Collaborative Research: FIRE-MODEL: Using multitemporal ecosystem energetics to understand changes to fuels and future fire regimes

Wildfire is a key process for many types of ecosystems. Over the past century, however, fire activity has changed dramatically. One important driver of this shift has been the accumulation of flammable materials, such as fallen leaves and dead wood, that provide fuel for wildfires. Despite its importance, fuel accumulation remains difficult to model because it involves processes unfolding on very different timescales: the slow buildup and decay of fuels and their rapid combustion during wildfire. This project investigates how fuel accumulation and fire activity are changing over time in a range of landscapes in western North America. This includes places where fire is limited by fuel availability as well as those where fire activity is driven more by flammability. The project uses these insights to improve models that predict future fire regimes and works closely with land managers to co-develop model improvements and scenarios that support decision-making. This project: (1) examines, quantifies, and reduces uncertainty in models of the slow but steady process of fuel accumulation, and (2) uses improved models to investigate how changes will influence rates of energy conversion at both slow and fast time scales and across watersheds. The project first investigates the process of decomposition, which reduces a critical source of uncertainty in projecting future fuel accumulation. The project also uses long-term empirical datasets of litter decomposition to perform uncertainty analysis and multi-objective assessment of several decomposition models. In parallel, the research team engages with management partners to co-produce model development and to design management-relevant scenarios. Then, the team uses those scenarios across several watersheds in western North America to project how combined scenarios of environmental variability and management alter wildfire regimes. Coproduction efforts align the team’s modeling efforts with management needs and provide managers access to critical technical infrastructure. The project engages the next generation of scientists in the theory and practice of fire ecology, biogeochemistry, ecohydrology, and fire regime modeling. The project also delivers a workshop to train modelers at the graduate student and early-career researcher level. This convergence research- spanning biology, geosciences, and mathematical and physical sciences- advances theories of ecosystem energetics in the context of natural and managed fire regimes. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.