Theory 09/The rival is a different mechanism/Soil carbon
Roots or Productivity?
The claim
Soil carbon tracks root biomass because root carbon enters mineral soil directly.
01The rival explanation
Root biomass is simply a proxy for productivity, and productive sites hold more carbon for that reason.
02What would tell them apart
Root exclusion holds productivity constant while removing root input.
03Prediction
Excluding roots should reduce soil carbon at equal litter input.
04Refutation
If carbon is unaffected once litter is held constant, the rival wins.