Soil carbon dynamics and carbon budget of newly reconstructed tall-grass prairies in south central Iowa

J Environ Qual. 2009 Dec 30;39(1):136-46. doi: 10.2134/jeq2009.0063. Print Jan-Feb 2010.

Abstract

In addition to their aesthetic and environmental qualities, reconstructed prairies can act as C sinks and potentially offset rising atmospheric CO(2) concentration. The objective of this study was to quantify C budget components of newly established prairies on previously cultivated land. Net ecosystem production (NEP) was estimated using a C budgeting approach that assessed SOC content, soil surface CO(2)-C emission, and above- and belowground plant biomass. Study was conducted in southern Iowa, in 2005 to 2007. Results show that differences between sites for potential total C input were primarily due to root biomass contributions, which ranged from 0.8 to 5.4 Mg C ha(-1). Average potential aboveground biomass C input was 2.7 Mg C ha(-1) in 2006 and 5.5 Mg C ha(-1) in 2007. Total soil CO(2)-C emissions from heterotrophic respiration increased as prairie age increased from 2.9 to 4.0 Mg C ha(-1) and 3.1 to 4.7 Mg C ha(-1) in 2006 and 2007, respectively. Determination of NEP showed that the 1998 and 2003 reconstructed prairie sites had the greatest potential for soil C sequestration at 4.1 and 4.4 Mg C ha(-1). Increases in SOC content were only observed in the youngest established prairie site (2003) and the no-till site in 2003 at 2.1 and 2.6 Mg C ha(-1) yr(-1), respectively. Declines of SOC sequestration rates occurred when potential C equilibrium was reached (R(h) = NPP) within 10 yr since prairie establishment.

MeSH terms

  • Biomass
  • Carbon / chemistry*
  • Carbon / metabolism*
  • Conservation of Natural Resources
  • Ecosystem*
  • Environmental Monitoring
  • Iowa
  • Nitrogen
  • Poaceae / metabolism*
  • Soil / analysis*
  • Time Factors

Substances

  • Soil
  • Carbon
  • Nitrogen