TY - JOUR
T1 - Global and time-resolved monitoring of crop photosynthesis with chlorophyll fluorescence
AU - Guanter, Luis
AU - Zhang, Yongguang
AU - Jung, Martin
AU - Joiner, Joanna
AU - Voigt, Maximilian
AU - Berry, Joseph A.
AU - Frankenberg, Christian
AU - Huete, Alfredo R.
AU - Zarco-Tejada, Pablo
AU - Lee, Jung Eun
AU - Moran, M. Susan
AU - Ponce-Campos, Guillermo
AU - Beer, Christian
AU - Camps-Valls, Gustavo
AU - Buchmann, Nina
AU - Gianelle, Damiano
AU - Klumpp, Katja
AU - Cescatti, Alessandro
AU - Baker, John M.
AU - Griffis, Timothy J.
PY - 2014
Y1 - 2014
N2 - Photosynthesis is the process by which plants harvest sunlight to produce sugars from carbon dioxide and water. It is the primary source of energy for all life on Earth; hence it is important to understand how this process responds to climate change and human impact. However, model-based estimates of gross primary production (GPP, output from photosynthesis) are highly uncertain, in particular over heavily managed agricultural areas. Recent advances in spectroscopy enable the space-based monitoring of sun-induced chlorophyll fluorescence (SIF) from terrestrial plants. Here we demonstrate that spaceborne SIF retrievals provide a direct measure of the GPP of cropland and grassland ecosystems. Such a strong link with crop photosynthesis is not evident for traditional remotely sensed vegetation indices, nor for more complex carbon cycle models. We use SIF observations to provide a global perspective on agricultural productivity. Our SIF-based crop GPP estimates are 50-75% higher than results from state-ofthe- art carbon cycle models over, for example, the US Corn Belt and the Indo-Gangetic Plain, implying that current models severely underestimate the role of management. Our results indicate that SIF data can help us improve our global models for more accurate projections of agricultural productivity and climate impact on crop yields. Extension of our approach to other ecosystems, along with increased observational capabilities for SIF in the near future, holds the prospect of reducing uncertainties in the modeling of the current and future carbon cycle.
AB - Photosynthesis is the process by which plants harvest sunlight to produce sugars from carbon dioxide and water. It is the primary source of energy for all life on Earth; hence it is important to understand how this process responds to climate change and human impact. However, model-based estimates of gross primary production (GPP, output from photosynthesis) are highly uncertain, in particular over heavily managed agricultural areas. Recent advances in spectroscopy enable the space-based monitoring of sun-induced chlorophyll fluorescence (SIF) from terrestrial plants. Here we demonstrate that spaceborne SIF retrievals provide a direct measure of the GPP of cropland and grassland ecosystems. Such a strong link with crop photosynthesis is not evident for traditional remotely sensed vegetation indices, nor for more complex carbon cycle models. We use SIF observations to provide a global perspective on agricultural productivity. Our SIF-based crop GPP estimates are 50-75% higher than results from state-ofthe- art carbon cycle models over, for example, the US Corn Belt and the Indo-Gangetic Plain, implying that current models severely underestimate the role of management. Our results indicate that SIF data can help us improve our global models for more accurate projections of agricultural productivity and climate impact on crop yields. Extension of our approach to other ecosystems, along with increased observational capabilities for SIF in the near future, holds the prospect of reducing uncertainties in the modeling of the current and future carbon cycle.
KW - Carbon fluxes
KW - Carbon modeling
KW - Crop productivity
KW - Earth observation
KW - Spaceborne spectroscopy
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U2 - 10.1073/pnas.1320008111
DO - 10.1073/pnas.1320008111
M3 - Article
C2 - 24706867
AN - SCOPUS:84898024828
SN - 0027-8424
VL - 111
SP - E1327-E1333
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 14
ER -