Are microbial bodies the stable carbon we seek in tropical forests?

Physiochemical characteristics of organic matter (OM) that promote long-term storage in soils must be understood to predict feedbacks to climate change. Strongly weathered tropical soils are of particular interest because of their large reserves of carbon. The chemical character of OM alone does not confer preferential retention in soils. Rather, physical protection of organic matter from decomposers is necessary, (e.g. organo-mineral association or aggregate-occlusion). Still, the biomolecules that promote physical protection are likely to vary across biomes. Tropical rainforest studies suggest that waxes and microbial proteins promote stable organo-mineral associations in strongly weathered clays, which could inform carbon storage efforts.