Ground-nest densities and nesting habits of 13 ant species were quantified in five postfire age classes (1, 9, 23, 47, and 79 yr old) in the lichenâspruce woodland of Quebec, Canada. There were no significant differences in ant nest densities between age-classes (average of 163 nests/ha), but there were significant differences in ant community structure. Ant communities were dominated by Formica podzolica, F. aserva, F. hewetti, and Myrmica detritinodis, which accounted for 77% of occupied nests. Some species (e.g., F. podzolica) were specialists in their nesting habits, whereas others (e.g., F. aserva) were generalists and built their nest in a variety of substrates. Nest densities of F. aserva correlated with several habitat factors, but these correlations could have been spurious because they were not related to this speciesâ nesting habits. However, significant positive correlations found between Camponotus herculeanus and Leptothorax canadensis and coarse woody debris (CWD) may be biologically significant, because these two species nested exclusively within CWD. Nest densities of M. detritinodis and M. fracticornis were relatively high in the youngest and the oldest age classes, resulting in a negative correlation with CWD. We suggest that the distribution of these two species is caused by their preference for older forests to a high rate of fire survival and possibly to competitive release in the year after disturbance. According to canonical correspondence analysis, at least 75% of the variation in ant species cannot be explained by the habitat factors measured. Future research should include, therefore, experimental manipulations to determine the extent to which other factors, such as interspecific interactions, may structure ant communities in lichenâspruce woodland.