The “Long-term ecological effects of forest fuel and restoration treatments” Special Feature focuses on the status of the national Fire and Fire Surrogates study (FFS) after twenty years of research. The FFS study was initially proposed in response to an important finding of the Sierra Nevada Ecosystem Project (SNEP, 1996) which stated, “Although silvicultural treatments can mimic the effects of fire on structural patterns of woody vegetation, virtually no data exist on the ability to mimic ecological functions of natural fire.” Thus, the FFS was designed as a multisite, multidisciplinary study to evaluate the long-term ecological consequences of prescribed fire and its mechanical surrogates. All treatments were intended to reduce the risk of high-intensity, severe fires while restoring resiliency in widespread seasonally dry forests originally characterized by frequent, low-moderate-intensity fire regimes. It is recognized that the structure and composition of such forests have been altered by fire suppression and exclusion, livestock grazing, invasive species, and preferential harvest of large-diameter trees (Arthur et al., 2021; Hagmann et al., 2021). These changes have created conditions of increased tree density and altered species composition with generally smaller tree sizes, and increased fuel loads in the western United States (US) that help to support increasingly larger and more severe fires as seen over the last few decades (Hagmann et al., 2021). It also appears that where such forests burn severely, they are tending to burn severely in subsequent fires inhibiting recovery to forest and potentially contributing to conversion to non-forest vegetation types (Coop et al., 2020). It is widely thought that forests with these elevated hazard conditions would benefit from some form of active management such as prescribed fire, mechanical treatments, or both. In contrast, fire exclusion in many eastern US oak ecosystems reduces flammability by facilitating the increased abundance of mesophytic species, thus limiting the capacity for restoration with prescribed fire (Alexander et al., 2021).