B.S.F. or B.Sc.F. Bachelor of Science in Forestry Bachelor of Science in Forestry: Forest Fire Ecology 5 — Questions and Answers
Question 1: Which metric is used to quantify the degree of departure from historical fire regimes in a given landscape?
- Fire Return Interval Departure (FRID) (Correct answer)
- Composite Burn Index (CBI)
- Keetch-Byram Drought Index (KBDI)
- Energy Release Component (ERC)
Correct answer: Fire Return Interval Departure (FRID)
Fire Return Interval Departure (FRID) compares the current fire-free interval to the historical mean fire return interval to assess how far a landscape has deviated from its natural fire regime.
Question 2: The Composite Burn Index (CBI) is a field-based metric used to assess:
- Probability of ignition from lightning
- Overall fire severity across multiple vegetation strata post-fire (Correct answer)
- Total carbon released per hectare during combustion
- Slope-adjusted rate of fire spread
Correct answer: Overall fire severity across multiple vegetation strata post-fire
CBI integrates burn severity observations across substrates (soil, understory, mid-story, overstory) into a single index ranging from 0 (unburned) to 3 (high severity).
Question 3: Which remote sensing product is most commonly used to map post-fire burn severity across large landscapes?
- Normalized Difference Vegetation Index (NDVI)
- Differenced Normalized Burn Ratio (dNBR) (Correct answer)
- Enhanced Vegetation Index (EVI)
- Soil Adjusted Vegetation Index (SAVI)
Correct answer: Differenced Normalized Burn Ratio (dNBR)
The differenced Normalized Burn Ratio (dNBR) compares pre- and post-fire Landsat shortwave infrared reflectance to map burn severity at landscape scales.
Question 4: What role does biological soil crust (biocrust) play in post-fire watershed hydrology?
- It accelerates overland flow by sealing soil pores immediately after fire
- It stabilizes soil and enhances infiltration but is often destroyed by fire (Correct answer)
- It produces nitrogen fixing compounds that restore soil fertility within days
- It prevents rill erosion by forming a rigid surface layer resistant to raindrop impact
Correct answer: It stabilizes soil and enhances infiltration but is often destroyed by fire
Biocrusts composed of cyanobacteria, mosses, and lichens stabilize soil and promote infiltration, but combustion destroys them, temporarily increasing runoff and erosion risk.
Question 5: In the context of the 'fire-climate-vegetation feedback,' how does increased fire frequency in boreal forests affect long-term albedo?
- Frequent fires maintain dense canopies that lower albedo and increase warming
- Frequent fires replace dark conifer canopies with lighter reflective young stands or shrubs, increasing albedo (Correct answer)
- Fire has no measurable effect on albedo because snow cover dominates winter energy balance
- Frequent fires deposit black carbon that permanently lowers albedo regardless of vegetation recovery
Correct answer: Frequent fires replace dark conifer canopies with lighter reflective young stands or shrubs, increasing albedo
High-severity fires replace dark-canopied spruce-fir stands with lighter deciduous shrubs or young trees, increasing surface albedo and potentially producing a regional cooling feedback.
Question 6: Which phenomenon describes the situation where fire suppression in dry mixed-conifer forests has led to dramatically increased tree densities and fuel loads compared to historical conditions?
- Forest densification syndrome
- Mesophication (Correct answer)
- Stand homogenization
- Overstory recruitment pulse
Correct answer: Mesophication
Mesophication refers to the transition of fire-adapted open forest ecosystems toward denser, more mesic conditions as shade-tolerant species recruit in the absence of regular fire.
Question 7: Under the US National Environmental Policy Act (NEPA), prescribed burn plans are typically documented in which type of analysis to comply with federal environmental review requirements?
- Categorical Exclusion (CE) or Environmental Assessment (EA) (Correct answer)
- State Environmental Impact Report (EIR)
- Biological Assessment (BA) only
- Timber Management Plan (TMP)
Correct answer: Categorical Exclusion (CE) or Environmental Assessment (EA)
Most prescribed fire projects on federal lands are analyzed under a Categorical Exclusion or Environmental Assessment, with a full EIS required only for large or controversial projects.
B.S.F. or B.Sc.F. Bachelor of Science in Forestry Bachelor of Science in Forestry: Forest Fire Ecology 5
Which metric is used to quantify the degree of departure from historical fire regimes in a given landscape?