Leaf aging of Amazonian canopy trees as revealed by spectral and physiochemical measurements
© 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.
| Veröffentlicht in: | The New phytologist. - 1979. - 214(2017), 3 vom: 01. Mai, Seite 1049-1063 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2017
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| Zugriff auf das übergeordnete Werk: | The New phytologist |
| Schlagworte: | Journal Article canopy trees leaf age leaf lifecycle leaf spectral properties leaf traits phenology tropical forests vegetation indices (VIs) |
| Zusammenfassung: | © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust. Leaf aging is a fundamental driver of changes in leaf traits, thereby regulating ecosystem processes and remotely sensed canopy dynamics. We explore leaf reflectance as a tool to monitor leaf age and develop a spectra-based partial least squares regression (PLSR) model to predict age using data from a phenological study of 1099 leaves from 12 lowland Amazonian canopy trees in southern Peru. Results demonstrated monotonic decreases in leaf water (LWC) and phosphorus (Pmass ) contents and an increase in leaf mass per unit area (LMA) with age across trees; leaf nitrogen (Nmass ) and carbon (Cmass ) contents showed monotonic but tree-specific age responses. We observed large age-related variation in leaf spectra across trees. A spectra-based model was more accurate in predicting leaf age (R2 = 0.86; percent root mean square error (%RMSE) = 33) compared with trait-based models using single (R2 = 0.07-0.73; %RMSE = 7-38) and multiple (R2 = 0.76; %RMSE = 28) predictors. Spectra- and trait-based models established a physiochemical basis for the spectral age model. Vegetation indices (VIs) including the normalized difference vegetation index (NDVI), enhanced vegetation index 2 (EVI2), normalized difference water index (NDWI) and photosynthetic reflectance index (PRI) were all age-dependent. This study highlights the importance of leaf age as a mediator of leaf traits, provides evidence of age-related leaf reflectance changes that have important impacts on VIs used to monitor canopy dynamics and productivity and proposes a new approach to predicting and monitoring leaf age with important implications for remote sensing |
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| Beschreibung: | Date Completed 16.02.2018 Date Revised 16.03.2022 published: Print-Electronic CommentIn: New Phytol. 2017 May;214(3):903-904. - PMID 28397361 Citation Status MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1111/nph.13853 |