Sodergren, Clayton. 2023. Long-Term Effects of Fire Severity, Time Since Fire, and Topography on Douglas-Fir Canopy Complexity in the Western Cascades, Oregon, USA. Corvallis: Oregon State University. 36 p. M.F. Thesis.
The patterns of forest structure are inextricably linked to ecosystem function. Forest canopy complexity, while nebulously defined as a concept, generally increases through time as forests develop and is associated with late successional and old growth Pacific Northwest forests. Fire and topography are thought to be drivers of canopy complexity, particularly in coastal Douglas-fir/western hemlock forests that experience non-stand-replacing fire. This study sought to understand how patterns of canopy complexity are associated with patterns of topography and the processes of fire and post-fire successional recovery. Building on previous research conducted near the H.J Andrews Experimental Forest and Long-Term Ecological Research site, I linked lidar data to field data to look for associations between canopy complexity, time since fire, fire severity, and potential relative radiation. My findings of no associations between these variables differed from much of the literature. Reasons for these results may include chosen metrics, stand dynamics, simplified models, and/or data constraints.