|DOLD, CHRISTIAN - Orise Fellow|
|Sauer, Thomas - Tom|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/15/2018
Publication Date: 1/9/2019
Citation: Dold, C., Cambardella, C.A., Hatfield, J.L., Prueger, J.H., Sauer, T.J. 2019. Carbon sequestration in a reconstructed prairie site in Central Iowa [abstract]. In: Preceedings of the 2018-2019 International Soils Meeting, January 6-9, 2019, San Diego, CA.
Technical Abstract: Reconstructing former cropland to tallgrass prairie can impact ecosystem carbon (C) storage. In this study, we evaluated C dynamics for a 7.6 ha reconstructed prairie site at Neal Smith National Wildlife Refuge in south-central Iowa. We collected soil cores (0-15, 15-30, 30-60, 60-90 cm, n = 107) and surface samples (0-7.5, 7.5-15 cm) from 2003 - 2013 from sampling locations along 18 transects to analyze soil organic carbon (SOC), and quantified eddy covariance-derived Net Ecosystem Production (NEP) from 2003 – 2017. A total NEP of 17.3 Mg C ha-1 was taken up by the reconstructed prairie, corresponding to +1.33 ± 0.26 Mg C ha-1 yr-1 from 2005 – 2017. The annual NEP increased from 2006 – 2009 and thereafter gradually decreased until 2015. Soil SOC concentration increased from 2.59 ± 0.04% to 2.75 ± 0.05% from 2003-2013 in surface soils (0-7.5 cm). Mass-based surface SOC content (0-15 cm) significantly increased by +2.39 ± 0.40 Mg ha-1 in this 10-year period (+0.24 Mg ha-1 yr-1). The rate of SOC change decreased to 1.45, 0.42, 0.16 and -0.51 Mg ha-1 yr-1 between 2004, 2008, 2011 and 2013, respectively. At deeper depths (0-90 cm), SOC increased from 1.30 ± 0.33% to 1.35 ± 0.31%, while bulk density decreased with a range of -0.22 to -0.29 g cm-3 from 2003 - 2013. While no significant SOC changes were observed at 0-90 cm from 2003 - 2009, the mass-based SOC content significantly decreased by -11.2 Mg ha-1 from 2003-2013. All methods indicate that C content initially increased and then decreased in the reconstructed prairie ecosystem. The magnitude of C change was greater for the NEP method, which comprises soil and plant C, suggesting a substantial amount of C was stored in plant material and litter.