CPFM Fuels Management & Vegetation Flashcards

What is the 'fuel moisture of extinction' in fire behavior modeling?

Answer: The moisture level at which fuels will no longer sustain combustion

Fuel moisture of extinction is the threshold moisture content above which a fuel cannot sustain combustion regardless of heat input, used in fire behavior models to determine burnability.

Which common field method is used to estimate dead fuel moisture content during prescribed burn preparation?

Answer: Fuel moisture sticks (standardized wooden dowels weighed in the field)

Fuel moisture sticks are standardized wooden dowels that are weighed before and after field exposure; their weight change relative to oven-dry weight approximates the moisture content of similarly sized dead fuels.

At approximately what live fuel moisture percentage are grasses considered 'cured' and ready to readily carry fire?

Answer: Below 60–80%

When live grass fuel moisture falls below approximately 60–80%, grasses are considered cured — essentially behaving like dead fuels — and will readily ignite and carry fire.

What is the typical objective of a 'maintenance burn' in a fire-adapted ecosystem?

Answer: To periodically remove accumulated fuels and maintain ecosystem health on a regular cycle

Maintenance burns are conducted on a regular return interval to prevent dangerous fuel accumulations, sustain fire-adapted plant communities, and mimic natural fire cycles.

What does 'consumption' mean in the context of prescribed fire management?

Answer: The proportion or absolute amount of available fuel that is actually burned

Consumption is the percentage or tonnage of available fuel actually burned, which is critical for predicting smoke production, meeting fuel reduction objectives, and calculating post-burn fuel loads.

Which vegetation management challenge is prescribed fire commonly used to address in US rangelands?

Answer: Controlling encroachment of woody shrubs and trees into grasslands

Prescribed fire is a primary tool in US rangelands for controlling brush encroachment — the invasion of woody shrubs and trees into grasslands — restoring productivity and native grass diversity.