The level of T. atroviride SC1 present in the four different treatments immediately after inoculation (0 weeks) was
2.1e4.5 105 CFU g1 dry substrate and increased rapidly to 106e107 CFU g1 after 2 weeks of incubation. Sixteen weeks after inoculation, the CFU values measured in the bark mixture and the larch and pine bark were still high: 1.9 ± 0.9 107, 3.1 ± 1.2 106 and 2.5 ± 0.5 106 CFU g1 dry substrate, respectively. Only in the fir bark was the level of T. atroviride SC1 lower at the end of the experiment than at the time of inoculation, having decreased from 2.7 ± 1.8 105 to 4.8 ± 2.7 104 CFU g1 dry bark. Each treatment reached its maximum CFU value at a different time, but at the fourth week, CFU values were high in all of the inoculated treatments, ranging from 7.5 106 in pine to 1.96 107 in larch bark. No Trichoderma spp. CFU were ever isolated from the untreated control.