Exploring the potential of MODIS EVI for modeling gross primary production across African ecosystems

M. Sjöström, J. Ardö, A. Arneth, E.M. Veenendaal

Research output: Contribution to journalArticleAcademicpeer-review

99 Citations (Scopus)

Abstract

One of the most frequently applied methods for integrating controls on primary production through satellite data is the light use efficiency (LUE) approach, which links vegetation gross or net primary productivity (GPP or NPP) to remotely sensed estimates of absorbed photosynthetically active radiation (APAR). Eddy covariance towers provide continuous measurements of carbon flux, presenting an opportunity for evaluation of satellite estimates of GPP. Here we investigate relationships between eddy covariance estimated GPP, environmental variables derived from flux towers, Moderate Resolution Imaging Spectroradiometer (MODIS) enhanced vegetation index (EVI) and GPP across African savanna ecosystems. MODIS GPP was found to underestimate GPP at the majority of sites, particularly at sites in the Sahel. EVI was found to correlate well with estimated GPP on a site-by-site basis. Combining EVI with tower-measured PAR and evaporative fraction (EF, a measure of water sufficiency) improved the direct relationship between GPP and EVI at the majority of the sites. The slope of this relationship was strongly related to site peak leaf area index (LAI). These results are promising for the extension of GPP through the use of remote sensing data to a regional or even continental scale. Research Highlights ¿ We explore relationships between GPP and MODIS data for sites across Africa. ¿ We assess the MODIS GPP product and whether MODIS EVI can be used for GPP modelling. ¿ We find that MODIS GPP underestimates GPP and that EVI is correlated with GPP. ¿ Including PAR and a water index (EF) improved relationships between GPP and EVI. ¿ We conclude that EVI, PAR, EF and LAI can be used to accurately model GPP at sites. Keywords: Africa; Gross primary production (GPP); Moderate Resolution Imaging Spectroradiometer (MODIS); Enhanced vegetation index (EVI); Evaporative fraction (EF); Leaf area index (LAI)
Original languageEnglish
Pages (from-to)1081-1089
JournalRemote Sensing of Environment
Volume115
Issue number4
DOIs
Publication statusPublished - 2011

Keywords

  • leaf-area index
  • eddy covariance technique
  • radiation use efficiency
  • carbon-dioxide exchange
  • satellite sensor data
  • southern africa
  • time-series
  • seasonal-variation
  • solar-radiation
  • energy fluxes

Fingerprint

Dive into the research topics of 'Exploring the potential of MODIS EVI for modeling gross primary production across African ecosystems'. Together they form a unique fingerprint.

Cite this