Lability of Organo-Mineral Complexes in Dynamic Soil Biogeochemical Systems.

The fact that minerals are dynamic entities in soils is apparent from the fact that their structures change measurably on the time scale of days, and in response to dynamic changes in biological activity.  Soil organic carbon sequestration is one of the many important effects of this mineral transformation.  This is reflected in the fact that degradation and stabilization of SOM in soil pores and at soil particle surfaces is coupled tightly to mineral transformations that occur locally, particularly when soils are enriched in kinetically unstable mineral phases.  This is one mechanism whereby organic matter may be postulated to partly control its own sequestration.  Results from age and climate gradients of Hawaiian soils suggest that organic carbon accretion is favored in soils where incongruent mineral weathering rates compare with the time scale of DOC influx, sorptive reactions, and humification.  Solid phase organic C stabilization results when weathering and transport provide sufficient nano-particulate metals for organic complexation and aggregate formation.