And, although the same effect could be had by adding the rusted red iron mineral hematite, which is a poor conductor,
the resulting microbial growth was much smaller and slower (and nonexistent when nonconductive aluminum minerals were tried).
Global simulations conducted by the team found that
microbial responses to enhanced root activity under rising CO2, while depending on plant species, climate and soil mineralogy, led to a loss of global soil carbon stocks that counteracted the additional carbon storage
resulting from increased plant
growth in many regions of the world.