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Decoupling of greenness and gross primary productivity as aridity decreases

Journal Article · · Remote Sensing of Environment
 [1];  [2];  [3];  [2];  [2];  [4];  [5];  [6];  [6];  [7];  [8];  [9];  [10]
  1. South China Normal University (SCNU), Guangzhou (China); Hainan University, Haikou (China); Southern Marine Science and Engineering Guangdong Laboratory (China)
  2. Peking Univ., Beijing (China)
  3. Colorado State Univ., Fort Collins, CO (United States)
  4. Sun Yat-Sen Univ., Guangzhou (China); Southern Marine Science and Engineering Guangdong Laboratory (China)
  5. Univ. of Montana, Missoula, MT (United States)
  6. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  7. Laboratoire des Sciences du Climatet de l’Environnement, Gif-sur-Yvette (France)
  8. Northern Arizona Univ., Flagstaff, AZ (United States)
  9. Oklahoma State Univ., Stillwater, OK (United States)
  10. Chinese Academy of Sciences (CAS), Beijing (China)

Ecosystem primary productivity is a key ecological process influencing many ecosystem services, including carbon storage. Thus, clarifying how primary productivity in terrestrial ecosystems responds to climatic variability can reveal key mechanisms that will drive future changes in the global carbon budget. Satellite products of canopy greenness are widely used as proxies for vegetation productivity to evaluate how ecosystems respond to climate variability. However, to what degree inter-annual variations in productivity are consistent with greenness and how this relationship varies spatially remains unclear. Here we investigated the strength of the coupling between inter-annual variations in leaf area index (LAI, a measure of greenness) and ecosystem gross primary productivity (GPP) derived from eddy covariance towers, i.e., the r2 of the LAI-GPP relationship. Overall, inter-annual GPP and LAI were highly coupled (i.e., high r2) in arid grasslands, but were fully decoupled in mesic evergreen broadleaf forests, indicating that this relationship varies strongly along aridity gradients. A possible mechanism of the spatial variation in the LAI-GPP relationship is that the tradeoff between ecosystem structure (LAI) and physiology (photosynthesis per unit leaf area) becomes stronger in more humid climates. Land models overestimated the r2 of LAI-GPP correlation for most ecosystem types and failed to capture the spatial pattern along aridity gradients. We conclude that relying on greenness products for evaluating inter-annual changes in vegetation productivity may bias assessments, especially in tropical rainforest ecosystems. Our findings may also reconcile observed disparities between responses in greenness and GPP during drought in Amazon forests.

Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Biological and Environmental Research (BER); National Natural Science Foundation of China; National Key R&D Program of China; Second Tibetan Plateau Scientific Expedition and Research Program
Grant/Contract Number:
AC05-00OR22725
OSTI ID:
1876255
Journal Information:
Remote Sensing of Environment, Journal Name: Remote Sensing of Environment Journal Issue: 1 Vol. 279; ISSN 0034-4257
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English

References (31)

Spatiotemporal patterns of terrestrial gross primary production: A review: GPP Spatiotemporal Patterns journal August 2015
Inter-annual variability of net and gross ecosystem carbon fluxes: A review journal February 2018
TIMESAT—a program for analyzing time-series of satellite sensor data journal October 2004
Assessing the ability of MODIS EVI to estimate terrestrial ecosystem gross primary production of multiple land cover types journal January 2017
MODIS Collection 5 global land cover: Algorithm refinements and characterization of new datasets journal January 2010
Satellite-derived LAI products exhibit large discrepancies and can lead to substantial uncertainty in simulated carbon and water fluxes journal March 2018
Amazon forests did not green-up during the 2005 drought: AMAZON DROUGHT SENSITIVITY journal March 2010
Widespread decline in greenness of Amazonian vegetation due to the 2010 drought: BROWNING OF AMAZONIA IN THE 2010 DROUGHT journal April 2011
Satellite Observations of the Contrasting Response of Trees and Grasses to Variations in Water Availability journal February 2019
Drought impact on forest carbon dynamics and fluxes in Amazonia journal March 2015
Dry-season greening of Amazon forests journal March 2016
Reduction in carbon uptake during turn of the century drought in western North America journal July 2012
Characteristics, drivers and feedbacks of global greening journal December 2019
Severe summer heatwave and drought strongly reduced carbon uptake in Southern China journal January 2016
Vegetation dynamics and rainfall sensitivity of the Amazon journal October 2014
Effect of increasing CO 2 on the terrestrial carbon cycle journal December 2014
Light-driven growth in Amazon evergreen forests explained by seasonal variations of vertical canopy structure journal February 2017
Mechanistic evidence for tracking the seasonality of photosynthesis with solar-induced fluorescence journal May 2019
Satellite remote sensing of primary production journal November 1986
Satellite observations of high northern latitude vegetation productivity changes between 1982 and 2008: ecological variability and regional differences journal October 2011
Evaluation of terrestrial carbon cycle models for their response to climate variability and to CO 2 trends journal April 2013
Amazon drought and forest response: Largely reduced forest photosynthesis but slightly increased canopy greenness during the extreme drought of 2015/2016 journal February 2018
Joint structural and physiological control on the interannual variation in productivity in a temperate grassland: A data-model comparison journal May 2018
Interannual variation of terrestrial carbon cycle: Issues and perspectives journal November 2019
Drought impacts on the Amazon forest: the remote sensing perspective: Research review journal June 2010
FLUXNET: A New Tool to Study the Temporal and Spatial Variability of Ecosystem–Scale Carbon Dioxide, Water Vapor, and Energy Flux Densities journal November 2001
Global Data Sets of Vegetation Leaf Area Index (LAI)3g and Fraction of Photosynthetically Active Radiation (FPAR)3g Derived from Global Inventory Modeling and Mapping Studies (GIMMS) Normalized Difference Vegetation Index (NDVI3g) for the Period 1981 to 2011 journal February 2013
A global spatially contiguous solar-induced fluorescence (CSIF) dataset using neural networks journal January 2018
Scaling carbon fluxes from eddy covariance sites to globe: synthesis and evaluation of the FLUXCOM approach journal January 2020
Global carbon budget 2013 journal January 2014
The North American Carbon Program Multi-Scale Synthesis and Terrestrial Model Intercomparison Project – Part 1: Overview and experimental design journal January 2013