{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,28]],"date-time":"2026-02-28T06:01:15Z","timestamp":1772258475137,"version":"3.50.1"},"posted":{"date-parts":[[2018,3,29]]},"group-title":"Biogeophysics: Environmental Optics","reference-count":0,"publisher":"Copernicus GmbH","license":[{"start":{"date-parts":[[2018,3,29]],"date-time":"2018-03-29T00:00:00Z","timestamp":1522281600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["PTDC\/AAG-MAA\/3699\/2014"],"award-info":[{"award-number":["PTDC\/AAG-MAA\/3699\/2014"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"abstract":"<jats:p>Abstract. We applied an empirical modelling approach for Gross Primary Productivity (GPP) estimation from hyperspectral surface reflectance of Mediterranean grasslands undergoing different fertilization treatments. The objective of the study was to identify combinations of vegetation indices and bands that better represent GPP changes between the annual-peak of growth and senescence dry out in Mediterranean grasslands. In situ, hyperspectral measurements of vegetation reflectance, were collected at the same time as CO2 gas exchange measurements were performed in control (C) and fertilized plots with added nitrogen (N), phosphorus (P) or the combination of N, P and potassium (NPK). Reflectance values were aggregated, according to their similarity (r\u2009&gt;\u200990\u2009%), in 26 continuous wavelength intervals (Hyp). Also, the same reflectance values were resampled reproducing the wavebands of both Sentinel-2A Multispectral Instrument (S2) and Landsat 8 Operation Land Imager (L8). This lead to a set of reflectance values simulating the signal that would be captured in ideal conditions by either Sentinel-2A or Landsat 8. The LEAPS procedure was applied to select the best set of the vegetation indices or spectral bands for GPP estimation using Hyp, S2 or L8. The LEAPS selected some vegetation indices putting in evidence their exploratory power as indicators of the dynamic changes of community vegetation properties such as canopy water content (NDWI) or chlorophyll and carotenoids\/chlorophyll ratio (MTCI, PSRI, GNDVI), underlining their importance for grasslands GPP estimates.  For Hyp and S2, spectral bands showed similar exploratory power than vegetation indices to estimate GPP. A two-step LEAPS procedure allowed us also to identify spectral bands with potential for improving GPP estimates. This procedure clearly indicates the shortwave infrared region of the spectra as promising for this purpose. The comparison of S2 and L8 based models showed similar explanatory power of the two simulated satellite sensors when spectral bands were adopted. Altogether our results show the potential of sensors on board of Sentinel 2 and Landsat 8 satellites for monitoring grasslands phenology and improving GPP estimates in support of a sustainable agriculture management.<\/jats:p>","DOI":"10.5194\/bg-2018-110","type":"posted-content","created":{"date-parts":[[2018,3,29]],"date-time":"2018-03-29T02:53:40Z","timestamp":1522292020000},"source":"Crossref","is-referenced-by-count":1,"title":["On estimating Gross Primary Productivity of Mediterranean grasslands under different fertilization regimes using vegetation indices and hyperspectral reflectance"],"prefix":"10.5194","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9118-193X","authenticated-orcid":false,"given":"Sofia","family":"Cerasoli","sequence":"first","affiliation":[]},{"given":"Manuel","family":"Campagnolo","sequence":"additional","affiliation":[]},{"given":"Joana","family":"Faria","sequence":"additional","affiliation":[]},{"given":"Carla","family":"Nogueira","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3586-8526","authenticated-orcid":false,"given":"Maria","family":"Caldeira","sequence":"additional","affiliation":[]}],"member":"3145","container-title":[],"original-title":[],"link":[{"URL":"https:\/\/www.biogeosciences-discuss.net\/bg-2018-110\/bg-2018-110.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,2,1]],"date-time":"2025-02-01T10:43:15Z","timestamp":1738406595000},"score":1,"resource":{"primary":{"URL":"https:\/\/bg.copernicus.org\/articles\/15\/5455\/2018\/bg-15-5455-2018-discussion.html"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,3,29]]},"references-count":0,"URL":"https:\/\/doi.org\/10.5194\/bg-2018-110","relation":{"has-comment":[{"id-type":"doi","id":"10.5194\/bg-2018-110-AC1","asserted-by":"subject"},{"id-type":"doi","id":"10.5194\/bg-2018-110-AC3","asserted-by":"subject"},{"id-type":"doi","id":"10.5194\/bg-2018-110-AC2","asserted-by":"subject"}],"has-review":[{"id-type":"doi","id":"10.5194\/bg-2018-110-RC1","asserted-by":"subject"},{"id-type":"doi","id":"10.5194\/bg-2018-110-RC2","asserted-by":"subject"}],"is-preprint-of":[{"id-type":"doi","id":"10.5194\/bg-15-5455-2018","asserted-by":"subject"},{"id-type":"doi","id":"10.5194\/bg-15-5455-2018","asserted-by":"object"}]},"subject":[],"published":{"date-parts":[[2018,3,29]]},"subtype":"preprint"}}