What is the main factor that differentiates aerial fuels from other types?

The primary factor that distinguishes aerial fuels from other types is their proximity to the ground. Aerial fuels refer to combustible materials such as leaves, branches, and other organic material that are located above the surface, typically in the canopy of trees or other elevated areas. This elevates their position relative to ground fuels, which are found close to the soil. The location of aerial fuels significantly influences how fire behaves, as it affects the convection and spread of heat. Elevated fuels can be more challenging to manage during firefighting operations because they often require aerial access for effective suppression.

While factors like the type of material, moisture content, and size and density are important in the overall context of fire behavior and fuel management, they do not fundamentally define aerial fuels as specifically as their position above ground does. This characteristic affects fire dynamics, including how quickly a fire can spread through these materials compared to those that are closer to the ground.