The Impact of Riparian Zone Degradation on Salmon Habitat: A Literature Review

Salmon populations in the United States are challenging, in large part due to widespread degradation of riparian zones that areas critical to maintaining healthy salmon habitats. Riparian zone influenced stream temperature, nutrient dynamics, and habitat complexity, all of which are essential to salmon reproduction, feeding, and shelter. However, currently, up to 90% of riparian zones in the western U.S. have been degraded by land use change and climate pressures. While many studies have examined riparian zone effects on salmon, findings are fragmented across disciplines, regions, and study scales. This literature review synthesizes existing researches. 16 peer-reviewed articles from Scopus dataset were systematically reviewed. Author identified key environmental factors affecting salmon habitat functions and link them to riparian features, including canopy cover, root systems, leaf litter, forest type, and large woody debris. Results show that riparian alters stream conditions critical to salmon life-cycles.