File uploads: We have fixed an issue which caused file uploads to fail. We apologise for the inconvenience it may have caused.

Published May 11, 2023 | Version v1
Dataset Open

The contribution of Fe(III) reduction to soil carbon mineralization in montane meadows depends on soil chemistry, not parent material or microbial community

  • 1. University of Nevada Reno
  • 2. University of Minnesota
  • 3. Colorado School of Mines

Description

The long-term stability of soil carbon (C) is strongly influenced by organo-mineral interactions. Iron (Fe)-oxides can both inhibit microbial decomposition by providing physicochemical protection for organic molecules and enhance rates of C mineralization by serving as a terminal electron acceptor, depending on redox conditions. Restoration of floodplain hydrology in montane meadows has been proposed as a method of sequestering C for climate change mitigation. However, dissimilatory microbial reduction of Fe(III) could lead to C losses under increased reducing conditions. In this study, we explored variations in Fe-C interactions over a range of redox conditions and in soils derived from two distinct parent materials to elucidate biochemical and microbial controls on soil C cycling in Sierra Nevada montane meadows. Differences in parent material were associated with different rates of Fe(III) reduction at increasing soil moisture levels, but not with differences in soil C mineralization. Known Fe(III)-reducing taxa were present in all samples but neither the relative abundance nor richness of Fe(III) reducers corresponded with measured rates of Fe(III) reduction. Under reducing conditions, our results suggest that Fe(III) reduction contributes to C mineralization only when Fe-bound C is present. However, Fe-bound C was not present in all of our soils and was below theoretical limits for C sorption onto Fe-oxides where it was found. Overall, our results suggest that meadow-specific soil chemistry drives Fe-C interactions and that the impact of Fe on C cycling in montane meadows may be smaller than in other ecosystems.

Notes

Funding provided by: California Department of Fish and Wildlife
Crossref Funder Registry ID: http://dx.doi.org/10.13039/100006238
Award Number: P1496002 00

Files

README.md

Files (891.4 kB)

Name Size Download all
md5:266c698e9ba573188ba8feff30767d35
840.3 kB Download
md5:42b1edf5c04d57b90f11e53002d17f7b
17.6 kB Download
md5:6a53f158268310ccaf4352b6cc8aa81a
17.5 kB Download
md5:60afb505244800b94fc016e9ba11cae7
12.8 kB Download
md5:25ab53f2a7c5d242d94f9aecaff0306a
3.2 kB Preview Download