Invasive grasses can alter fire regimes, converting native ecosystems into grass dominated landscapes, and leading to the establishment of a grass-fire cycle. Our understanding of this phenomenon tends to focus on interactions between invasive grasses and invaded ecosystems rather than human involvement in the grass-fire cycle. However, it is becoming increasingly clear that human activities are integral to perpetuating the grass-fire cycle. People introduce fire-prone invasive grasses, facilitate their spread, and are the primary source of ignitions of grass fires. Therefore, we highlight the importance of these factors by emphasizing the link between invasive species and fire ignition with human land use, and explicitly link the spatial co-occurrence of invasive grass and human activity to show that these two drivers of wildland fire are inextricable.
Results/Conclusions
Our work proposes a new human-grass-fire cycle framework focused on the inclusion of anthropogenic influences in the grass-fire cycle. With outsized ecological impacts such as large scale ecosystem conversion, the human-grass-fire cycle is a cause for concern for conservation and land management agencies. Further, high economic costs are likely because invasive grass fires often burn near anthropogenic features where invasive species are established and fires ignition sources are prevalent. Therefore, we also propose management strategies based on the human-grass-fire cycle framework that can be used to mitigate impacts. These strategies encourage a holistic management approach that combines the expertise of invasive species managers, fire managers, and human dimensions research. We suggest that integrated management strategies can be used to combat invasion and altered fire regimes proactively before entering a human-grass-fire cycle, reactively when a human-grass-fire cycle is imminent, and adaptively once a grass-fire cycle is dominant. By pooling resources, both physical and knowledge based, we can most effectively mitigate the negative ecological and economic impacts from the human-grass-fire cycle.