Impact of Structural, Photochemical and Instrumental Effects on Leaf and Canopy Reflectance Variability in the 500–600 nm Range

Remote Sensing

Adrián Moncholi-Estornell¹  Maria Pilar Cendrero-Mateo¹  Shari Van Wittenberghe¹  Luis Alonso¹  José Moreno¹  Zbyněk Malenovský² 

[1] Laboratory of Earth Observation, Image Processing Laboratory, University of Valencia, 46980 Paterna, Spain;School of Geography, Planning, and Spatial Sciences, College of Sciences Engineering and Technology, University of Tasmania, Private Bag 76, Hobart, TAS 7001, Australia;

关键词: proximal sensing;    spectroscopy;    protocols;    irradiance;    reflectance;    vegetation index;   

DOI  :  10.3390/rs14010056

来源: DOAJ

【 摘 要 】

Current rapid technological improvement in optical radiometric instrumentation provides an opportunity to develop innovative measurements protocols where the remote quantification of the plant physiological status can be determined with higher accuracy. In this study, the leaf and canopy reflectance variability in the PRI spectral region (i.e., 500–600 nm) is quantified using different laboratory protocols that consider both instrumental and experimental set-up aspects, as well as canopy structural effects and vegetation photoprotection dynamics. First, we studied how an incorrect characterization of the at-target incoming radiance translated into an erroneous vegetation reflectance spectrum and consequently in an incorrect quantification of reflectance indices such as PRI. The erroneous characterization of the at-target incoming radiance translated into a 2% overestimation and a 31% underestimation of estimated chlorophyll content and PRI-related vegetation indexes, respectively. Second, we investigated the dynamic xanthophyll pool and intrinsic Chl vs. Car long-term pool changes affecting the entire 500–600 nm spectral region. Consistent spectral behaviors were observed for leaf and canopy experiments. Sun-adapted plants showed a larger optical change in the PRI range and a higher capacity for photoprotection during the light transient time when compared to shade-adapted plants. Outcomes of this work highlight the importance of well-established spectroscopy sampling protocols to detect the subtle photochemical features which need to be disentangled from the structural and biological effects.

【 授权许可】

Unknown