TY - JOUR
T1 - A remotely sensed pigment index reveals photosynthetic phenology in evergreen conifers
AU - Gamon, John A.
AU - Huemmrich, K. Fred
AU - Wong, Christopher Y.S.
AU - Ensminger, Ingo
AU - Garrity, Steven
AU - Hollinger, David Y.
AU - Noormets, Asko
AU - Peñuelask, Josep
N1 - Funding Information:
We thank Dave Landis (GST, Inc.) for MODIS data processing. J.A.G. was supported by the Alberta Informatics Circle of Research Excellence/Alberta Innovates Technology Futures (Grants G224150012 and 200700172), Natural Sciences and Engineering Research Council (NSERC) (Grant RGPIN-2015-05129), Canada Foundation for Innovation (CFI) (Grant 26793), and NASA Arctic-Boreal Vulnerability Experiment (Grant NNX15AT78A). K.F.H. was supported by the NASA Science of Aqua and Terra program (Grant NNX14AJ65G). I.E. was supported by the NSERC (Grant RGPIN-2015-06514), CFI (Grant 27330), and Ontario Ministry of Research and Innovation (Grant ER10-07-015). J.P. was supported by European Research Council Synergy Grant SyG-2013-610028 IMBALANCE-P. Data and logistical support for the Wind River site were provided by the US Forest Service (FS) Pacific Northwest Research Station and the University of Washington (Grant 11-JV-11261952-030). Support for the Howland Forest AmeriFlux core site was provided by the US Department of Energy (DOE)'s Office of Science and the US Department of Agriculture (USDA) Forest Service Northern Research Station. The work at the Parker Tract, NC (USNC2) site was supported by USDA FS Eastern Forest Environmental Threat Assessment Center Cooperative Agreements 03-CA-11330147-073 and 04-CA-11330147-238, DOE-National Institute for Climate Change Research (NICCR) Award 08-SC-NICCR-1072, Department of the Interior (DOI) Southeast Climate Science Center Award G10AC00624, DOE Terrestrial Ecosystem Science Award 11-DE-SC-0006700, and USDA NIFA Awards 2011-68002-30185 and 2014-67003-22068.
PY - 2016/11/15
Y1 - 2016/11/15
N2 - In evergreen conifers, where the foliage amount changes little with season, accurate detection of the underlying "photosynthetic phenology" from satellite remote sensing has been difficult, presenting challenges for global models of ecosystem carbon uptake. Here, we report a close correspondence between seasonally changing foliar pigment levels, expressed as chlorophyll/carotenoid ratios, and evergreen photosynthetic activity, leading to a "chlorophyll/carotenoid index" (CCI) that tracks evergreen photosynthesis at multiple spatial scales. When calculated from NASA's Moderate Resolution Imaging Spectroradiometer satellite sensor, the CCI closely follows the seasonal patterns of daily gross primary productivity of evergreen conifer stands measured by eddy covariance. This discovery provides a way of monitoring evergreen photosynthetic activity from optical remote sensing, and indicates an important regulatory role for carotenoid pigments in evergreen photosynthesis. Improved methods of monitoring photosynthesis from space can improve our understanding of the global carbon budget in a warming world of changing vegetation phenology.
AB - In evergreen conifers, where the foliage amount changes little with season, accurate detection of the underlying "photosynthetic phenology" from satellite remote sensing has been difficult, presenting challenges for global models of ecosystem carbon uptake. Here, we report a close correspondence between seasonally changing foliar pigment levels, expressed as chlorophyll/carotenoid ratios, and evergreen photosynthetic activity, leading to a "chlorophyll/carotenoid index" (CCI) that tracks evergreen photosynthesis at multiple spatial scales. When calculated from NASA's Moderate Resolution Imaging Spectroradiometer satellite sensor, the CCI closely follows the seasonal patterns of daily gross primary productivity of evergreen conifer stands measured by eddy covariance. This discovery provides a way of monitoring evergreen photosynthetic activity from optical remote sensing, and indicates an important regulatory role for carotenoid pigments in evergreen photosynthesis. Improved methods of monitoring photosynthesis from space can improve our understanding of the global carbon budget in a warming world of changing vegetation phenology.
KW - CCI
KW - Carotenoid pigments
KW - Chlorophyll/carotenoid index
KW - Evergreen conifers
KW - Gross primary productivity
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U2 - 10.1073/pnas.1606162113
DO - 10.1073/pnas.1606162113
M3 - Article
C2 - 27803333
AN - SCOPUS:84995542990
SN - 0027-8424
VL - 113
SP - 13087
EP - 13092
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 - 46
ER -