Science Center Objects

Fire has had a very different influence on the forests and shrublands of California. Unlike the case in many forests where fires have been excluded for over a century, shrublands throughout the state have experienced the opposite impact. Invasive grasses that burn more readily than native plants have increased the frequency of wildfires in southern California shrublands. As fire clears swathes of native shrubs, these invasive plants often fill in the space left behind, continuing the cycle. Dr. Jon Keeley works with the U.S. Navy and other state and federal partners to learn about the intricate components of natural wildfire patterns and the consequences of plant invasions into natural ecosystems.


Across the Western U.S., a history of fire management has altered wildfire patterns on public lands. As a result, more frequent or severe blazes have destroyed native vegetation and cleared a path for invasive plants, like the yellow cheatgrass pictured above, across many ecosystems. These non-native plants can reduce food sources or habitat for wildlife, and can even worsen these harmful wildfire cycles and their effects on human communities. WERC’s Dr. Jon Keeley collaborates with the U.S. Navy and other groups to understand how fire and non-native plants interact across different landscapes, including islands, forests, and shrublands.


Prescribed Fire on San Clemente Island:

San Clemente is a U.S. Navy-owned island located off the coast of southern California. As non-native grasses have spread across San Clemente, the Navy has asked Dr. Keeley and team to determine the success of using prescribed, controlled fires to clear invasive grasslands and promote the number of native grasses. The results from this study will help land and resource managers with the Navy and other agencies identify efficient methods for protecting and restoring native habitats and endangered plants and animals on San Clemente Island.


Human Activity and Invasive Species

Using historical aerial photographs, Dr. Keeley is leading a study on the role of humans in changing natural wildfire patterns and introducing invasive plants to western ecosystems. The photographs offer insight into changes in native and invasive vegetation across southern California over time. Dr. Keeley’s project also examines how current land use patterns are affecting the spread of invasive plants in high-elevation environments.