Heather Clarke

Determining the effects of partial harvesting in riparian buffers on cavity-nesting birds in the boreal forest.

email: hclarke@ualberta.ca

MSc Research
My research is focused on determining the effect of riparian harvesting on cavity nesting birds. Towards the end of my undergraduate degree I became increasingly interested in the effect of anthropogenic disturbances on natural systems. An opportunity to work in this area, studying cavity-nesting bird communities, was presented to me by Susan Hannon and I began working on my MSc in her lab in the winter of 2005.

My study site is located in central Saskatchewan, in the boreal-plains ecoregion. This area represents the transition zone from the less vegetated, more arable land in the south, to the boreal forest in the north. It provides habitat for a diverse array of wildlife due to its structural and compositional diversity, and is of increasing conservation concern as harvesting practices increase throughout the region.

Weyerhaeuser is attempting to alleviate some of this harvesting pressure by developing alternative logging practices, intended to emulate natural disturbances. In riparian areas, the practice is applied through the development of a 40 meter wide, partially harvested (5-25% tree retention) buffer along lake edges. This practice has been developed very recently, and has not yet been evaluated in terms of ecosystem effects. This is where my research comes in….

I am examining the community structure and of cavity-nesting birds in naturally burned, partially harvested, and intact riparian forests. This will determine both the effectiveness of a partial harvest approach in terms of natural disturbance emulation, as well as any overall harvesting effects on the bird communities.

In addition, I am examining nesting and foraging habitat selection by cavity nesters at tree, stand, and larger landscape scales. This will determine which features, if any, are of particular interest for forest companies in future harvest planning, and conservationists for the development of protected areas.