Danique Boissonneault | ALES Graduate Seminar

Event details:  A graduate exam seminar is a presentation of the student’s final research project for their degree.

This is an ALES MSc Final Exam Seminar by Danique Boissonneault.  This seminar is open to the general public to attend.

Zoom link: https://ualberta-ca.zoom.us/j/94557409272

Thesis Topic:  Influence of edge effects on forest structure adjacent to oil sands disturbances in boreal forests

Seminar Abstract:

Industrial development in Alberta’s oil sands region has created a dense network of anthropogenic forest edges, altering forest structure, composition, and microclimates. This thesis examines how edge effects influence forest structure in mature upland boreal forests associated with adjacent in situ oil sands footprints. Field data were collected from 46 edge sites in the Athabasca oil sands region during the 2023 and 2024 growing seasons. I compared narrow linear disturbances (seismic lines) and larger polygonal clearings (abandoned wellpads) to assess tree mortality, recruitment, stem density (Chapter 2), and the availability of coarse woody debris (CWD) and snags (Chapter 3). Edge effects were more pronounced next to larger gaps, but varied substantially by edge orientation. West-facing edges, exposed to prevailing winds, were associated with higher probabilities of large-tree mortality and snag formation. Tree recruitment declined with distance from the edge but was higher along west-facing edges than south-facing ones. Stem densities peaked within 20 m of edges, illustrating an edge-sealing effect. Recently fallen CWD was sparse near edges, while older CWD and snags were shaped by edge distance and edge exposure. Overall, this study demonstrates that edge orientation, gap size of adjacent footprints, and time since disturbance interact to shape forest dynamics and CWD availability along anthropogenically-derived forest edges within Alberta’s oil sands region. These findings highlight the nuanced impacts of oil sands development on forest structure for increasingly dissected forests and underline the importance of considering edge design into reclamation planning to maintain biodiversity and support species that rely on CWD and snags, such as saproxylic species and cavity-nesting birds like the pileated woodpecker (Dryocopus pileatus).