Data from: Aggregation but not organo-metal complexes contributed to C storage in tidal freshwater wetland soils

One of the many goals of wetland restoration is to promote the long-term
storage of carbon (C) in the terrestrial biosphere. Unfortunately, soil C
reservoirs in restored wetlands are slow to accumulate even after
hydrology and plant communities are reestablished. Oftentimes wetland
restoration changes the soil matrix and thus can dramatically alter how
soil C is stored and processed. Our research investigated whether soil
organic matter (SOM) preservation theories derived from studies in
non-wetland soil systems can be extended to wetland soils. We examined C
associated with water-stable soil aggregates, minerals, and metal oxides
within habitats of one natural and one restored tidal freshwater wetland.
This study revealed that a majority of the soil C in the natural site was
associated with large macroaggregates (> 2000 μm), and soils from
the restored site stored more C in small macroaggregates (> 250 to
< 2000 μm). Despite these different associations, the chemical
composition of SOM followed similar patterns across each aggregate-size
class. Results from the sequential extraction procedure suggest
organo-metal oxide complexes do not contribute to C stabilization in these
habitats. This research is one of the few studies that have examined C
stabilization related to soil structure in wetland soils. Our results
suggest soil aggregate formation may be an important mechanism driving C
stabilization, and that disruption to macroaggregates may limit C
accumulation in restored wetlands. Additional empirical research and
long-term field monitoring are needed to confirm linkages between
aggregate-C stabilization and accumulation in wetland soils.