Macroinvertebrate response to wildfire in a wild and scenic river

Long, Kayla (2023) Macroinvertebrate response to wildfire in a wild and scenic river. Masters thesis, Northern Arizona University.

Text Long_2023_macroinvertebrate_response_wildfire_wild_scenic_river.pdf - Published Version Download (3MB)

Abstract

Wildfires, intensified by anthropogenic influences, impose substantial impacts on freshwater ecosystems. In the Southwest USA, wildfire season is succeeded by monsoon season, introducing indirect disturbances, such as erosion, sediment transport, channel modification, and turbidity, induced by post-fire runoff. Leveraging pre-existing data from 2005 and 2006, we assessed the short-term (< one year) responses of aquatic macroinvertebrates to wildfire and subsequent flooding, focusing on changes in density, diversity, and community composition. The investigation revealed substantial decreases in invertebrate density and taxa richness, with a dynamic recovery pattern, suggesting complex interactions between habitat stability, sedimentation, and the adaptability of invertebrate taxa. To disentangle these interactions, we categorized sites along Fossil Creek into predicted disturbance categories, considering factors such as initial sediment loading, potential future sediment loading, riparian burn severity, and anticipated changes in peak flows. However, the observed responses of dependent variables did not conform to predicted disturbance groups based on upland watershed conditions, nor the distinctions between upstream and downstream sites. We observed an unexpected but positive response, both at and downstream of a confluence, where flow events increased resource transfer, enhanced invertebrate drift, and scoured woody debris. This study provides valuable insight into the post-wildfire response of aquatic invertebrates over short time scales, particularly in systems characterized by travertine deposition.

Item Type:	Thesis (Masters)
Publisher’s Statement:	© Copyright is held by the author. Digital access to this material is made possible by the Cline Library, Northern Arizona University. Further transmission, reproduction or presentation of protected items is prohibited except with permission of the author.
Keywords:	Flooding; Aquatic invertebrates; Sediment; Southwest; Stream ecology; Wildfire; Arizona; Fossil Creek
Subjects:	Q Science > QL Zoology
NAU Depositing Author Academic Status:	Student
Department/Unit:	Graduate College > Theses and Dissertations College of the Environment, Forestry, and Natural Sciences > Biological Sciences
Date Deposited:	23 Jul 2026 23:38
Last Modified:	23 Jul 2026 23:38
URI:	https://openknowledge.nau.edu/id/eprint/6308

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