@Article{MottusABHMMNOR:2019:DiChLe,
author = "Mottus, Matti and Arag{\~a}o, Luiz Eduardo Oliveira e Cruz de and
Back, Jaana and Hernandez-Clemente, Rocio and Maeda, Eduardo Eiji
and Markiet, Vincent and Nichol, Caroline and Oliveira, Raimundo
Cosme de and Restrepo-Coupe, Natalia",
affiliation = "{Tartu Observatory} and {Instituto Nacional de Pesquisas Espaciais
(INPE)} and {University of Helsinki} and {Swansea University} and
{University of Helsinki} and {University of Helsinki} and
{University of Edinburgh} and {Embrapa Amazonia Oriental} and
{University of Arizona}",
title = "Diurnal changes in leaf photochemical reflectance index in two
evergreen forest canopies",
journal = "IEEE Journal of Selected Topics in Applied Earth Observations and
Remote Sensing",
year = "2019",
volume = "00",
pages = "1--8",
keywords = "Amazon rainforest, Betula pendula, boreal forest, light use
efficiency, Manilkara elata, photochemical reflectance index
(PRI), Pinus sylvestris.",
abstract = "The spectral properties of plant leaves relate to the state of
their photosynthetic apparatus and the surrounding environment. An
example is the well known photosynthetic downregulation, active on
the time scale from minutes to hours, caused by reversible changes
in the xanthophyll cycle pigments. These changes affect leaf
spectral absorption and are frequently quantified using the
photochemical reflectance index (PRI). This index can be used to
remotely monitor the photosynthetic status of vegetation, and
allows for a global satellite-based measurement of photosynthesis.
Such earth observation satellites in near-polar orbits usually
cover the same geographical location at the same local solar time
at regular intervals. To facilitate the interpretation of these
instantaneous remote PRI measurements and upscale them temporally,
we measured the daily course of leaf PRI in two evergreen biomesa
European boreal forest and an Amazon rainforest. The daily course
of PRI was different for the two locations: At the Amazonian
forest, the PRI of Manilkara elata leaves was correlated with the
average photosynthetic photon flux density (PPFD) (R2 = 0.59, p <
0.01) of the 40 minutes preceding the leaf measurement. In the
boreal location, the variations in Pinus sylvestris needle PRI
were only weakly (R2 = 0.27, p < 0.05) correlated with mean PPFD
of the preceding two hours; for Betula pendula, the correlation
was insignificant (p > 0.5) regardless of the averaging period.
The measured daily PRI curves were specific to species and/or
environmental conditions. Hence, for a proper interpretation of
satellite-measured instantaneous photosynthesis, the scaling of
PRI measurements should be supported with information on its
correlation with PPFD.",
doi = "10.1109/JSTARS.2019.2891789",
url = "http://dx.doi.org/10.1109/JSTARS.2019.2891789",
issn = "1939-1404 and 2151-1535",
label = "lattes: 5174466549126882 2 MottusABHMMNOR:2019:DiChLe",
language = "pt",
targetfile = "08642393.pdf",
urlaccessdate = "27 abr. 2024"
}