Abstract. Recent climate changes have increased fire-prone weather conditions in many
regions and have likely affected fire occurrence, which might impact ecosystem
functioning, biogeochemical cycles, and society. Prediction of how fire
impacts may change in the future is difficult because of the complexity of
the controls on fire occurrence and burned area. Here we aim to assess how
process-based fire-enabled dynamic global vegetation models (DGVMs) represent
relationships between controlling factors and burned area. We developed a
pattern-oriented model evaluation approach using the random forest (RF)
algorithm to identify emergent relationships between climate, vegetation, and
socio-economic predictor variables and burned area. We applied this approach
to monthly burned area time series for the period from 2005 to 2011 from satellite
observations and from DGVMs from the “Fire Modeling Intercomparison
Project” (FireMIP) that were run using a common protocol and forcing data sets. The
satellite-derived relationships indicate strong sensitivity to climate
variables (e.g. maximum temperature, number of wet days), vegetation
properties (e.g. vegetation type, previous-season plant productivity and leaf
area, woody litter), and to socio-economic variables (e.g. human population
density). DGVMs broadly reproduce the relationships with climate variables
and, for some models, with population density. Interestingly, satellite-derived responses
show a strong increase in burned area with an increase in previous-season leaf area index
and plant productivity in most fire-prone ecosystems, which was largely
underestimated by most DGVMs. Hence, our pattern-oriented model evaluation
approach allowed us to diagnose that vegetation effects on fire are a main
deficiency regarding fire-enabled dynamic global vegetation models' ability to accurately
simulate the role of fire under global environmental change.