INTRODUCTION
In north central BC, the current mountain pine beetle outbreak, and the management response to it, is changing the forest environment. In the public media rhetoric such as ‘devastation’ and ‘environmental disaster’ have been common descriptors of the consequences of the beetle; with a desire to ‘repair’ the damage through logging and replanting. But what are the actual impacts, how rapidly will recovery occur, and how can we reduce economic losses while maintaining ecological values? There are many efforts underway to address those questions. In this note I report on progress looking at our two tree squirrels: the northern flying squirrel (Glaucomys sabrinus) and the red squirrel (Tamiasciuris hudsonicus).
Both of these species are common in our forests, and play many ecological roles. They are prey for many carnivores with the red squirrel, for example, being a staple of the northern goshawk and other daytime predators. The flying squirrel, a nocturnal animal, is prey to nighttime predators such as owls. In turn, both squirrel species can be significant predators on nesting birds. The red squirrel consumes conifer seed, spreads seed through caching behaviour, and uses trees for nesting and escape. The flying squirrel depends on trees for its main mode of locomotion (gliding) as well as for nesting, and for tree lichens as a food source. Both species consume fungi, including above ground (‘mushrooms’) and below ground (‘truffles’) most of which are ectomycorrhizal species (associated with tree roots) important for tree growth. The flying
squirrel is famous for its use of truffles, and has been shown to be an effective dispersal agent for fungal spores.
One could expect all these resources important to the squirrels (i.e. habitat quality) to be severely diminished by logging and perhaps also with tree mortality from the beetle.
In this study, we used live–trapping to examine the effect of time since major disturbance (natural and logging), and the pattern of disturbance (fragmentation), on squirrel presence and abundance. This was designed as an extensive sampling program to test predictions from models built using more intensive, localized field study (e.g. Cotton and Parker 2000). Results from this study and other field projects will support another BV Centre project, which is using modeling to simulate potential ecological consequences, through time, of the interaction of natural disturbance and logging.
The study area is the Nadina Forest District of the Northern Interior Forest Region (BC Ministry of Forests and Range), and includes the Lakes Timber Supply Area (TSA) and the Morice TSA. Forests of the Lakes TSA are dominated by lodgepole pine and are at the heart of the beetle outbreak. The Morice TSA is on the leading edge of the outbreak (Eng et al. 2005) and has more diverse terrain and tree species composition.
