Have fire regimes and fire effects changed in Sonoran desert scrublands?
The Fire Effects Information System (FEIS) summarizes thousands of scientific publications to provide easily accessible information about how fire affects ecosystems and individual species. The ‘Fire Regime Synthesis’ about Sonoran desert scrub communities describes how fires are thought to have burned historically and how they burn today, and Species Reviews about associated native and nonnative species describe how these species respond to and affect fire.
Estimates of historical fire patterns in Sonoran desert scrub communities are based on observations of postfire responses of dominant plants, and the structure and fuel characteristics of contemporary, undisturbed communities. Because many of the dominant, long-lived woody and succulent plants in these communities are easily killed or injured by fire, and few are adapted to regenerate after fire, fires were thought to be historically very rare, small, and patchy. Today, however, fires appear to burn more often and severely and over larger areas because of increased human-caused ignitions, and increased fine fuel loads and continuity caused by nonnative invasive plant invasions. Sonoran desert scrub communities are not resilient to frequent, large, or severe wildfires, and native vegetation may not recover for centuries, if at all.
Recently published Species Reviews describe the biology and ecology of native species occurring in the Southwest, including saguaro, yellow paloverde, desert willow, Arizona sycamore, and Arizona walnut, and nonnative invasive species, including buffelgrass and Sahara mustard. Because many native Sonoran plant species are poorly adapted to fire, more frequent and severe fires are likely to harm their populations. For instance, the iconic saguaro is easily damaged and often killed by fire, and seedling establishment may be low after fire, especially when cover of mature saguaros and nurse plants is reduced. On the other hand, buffelgrass typically survives, resprouts, and often spreads after fire. Thus, fire is likely to promote buffelgrass and other invasive grasses while harming native plants.
The Fire Effects Information System provides thorough and accessible syntheses on over 1,000 plant and animal species and nearly 200 fire regimes across the United States. Land managers can use this information to help plan and adapt management actions on increasingly complex landscapes.