| Ants (Hymenoptera: Formicidae) in British Columbia are ubiquitous and abundant in most biogeoclimatic zones of the province, have a demonstrated role in ecological processes and are an important food source for many vertebrates such as birds and bears. The objective of my dissertation was to undertake the first broad examination of an ant community in BC, assess responses of the community to seral forest development and determine what habitat elements are associated with ant presence or absence. Ants are a challenging fauna to study, however, as their social structure and foraging strategies complicate sampling. I characterize the sampling issues associated with ants and develop a protocol to optimize field collection. Guided by this protocol, I examined the ant community of the sub-boreal forests of west-central BC. I show that the structure of the ant community is strongly influenced by seral age which I suggest is indicative of temperature sensitivity in this fauna. The ant community increased in abundance and diversity, following the Individualistic Hypothesis of succession, until at least 13-15 yr post-harvest. The community then began to decline as canopy cover increased. Non-harvested stands, with mean summer litter temperatures of <10°C, were found to be largely devoid of ants. Most ant species were also shown to utilize woody debris for nesting, which is shown to have a significantly higher mean temperature as compared to soil, and may be a thermal refugia for ants. Ants selected specific decay classes and usually larger pieces of woody debris for nesting, as shown by logistic regression. It was also evident that ants were more likely to be found within 50-m2 sampling units when members of the same species were also found there, likely indicative of secondary site colonization via budding from polygynous colonies. Artificial shading of wood used for nesting resulted in a reduction in utilization by ants supporting the hypothesis that insolative heating of woody debris is critical for ants. Overall the ant fauna was shaped by factors related to temperature and the dependence upon woody debris is indicative of the thermal advantages of this resource. |
