Marc-Antoine Leclerc, MSc
The effects of single-objective management on disturbances in central interior dry forests of British Columbia
B.Sc., Forest Sciences, University of British Columbia (2014)
I like to know how things work and I am happiest when moving and when I am outside. I grew up watching loads of nature shows and spending the majority of my time outside, so I developed curiosity, and a sense of wonder for the great outdoors. Research in forestry was the natural next step because it allowed me to hike around in the bush and look at neat things! Specifically, I enjoy learning how parts of a system work individually, and then how those pieces work together and fit into the system as a whole. This lead to researching the concept of single objective management and how having a narrow focus may yield unintended results. My research looks into the effects of mule deer winter range management on disturbance likelihood.
Changes in disturbance likelihood resulting from single objective management
Mule deer are an important game species in the dry forests of central interior British Columbia. Mule deer require old Douglas-fir dominated forests with a multilayered structure, moderate to high canopy cover, and a clumpy tree distribution to survive through the winter. Past silvicultural practices have resulted in a reduction of such forests creating a need to balance habitat maintenance and timber extraction. I analyzed the short and long-term effects of mule deer winter range management on forest stand attributes and subsequent susceptibility to western spruce budworm, Douglas-fir beetle, and wildfire. I predicted that mule deer winter range management would result in lower susceptibility to western spruce budworm, Douglas-fir beetle and wildfire in the short term while susceptibility would be greater for all three disturbances in the long-term. Mule deer winter range management resulted in a reduction in sub-canopy tree density and basal area, canopy cover and leaf area index, while an increase in large woody surface fuels in the short-term. Over the long-term forest attributes of treated stands did not differ from untreated stands except that leaf area index and large woody surface fuels in treated stands were less than in untreated stands. Further, mean basal area increment in sub-canopy trees increased following the implementation of mule deer winter range management, suggesting with the other forest attributes, that stands were able to recover in the long term. The changes in forest attributes in treated stands did not alter the susceptibility to western spruce budworm, while treated stands were less susceptible in the short-term to Douglas-fir beetle. Likelihood of crown fire increased in the short-term, but was lower in the long-term likely due to changes in the amount of large woody surface fuel on the ground.
The prospect of widespread application of mule deer winter range management is of great interest to timber companies as such management would provide harvesting opportunities in areas that would otherwise be restricted. I therefore used GIS to forecast the possible effect of widespread mule deer winter range application on fire risk in dry forests. I predicted the widespread application would result in a more homogeneous landscape with a lower fire risk. Application of mule deer winter range management to all eligible stands did result in a more homogeneous and aggregated landscape that was dominated by the low fire risk class. This suggests that mule deer winter range management may create a more fire resistant landscape.
Application of such a management tactic should be used with caution because although mule deer winter range management may allow for timber extraction while enhancing habitat and potentially acting as a fuel treatment, the complex network of feedbacks in the dry forests may be altered leading to unintentional changes in the forest system. Therefore, my research highlights the potential trade-offs and synergies that may result from managing a forest solely for a single objective.