Analysis of Photosynthetic Activity at the Leaf and Canopy Levels from Reflectance Measurements: A Case Study

Autor:	M. Méthy
Rok vydání:	2000
Předmět:	Canopy chemistry.chemical_classification Photosystem II Physiology Irradiance Eddy covariance Plant Science Biology Photosynthesis Photochemical Reflectance Index Atmospheric sciences chemistry Xanthophyll Botany Chlorophyll fluorescence
Zdroj:	Photosynthetica. 38:505-512
ISSN:	1573-9058 0300-3604
DOI:	10.1023/a:1012449104831
Popis:	The photochemical reflectance index (PRI), based on reflectance signatures at 531 and 570 nm, and associated with xanthophyll pigment inter-conversion and related thylakoid energisation, was evaluated as an indicator of photosynthetic function in a Mediterranean holm oak (Quercus ilex L.) coppice. The chlorophyll fluorescence pulse-amplitude-modulation and the eddy correlation techniques were used to estimate the photosystem 2 photochemical efficiency of leaves and the CO2 flux over the canopy, respectively. The reflectance and fluorescence techniques yielded identical estimates of the photosynthetic activity in leaves exposed to dark-light-dark cycles or to a variable irradiance in laboratory. However, there was no such correlation between photosynthetic performance and PRI when applied to a sun-exposed canopy in field conditions. Fluorescence profiles inside the canopy and especially a helpful use of multispectral reflectance imaging highlight the limitations of such method.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::03b80ce7c8956e37f70ec491d391075b https://doi.org/10.1023/a:1012449104831 Zobrazit plný text záznamu Full text from SpringerLink