Submitted to: ASA-CSSA-SSSA Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: November 7, 2003
Publication Date: November 7, 2003
Citation: CAMBARDELLA, C.A., ISENHART, T.M., SCHILLING, K.E., DROBNEY, P., SCHULTZ, R.C. SOIL CARBON POOLS IN A TALLGRASS PRAIRIE RECONSTRUCTION CHRONOSEQUENCE. ASA-CSSA-SSSA PROCEEDINGS. 2003. CD-ROM. MADISON, WI.
Conversion of disturbed land to native grasslands can increase soil organic C (SOC) and enhance C sequestration to mitigate increases in atmospheric CO<SUB>2</SUB>. Our hypothesis was that SOC would increase with time since prairie reconstruction. Experiments were conducted at Neal Smith National Wildlife Refuge near Prairie City, IA, where blocks of land have been returned to native prairie every year since 1993. We used a stratified sampling design to identify sampling locations within six reconstructed areas, three native remnant areas, and two cultivated areas blocked by three upland soil types. Soil cores were collected in May 2000 to a depth of 120 cm. SOC ranged from 77.9-105.5 and 4.49-12.1 Mg C ha<SUP>-1</SUP> to a depth of 120 and 15 cm, respectively. We did not observe a consistent positive change in soil C at any depth with time since reconstruction. We did identify two potential short-term indicators of longer-term changes in SOC. We found a positive correlation for the difference in C content of the two surface horizons and time since prairie re-establishment, which suggests that C is preferentially accumulating in the 0-15 cm depth increment. We also found that accumulation of C in the heavy sub-fraction of POM may serve as an early indicator of the potential of the system to sequester stabilized SOC. Future work at the refuge will focus on optimizing our ability to detect changes in ecosystem parameters.