Riparian zones occur along the edges of water bodies such as rivers, springs, lakes, and marshes. Native riparian vegetation provides critical benefits to riparian zones such as stabilizing streambanks, controlling erosion, providing habitat for wildlife, and regulating water temperature and are generally better adapted to fire due to higher content of moisture. However, anthropogenic disturbances such as water management, urbanization, and the introduction of invasive and non-native plants threaten native riparian vegetation communities. Otay Valley Regional Park (OVRP), one of the largest open spaces within southern San Diego County, experienced 18 brush fires (1.5 acres of damage) ignited by people experiencing homelessness in September 2019. These fires occurred near the Otay River, which has both native and non-native vegetation. The overarching objective of this study is to understand the impact native and non-native invasive vegetation has on fire and burn severity patterns in OVRP. Vegetation types are defined by the dominant plant species in the area or by the growing patterns of the plants (freshwater marsh, riparian scrub, etc.). Satellite image metrics, normalized difference vegetation index (NDVI) and difference normalized burn severity (dNBR) will be approximated for each mapped vegetation type in OVRP. The results of this presentation will inform future field work in OVRP to confirm the impact of specific native and non-native riparian plant species that are at risk to fire or challenges for management.
