Year of Award
2025
Document Type
Thesis
Degree Type
Master of Science (MS)
Degree Name
Wildlife Biology
Department or School/College
Wildlife Biology Program
Committee Chair
Joshua Millspaugh
Committee Co-chair
Hannah Specht
Commitee Members
Winsor Lowe, Walter Wehtje
Keywords
bird, aspen, fire, montane, community, occupancy
Subject Categories
Terrestrial and Aquatic Ecology
Abstract
Fire is a major ecological force in most terrestrial systems, but the responses of animal communities to fire vary markedly across ecosystems due to variability in fire regimes and vegetation communities. Quaking aspen (Populus tremuloides) is unique within coniferous forests of western North America for its ability to regenerate following wildfire via vegetative resprouting. As managers employ techniques to restore fire regimes and conserve declining aspen forests, it becomes important to understand how aspen alters postfire communities. Our objectives were to (1) assess how aspen interacted with fire severity and years since fire to influence avian species and community responses to wildfire and (2) evaluate potential habitat mechanisms explaining these relationships. We conducted avian point counts from 2019 to 2024 at 84 sites in mixed conifer-aspen forests in western Wyoming that burned during the 2018 Roosevelt Fire. We employed a two-step, multi-species occupancy modelling framework to account for imperfect detection of 66 species and estimate effects of covariates on occupancy, richness, and dissimilarity. We found that aspen presence prior to fire had a positive impact on post-fire species occupancy, total richness, and richness across most guilds, dampened the positive effect of time on species richness, and reduced change in species composition over time. Habitat relationships suggested that increased understory habitat in areas with more pre-fire aspen cover had a positive relationship for most guilds, particularly for shrub and ground nesting species. Observed species and guild responses generally matched our hypotheses, but varying life history strategies of species within guilds may have led to unexpected guild responses. Our results highlight the biodiversity benefits of aspen stands in burned landscapes by harboring more developed early seral, understory habitat sooner after fire than surrounding conifer forests. Management actions directed at maintaining landscape heterogeneity and biodiversity in fire prone landscapes should consider the value of aspen stands for these efforts.
Recommended Citation
Lane, Cody Q., "Aspen stands enrich bird communities following a wildfire in a montane, mixed conifer forest" (2025). Graduate Student Theses, Dissertations, & Professional Papers. 12458.
https://scholarworks.umt.edu/etd/12458
© Copyright 2025 Cody Q. Lane