Understanding wildfire, vegetation shifts, and urban expansion in California landscapes

Wildfires are increasingly shaping land cover dynamics across California, where climate change, vegetation shifts, and expanding urban development are intensifying fire activity and altering ecosystem structure. Despite extensive wildfire research, the long-term land cover change and burn severity patterns across different ecosystem types remains insufficiently quantified at the statewide scale. This study investigates the interaction between land cover change and wildfire impact across California from 2000 to 2020 by integrating land cover and burn severity data. Net gains and losses among land cover classes were quantified to identify dominant landscape changes, while burn severity categories were intersected with land cover layers to calculate annual burn exposure for each layer. Linear regression was applied to detect temporal trends in wildfire exposure across land cover classes. Results reveal a clear expansion of developed areas accompanied by a contraction of forested landscapes over the study period. Trend analysis indicates increasing wildfire exposure in Evergreen Forests and Shrublands, while Grasslands and Wetlands show declining burn exposure. Evergreen Forests experienced the highest proportion of High Severity fires, whereas Shrublands were dominated by more frequent low-intensity surface burns. Regression modeling further confirms strong fire related association in forested ecosystems and comparatively limited wildfire interaction within urban and aquatic land classes. These findings demonstrate how wildfire activity, urban expansion, and vegetation transitions are jointly reshaping California’s landscapes. Understanding these ecosystem-specific fire response is essential for developing adaptive land management strategies, improving wildfire mitigation planning, and enhancing landscape resilience under intensifying climate pressures.