Using a BACI design to assess stream ecology and chemistry response after wildfire

Freshwater Science
By: , and 

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Abstract

Wildfires can have complex effects on aquatic communities, which can be either beneficial or adverse depending on the setting. In California, USA, the size, frequency, and severity of wildfires has greatly increased over the last few decades. Understanding the effects of fire on aquatic ecosystem health and human land use has become increasingly important in managing the interface of the natural and urban landscape. In this study, we used a before–after control–impact (BACI) study design to test for differences in bed sediment chemistry, water chemistry, benthic algal biomass, and benthic macroinvertebrate communities between burned and unburned (control) watersheds, pre- and post-fire, using data collected before and after California’s 2017 Atlas, Nuns, and Tubbs wildfires. We found a treatment effect (burned vs control) on water chemistry, sediment trace-metal concentrations, algae, and community structure of benthic macroinvertebrates, but we found no evidence of an interaction between time period (pre- vs post-fire) and treatment. Both the difference in environmental factors between our control and burned sample sites and the proximity and degree of wildfire burn severity may have contributed to the results of this BACI study. Our results also highlight the importance of including control sites when assessing the effects of discrete disturbances, such as wildfire, to avoid spurious conclusions of disturbance effects that may be attributable to innate ecological variability.

Suggested Citation

Wulff, M.L., May, J.T., Huntsman, B., Waite, I.R., and Brown, L.M., 2026, Using a BACI design to assess stream ecology and chemistry response after wildfire: Freshwater Science, v. 45, no. 1, p. 1-17, https://doi.org/10.1086/738617.

Publication type Article
Publication Subtype Journal Article
Title Using a BACI design to assess stream ecology and chemistry response after wildfire
Series title Freshwater Science
DOI 10.1086/738617
Volume 45
Issue 1
Publication Date December 23, 2025
Year Published 2026
Language English
Publisher University of Chicago Press Journals
Contributing office(s) California Water Science Center
Description 17 p.
First page 1
Last page 17
Additional publication details