT vegetation NDVI data","volume":"26","author":"Tucker","year":"2005","journal-title":"Int. J. Remote Sens."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"639","DOI":"10.1038\/s41586-018-0411-9","article-title":"Global land change from 1982 to 2016","volume":"560","author":"Song","year":"2018","journal-title":"Nature"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"e2020JG005698","DOI":"10.1029\/2020JG005698","article-title":"Reconstructing the Seasonality and Trend in Global Leaf Area Index During 2001\u20132017 for Prognostic Modeling","volume":"125","author":"Wang","year":"2020","journal-title":"J. Geophys. Res. Biogeosci."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1643","DOI":"10.1109\/36.942542","article-title":"A methodology for surface soil moisture and vegetation optical depth retrieval using the microwave polarization difference index","volume":"39","author":"Owe","year":"2001","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1102","DOI":"10.1016\/j.rse.2010.12.015","article-title":"Satellite passive microwave remote sensing for monitoring global land surface phenology","volume":"115","author":"Jones","year":"2011","journal-title":"Remote Sens. Environ."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"470","DOI":"10.1038\/nclimate2581","article-title":"Recent reversal in loss of global terrestrial biomass","volume":"5","author":"Liu","year":"2015","journal-title":"Nat. Clim. Chang."},{"key":"ref_8","first-page":"86","article-title":"Widespread decline of Congo rainforest greenness in the past decade","volume":"509","author":"Zhou","year":"2014","journal-title":"Nat. Cell Biol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"3111","DOI":"10.1111\/gcb.12288","article-title":"Satellite microwave detection of boreal forest recovery from the extreme 2004 wildfires in Alaska and Canada","volume":"19","author":"Jones","year":"2013","journal-title":"Glob. Chang. Biol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1040","DOI":"10.1002\/wrcr.20123","article-title":"The Millennium Drought in southeast Australia (2001\u20132009): Natural and human causes and implications for water resources, ecosystems, economy, and society","volume":"49","author":"Beck","year":"2013","journal-title":"Water Resour. Res."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"2312","DOI":"10.1002\/2016JG003356","article-title":"Ecosystem resilience to the Millennium drought in southeast Australia (2001\u20132009)","volume":"121","author":"Sawada","year":"2016","journal-title":"J. Geophys. Res. Biogeosci."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1748","DOI":"10.1111\/gcb.13464","article-title":"Mapping gains and losses in woody vegetation across global tropical drylands","volume":"23","author":"Tian","year":"2016","journal-title":"Glob. Chang. Biol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1029\/2007JF000769","article-title":"Multisensor historical climatology of satellite-derived global land surface moisture","volume":"113","author":"Owe","year":"2008","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1029\/2011GL048684","article-title":"Global long-term passive microwave satel-lite-based retrievals of vegetation optical depth","volume":"38","author":"Liu","year":"2011","journal-title":"Geophys. Res. Lett."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"767","DOI":"10.1002\/2016JG003640","article-title":"New data-driven estimation of terrestrial CO2 fluxes in Asia using a standardized database of eddy co-variance measurements, remote sensing data, and support vector regression","volume":"122","author":"Ichii","year":"2017","journal-title":"J. Geophys. Res. Biogeosci."},{"key":"ref_16","unstructured":"Myneni, R., Knyazikhin, Y., and Park, T. (2021, September 19). MOD15A2H MODIS\/Terra Leaf Area Index\/FPAR 8-Day L4 Global 500m SIN Grid V006, Distributed by NASA EOSDIS Land Processes DAAC, Available online: https:\/\/lpdaac.usgs.gov\/products\/mod15a2hv006\/."},{"key":"ref_17","unstructured":"Friedl, M., and Sulla-Menashe, D. (2021, September 16). MCD12C1 MODIS\/Terra+Aqua Land Cover Type Yearly L3 Global 0.05Deg CMG V006. Distributed by NASA EOSDIS Land Processes DAAC. Available online: https:\/\/doi.org\/10.5067\/MODIS\/MCD12C1.006."},{"key":"ref_18","unstructured":"Hansen, M., and Song, X. (2020, December 24). Vegetation Continuous Fields (VCF) Yearly Global 0.05 Deg [Data set]. NASA EOSDIS Land Processes DAAC. Available online: https:\/\/doi.org\/10.5067\/MEaSUREs\/VCF\/VCF5KYR.001."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"6195","DOI":"10.1109\/TGRS.2017.2722468","article-title":"Fusing Microwave and Optical Satellite Observations to Sim-ultaneously Retrieve Surface Soil Moisture, Vegetation Water Content, and Surface Soil Roughness","volume":"55","author":"Sawada","year":"2017","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2082","DOI":"10.1109\/TGRS.2015.2495365","article-title":"A field verification of an algorithm for retrieving veg-etation water content from passive microwave observations","volume":"54","author":"Sawada","year":"2016","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Sawada, Y., Tsutsui, H., and Koike, T. (2017). Ground Truth of Passive Microwave Radiative Transfer on Vegetated Land Surfaces. Remote Sens., 9.","DOI":"10.3390\/rs9070655"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"5734","DOI":"10.3390\/rs70505734","article-title":"Global-Scale Evaluation of Roughness Effects on C-Band AMSR-E Observations","volume":"7","author":"Wang","year":"2015","journal-title":"Remote Sens."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"190","DOI":"10.1016\/j.rse.2005.10.017","article-title":"Vegetation and surface roughness effects on AMSR-E land observations","volume":"100","author":"Njoku","year":"2006","journal-title":"Remote Sens. Environ."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"203","DOI":"10.1016\/0034-4257(91)90057-D","article-title":"Vegetation effects on the microwave emission of soils","volume":"36","author":"Jackson","year":"1991","journal-title":"Remote Sens. Environ."},{"key":"ref_25","unstructured":"O\u2019Neill, P., Bindlish, R., Chan, S., Chaubell, J., Njoku, N., and Jackson, T. (2021, April 26). Algorithm Theoretical Basis Document Level 2 & 3 Soil Moisture (Passive) Data Products, Available online: https:\/\/smap.jpl.nasa.gov\/documents\/."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"617","DOI":"10.1109\/36.7687","article-title":"Microwave polarization index for monitoring vegetation growth","volume":"26","author":"Paloscia","year":"1988","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1456","DOI":"10.1109\/JSTARS.2015.2398034","article-title":"Optical Sensing of Vegetation Water Content: A Synthesis Study","volume":"8","author":"Gao","year":"2015","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"177","DOI":"10.5194\/essd-12-177-2020","article-title":"The global long-term microwave Vegetation Optical Depth Climate Archive (VODCA)","volume":"12","author":"Moesinger","year":"2020","journal-title":"Earth Syst. Sci. Data"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"4568","DOI":"10.1109\/TGRS.2015.2402204","article-title":"Intercalibration of Advanced Microwave Scanning Radiometer-2 (AMSR2) Brightness Temperature","volume":"53","author":"Okuyama","year":"2015","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"932","DOI":"10.1175\/JHM-D-13-0200.1","article-title":"A Preliminary Study toward Consistent Soil Moisture from AMSR2","volume":"16","author":"Parinussa","year":"2015","journal-title":"J. Hydrometeorol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"791","DOI":"10.5194\/essd-9-791-2017","article-title":"A global satellite environment data record derived from AMSR-E and AMSR2 microwave Earth observations","volume":"9","author":"Du","year":"2017","journal-title":"Earth Syst. Sci. Data"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"0081","DOI":"10.1038\/s41559-017-0081","article-title":"Human population growth offsets climate-driven increase in woody vegetation in sub-Saharan Africa","volume":"1","author":"Brandt","year":"2017","journal-title":"Nat. Ecol. Evol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"21415","DOI":"10.1029\/2005GL024370","article-title":"Precipitation controls Sahel greening trend","volume":"32","author":"Hickler","year":"2005","journal-title":"Geophys. Res. Lett."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"28","DOI":"10.1016\/j.rse.2014.11.027","article-title":"Eastern Europe\u2019s forest cover dynamics from 1985 to 2012 quantified from the full Landsat archive","volume":"159","author":"Potapov","year":"2015","journal-title":"Remote Sens. Environ."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"850","DOI":"10.1126\/science.1244693","article-title":"High-Resolution Global Maps of 21st-Century Forest Cover Change","volume":"342","author":"Hansen","year":"2013","journal-title":"Science"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1601","DOI":"10.1111\/gcb.12795","article-title":"Detection and attribution of vegetation greening trend in China over the last 30 years","volume":"21","author":"Piao","year":"2015","journal-title":"Glob. Chang. Biol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"78","DOI":"10.1016\/j.gloplacha.2014.07.005","article-title":"History of land use in India during 1880\u20132010: Large-scale land transfor-mations reconstructed from satellite data and historical archives","volume":"121","author":"Tian","year":"2014","journal-title":"Glob. Planet. Change"},{"key":"ref_38","first-page":"282","article-title":"Improvement of the AMSR-E algorithm for soil moisture estimation by introducing a fractional vegetation coverage dataset derived from MODIS data","volume":"29","author":"Fujii","year":"2009","journal-title":"J. Remote Sens. Soc. Japan"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"229","DOI":"10.2151\/jmsj.85A.229","article-title":"Auto-calibration System De-veloped to Assimilate AMSR-E Data into a Land Surface Model for Estimating Soil Moisture and the Surface Energy Budget","volume":"85A","author":"Yang","year":"2007","journal-title":"J. Meteorol. Soc. Jpn."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"780","DOI":"10.1175\/2008JHM1065.1","article-title":"Validation of a Dual-Pass Microwave Land Data Assimilation System for Es-timating Surface Soil Moisture in Semiarid Regions","volume":"10","author":"Yang","year":"2009","journal-title":"J. Hydrometeorol."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"8839","DOI":"10.1002\/2014JD021536","article-title":"Simultaneous estimation of both hydrological and ecological parameters in an ecohydrological model by assimilating microwave signal","volume":"119","author":"Sawada","year":"2014","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"5910","DOI":"10.1002\/2014JD022895","article-title":"A land data assimilation system for simultaneous simulation of soil moisture and vegetation dynamics","volume":"120","author":"Sawada","year":"2015","journal-title":"J. Geophys. Res. Atmos."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/18\/3756\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T07:02:14Z","timestamp":1760166134000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/18\/3756"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,9,19]]},"references-count":42,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2021,9]]}},"alternative-id":["rs13183756"],"URL":"https:\/\/doi.org\/10.3390\/rs13183756","relation":{},"ISSN":["2072-4292"],"issn-type":[{"type":"electronic","value":"2072-4292"}],"subject":[],"published":{"date-parts":[[2021,9,19]]}}}