Soil carbon dynamics and carbon budget of newly reconstructed tall-grass prairies in south central Iowa.
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.
Guzman
Jose G
JG
Dep. of Agronomy, Iowa State Univ., Ames, IA 50011-1010, USA.
Al-Kaisi
Mahdi M
MM
D018533:Biomass; D002244:Carbon / Q000737:chemistry* / Q000378:metabolism*; D003247:Conservation of Natural Resources; D017753:Ecosystem; D004784:Environmental Monitoring; D007484:Iowa; D009584:Nitrogen; D006109:Poaceae / Q000378:metabolism*; D012987:Soil / Q000032:analysis*; D013997:Time Factors
D012987:Soil; D002244:Carbon; D009584:Nitrogen