Figure 5: Adaptation of the intermediate productivity-fire activity hypothesis as drawn from Ellis et al. (2022) using a) the total underlying represented area (M km2) of the Earth’s surface, b) the mean underlying ecoregion flammability threshold (EFT) and c) the mean underlying inflection point slope estimate (i.e., 1 / ϕ3). Solid vertical lines in all figures highlight the 25th, 50th, and 75th percentiles of global net primary productivity (NPP) for all ecoregions with identified EFTs, roughly illustrating the range of intermediate productivity most associated with fire activity (~1.2 – 5.4 t C ha-1year-1); points in c) represent the mean location for biome-level NPP and fire activity indices, highlight that most ecoregions are, if not within the intermediate productivity range, near it.