New paper by Peng et al 2019 dealing with effects of biochar addition on the fluxes and C turnover in boreal forests soils.

The results of the study indicate that wood-derived biochar produced at high pyrolysis temperatures had no significant effects on soil heterotrophic respiration obtained from lab incubations in boreal Scots pine forests at 5 to 10 Mg ha–1 application rates. Biochar addition increased soil total organic C, C/N ratio, and moisture content, but had no clear effect on soil total N, nor on the temperature sensitivity of soil respiration. The turnover time of soil C was unaffected by biochar addition. These results indicate that from a C sequestration point of view, biochar addition did not accelerate the mineralization of soil organic C, and could lead to higher stable C stocks in the surface soil layer.