Bamboos are widespread in the subtropics and tropics. They grow quickly, and are therefore important substitutefor timber. Bamboo forest management and cultivation often include removing competitive trees; thus theseshifts in forest composition should cascade to impact soil communities and the processes they mediate. Using along-term (12 year) bamboo forest management study, we determined the impact of bamboo forest managementon soil microbial and nematode community composition through time (2008–2010). Surprisingly, we found thatconversion from a mixed and relatively diverse bamboo forest to a pure bamboo forest did not affect bamboobiomass. However, the soil fungal:bacterial ratio, nematode diversity index, and fungivores:bacterivores alldeclined within and across years. Taken together, our results suggest that conversion from mixed to purebamboo forest can cause a switch from the fungal-based to the bacterial-based energy channel, i.e., acceleratethe energy flow and reduce the stability of the soil ecosystem. The findings suggest that managing for a mixedbamboo forest may increase forest diversity and health overtime.