Which of the following is categorized as heavy fuels?

Heavy fuels are characterized by their larger size, greater density, and the amount of energy they can release when burned. This category typically includes materials that take longer to ignite and produce more intense, prolonged heat and flames.

The option that includes slash, brush, heavy timber, and stumps represents these characteristics well. These materials are often found in forested areas or regions with significant vegetation, and their physical attributes make them capable of sustaining intense fires. Heavy timber, for instance, will burn more slowly than lighter fuels like grass, and it can offer a greater potential for extended combustion and heat output.

Understanding the different categories of fuels is critical for fire management and prevention planning, as it affects how fires behave and how they can be controlled. In contrast, the other choices include lighter fuels or materials that are not as dense, which do not fall under the heavy fuels category.