Phytomass is the mass of plants, including dead attached parts, per unit area at a given time. Phytomass is commonly measured in units of kilograms per hectare (or pounds per acre). It is a direct measure of biomass production, carbon storage, energy availability, and available forage for potential grazers and users of rangelands. It also serves as a fuel source for rangeland fire. Phytomass is not to be confused with the next indicator, primary productivity, which describes rates of biomass accumulation. Spatially explicit maps of biomass and standing dead material are becoming extremely useful for providing inputs into wildfire behavior models.