Terrestrial carbon balance in tropical Asia: Contribution from cropland expansion and land management

Bo Tao, Hanqin Tian, Guangsheng Chen, Wei Ren, Chaoqun Lu, Kelly D. Alley, Xiaofeng Xu, Mingliang Liu, Shufen Pan, Hassan Virji

Research output: Contribution to journalArticlepeer-review

37 Scopus citations

Abstract

Tropical Asia has experienced dramatic cropland expansion and agricultural intensification to meet the increasing food demand and is likely to undergo further rapid development in the near future. Much concern has been raised about how cropland expansion and associated management practices (nitrogen fertilizer use, irrigation, etc.) have affected the terrestrial carbon cycle in this region. In this study, we used a process-based ecosystem model, the Dynamic Land Ecosystem Model (DLEM), to assess the magnitude, spatial and temporal patterns of terrestrial carbon fluxes and pools in Tropical Asia as resulted from cropland expansion and land management practices during 1901-2005. The results indicated that cropland expansion had resulted in a release of 19.12 ± 3.06. Pg. C (0.18 ± 0.029. Pg. C/yr) into the atmosphere in Tropical Asia over the study period. Of this amount, approximately 22% (4.18 ± 0.66. Pg. C) was released from South Asia and 78% (14.94 ± 2.40. Pg. C) from Southeast Asia. Larger land area was converted to cropland while less carbon was emitted from South Asia than from Southeast Asia, where forest biomass and soil carbon were significantly higher. Changes in vegetation, soil organic matter, and litter pools caused emissions of 15.58, 2.25, and 1.71. Pg. C, respectively, from the entire region. Significant decreases in vegetation carbon occurred across most regions of Southeast Asia due to continuous cropland expansion and shrink of natural forests. When considering land management practices, however, less carbon was released into the atmosphere, especially in South Asia where land management practices contributed to an approximately 10% reduction in carbon emission. This implies that optimizing land management practices could greatly reduce the carbon emissions caused by cropland expansion and might be one of important climate mitigation options in Tropical Asia.

Original languageEnglish
Pages (from-to)85-98
Number of pages14
JournalGlobal and Planetary Change
Volume100
DOIs
StatePublished - Jan 2013

Bibliographical note

Funding Information:
This study has been funded by NASA LCLUC Program ( NNX08AL73G_S01 ) and Auburn University Peak of Excellence Program . We thank Kamaljit Banger for constructive suggestion.

Keywords

  • Carbon storage
  • Cropland expansion
  • Land management
  • Tropical Asia
  • Tropical deforestation

ASJC Scopus subject areas

  • Global and Planetary Change
  • Oceanography

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