Name
Title | ||
|---|---|---|
Diurnal Changes in Leaf Photochemical Reflectance Index in Two Evergreen Forest Canopies |
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 biomes—a 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
<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Manilkara elata</italic>
leaves was correlated with the average photosynthetic photon flux density (PPFD) (
<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$R^{2}=0.59$</tex-math></inline-formula>
,
<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$p< 0.01$</tex-math></inline-formula>
) of the 40 minutes preceding the leaf measurement. In the boreal location, the variations in
<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Pinus sylvestris</italic>
needle PRI were only weakly (
<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$R^{2}=0.27$</tex-math></inline-formula>
,
<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$p< 0.05$</tex-math></inline-formula>
) correlated with mean PPFD of the preceding two hours; for
<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Betula pendula</italic>
, the correlation was insignificant (
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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. |
Year | DOI | Venue |
|---|---|---|
2019 | 10.1109/jstars.2019.2891789 | IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing |
Keywords | Field | DocType |
Forestry,Extraterrestrial measurements,Needles,Sea measurements,Indexes,Vegetation mapping,Poles and towers | Vegetation,Photosynthesis,Evergreen,Remote sensing,Taiga,Atmospheric sciences,Evergreen forest,Photochemical Reflectance Index,Boreal,Mathematics,Solar time | Journal |
Volume | Issue | ISSN |
12 | 7 | 1939-1404 |
Citations | PageRank | References |
0 | 0.34 | 0 |
Authors | ||
9 | ||
Name | Order | Citations | PageRank |
|---|---|---|---|
| Matti Mõttus | 1 | 37 | 8.84 |
| Luiz Eduardo O. C. de Aragão | 2 | 49 | 19.87 |
| Jaana Back | 3 | 0 | 0.34 |
| Rocío Hernández-Clemente | 4 | 23 | 4.77 |
| Eduardo E. Maeda | 5 | 23 | 6.73 |
| Vincent Markiet | 6 | 4 | 1.48 |
| Caroline J. Nichol | 7 | 31 | 4.87 |
| Raimundo Cosme de Oliveira | 8 | 0 | 0.68 |
| Natalia Restrepo Coupe | 9 | 11 | 2.28 |