Fuel load is how much burnable material a patch of ground carries, expressed as oven-dry mass per unit area, typically kilograms per square metre or tonnes per hectare: grassland often carries under half a kilogram per square metre, a litter-covered forest floor a few kilograms, and heavy slash after logging far more. The number that matters for fire behaviour is not everything present but the available fuel, the fraction actually consumed in the passing flame front, because a thick log may char while the fine litter around it burns away entirely. The rule to carry is that energy released per unit area equals available load times the fuel's heat of combustion, which is why doubling the litter roughly doubles the energy a front releases as it passes. The confusion this resolves is between load and speed: a heavy fuel load makes an intense fire, not necessarily a fast one, since speed is decided by how easily fine fuel ignites. After this Concept you can estimate the energy per unit area available to a fire from a description of the ground it will cross.
Fuel loading is the mass of combustible vegetation per unit area or volume, used to predict potential wildland fire behavior; it is disaggregated into distinct measures — total, fine, available, cano…