Abstract
An important feature of ecosystem-based forest management in the boreal mixedwood of northern Alberta is the emulation of natural disturbances such as wildfire. Post-fire landscapes typically include unburned or partially burned patches of forest (“remnants”). Remnants are thought to provide heterogenous structure, and support understory forest communities within a disturbed landscape. While forest managers leave remnant patches within harvest blocks to emulate the structural effects of fire, it is unknown if they are effective analogues. My objective was to examine if harvest and fire remnants are effective at maintaining understory vascular plant communities in a post-disturbance landscape, and to determine if they exhibit differences in structure and plant diversity. We further investigated if changes in remnant structure caused by tree mortality were associated with differences in understory microclimates and/or understory vegetation communities. We sampled in three harvested and three burned areas ~a decade after disturbance, and within each area sampled 3-7 island remnants. For each remnant, a “reference” (undisturbed continuous forest) was identified. At each island remnant and reference, the edge of the forest and the interior were sampled for collected microclimate, tree, and understory vegetation data that were analyzed using a taxonomic approach.
I found different communities to occur within fire and harvest sites. I did not detect any significant differences between the understory composition in islands or references or between edge and interior plots. I did find links between tree mortality and understory composition and cover but were unable to link it to different microclimates. I also found that plots with high canopy covers and tree basal areas were positively associated with shade tolerant later successional species.
I found different communities to occur within fire and harvest sites. I did not detect any significant differences between the understory composition in islands or references or between edge and interior plots. I did find links between tree mortality and understory composition and cover but were unable to link it to different microclimates. I also found that plots with high canopy covers and tree basal areas were positively associated with shade tolerant later successional species.
About the Author
Marcel Schneider earned a Bachelor of Science in Environmental and Conservation Sciences from the University of Alberta in 2019. After a brief stint in environmental consulting, he enrolled in the Masters of Science in Forest Biology and Management at the University of Alberta to pursue his passion for forests. In his free time, he enjoys hiking, climbing, skiing and crosswords.
|