Fig. 4. Mean densities of potential cavity-trees with regard to stand type in unharvested stands, remnant stands, and clearcuts of balsam fir (Abies balsamea) and black spruce (Picea mariana) in the Chauvin and Martin-Valin controlled wildlife harvesting zones, Quebec, Canada. This figure shows that the availability of potential cavity-trees is significantly reduced in managed stands. Different letters indicate a significant difference between treatments at P = 0.05 using the Tukey’ hsd test. The five treatments were compared simultaneously.