Which type of fuel includes large brush, heavy timber, stumps, branches, and dead timber on the ground?

The correct answer is heavy fuel. Heavy fuel refers to materials that are denser and more substantial in size, such as large brush, heavy timber, stumps, branches, and dead timber found on the ground. These types of fuels require more energy to ignite and typically burn for a longer duration once ignited due to their mass and moisture content.

In fire behavior, heavy fuels are particularly significant because they can contribute to intense burning conditions. Fires fueled by heavy materials can produce high heat output and create greater challenges for suppression efforts. Understanding the characteristics of heavy fuels helps firefighters predict fire behavior, assess risks during a wildfire, and develop effective firefighting strategies.

Other types of fuel, such as light fuels (which include grasses and small shrubs), burn quickly and with less intensity. The terms Atypical, Moderate, and Median do not specifically categorize fuels based on size or density in the context of fire behavior, making heavy fuel the most accurate descriptor for the materials listed in the question.