Terrestrial carbon sinks in the Brazilian Amazon and Cerrado region predicted from MODIS satellite data and ecosystem modeling

C Potter,M Bustamante,V Genovese,A Huete,S Klooster,L Guimaraes Ferreira,R Zepp

doi:10.5194/bg-6-937-2009

Abstract

Abstract. A simulation model based on satellite observations of monthly vegetation cover from the Moderate Resolution Imaging Spectroradiometer (MODIS) was used to estimate monthly carbon fluxes in terrestrial ecosystems of Brazilian Amazon and Cerrado regions over the period 2000–2004. Net ecosystem production (NEP) flux for atmospheric CO2 in the region for these years was estimated. Consistently high carbon sink fluxes in terrestrial ecosystems on a yearly basis were found in the western portions of the states of Acre and Rondônia and the northern portions of the state of Pará. These areas were not significantly impacted by the 2002–2003 El Niño event in terms of net annual carbon gains. Areas of the region that show periodically high carbon source fluxes from terrestrial ecosystems to the atmosphere on yearly basis were found throughout the state of Maranhão and the southern portions of the state of Amazonas. As demonstrated though tower site comparisons, NEP modeled with monthly MODIS Enhanced Vegetation Index (EVI) inputs closely resembles the measured seasonal carbon fluxes at the LBA Tapajos tower site. Modeling results suggest that the capacity for use of MODIS Enhanced Vegetation Index (EVI) data to predict seasonal uptake rates of CO2 in Amazon forests and Cerrado woodlands is strong.

Highlights

Carbon dioxide (CO2) is a major contributor to the planetary greenhouse effect and potential climate change
We present the results of CASA (Carnegie Ames Stanford Approach) model predictions of terrestrial ecosystem fluxes using 2000–2004 Moderate Resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) inputs at 8km spatial resolution
– Areas of the region that show consistently high carbon sink fluxes in terrestrial ecosystems on a yearly basis are the western portions of the states of Acre and Rondonia and the northern portions of the state of Para

Summary

Introduction

Carbon dioxide (CO2) is a major contributor to the planetary greenhouse effect and potential climate change. Several previous studies of ecosystem modeling, namely Kindermann et al (1996), Potter et al (1998), Tian et al (1998), Prentice and Lloyd (1998), Asner et al (2000), Houghton et al (2000), Potter et al (2001), and Foley et al (2002), have examined how variations in climate affect the carbon balance of the Amazon basin Most of these models suggested that the net annual flux of carbon by the basin is significantly correlated to El Nino Southern Oscillation (ENSO) events. The Amazon basin was predicted to be a significant carbon sink during La Nina events, and a carbon source during El Nino events These modeling studies published before most data from the LBA project was generated concluded that major variations in the regional carbon balance are related to changes in precipitation. In southern Amazonia, both recent El Nino and La Nina periods have been drier than neutral conditions

Methods

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Discussion

Conclusion