Ecological - Second Order
Fire and Landscape Mosaics
Invasive grass species can alter fire regimes, converting native terrestrial ecosystems into non-native, grass-dominated landscapes, creating a self-reinforcing cycle of increasing fire activity and flammable grass expansion. Analyses of this phenomenon tend to focus on the ecology and geography of the grass–fire cycle independent of human activities. Yet people introduce non-native grasses to new landscapes (eg via agriculture), facilitate their spread (eg via road networks), and are a primary source of ignition (eg via debris burning). We propose a new framework for this phenomenon that explicitly recognizes the important role of anthropogenic activities in the human–grass–fire cycle. We review links between land use and invasive species as well as ignitions, with a particular focus on the spatial and temporal co-occurrences of these activities to show that these two drivers of wildfires are inextricable. Finally, management strategies that could mitigate impacts are discussed.
In a nutshell:
The invasive grass–fire cycle, whereby non-native grasses promote fire leading to further invasion, is often framed as an ecological process that occurs in the absence of humans
Because people introduce invasive grasses and are a primary cause of fire ignition, invasive grasses and human ignitions likely co-occur, making these two wildfire drivers inextricable
We outline a new human–grass–fire cycle framework and suggest research directions that directly address the role people play in perpetuating invasive grass fires
We suggest a framework for management strategies that encourages fire and invasive species management communities to combine their knowledge and efforts to mitigate impacts