Fire Regimes: Past and Present Flashcards
1
Q
Lightning
A
- Can have both + and - charges
2
Q
Positively charged lightning
A
- Covers ~5% of lightning strikes
- Most common origin of wildfires (much more powerful than negatively charged lightning)
- Continuous current (concentrates energy and increases probability of fire ignition)
3
Q
Negatively charged lightning
A
Occurs mostly in winter outside regular fire season
4
Q
Fire intensity
A
Amount of energy/heat released per unit of fireline
5
Q
Fire severity
A
Degree of environmental change caused by fire
6
Q
Intensity vs. severity
A
High intensity does not equal high severity (and vice versa)
7
Q
Residence time
A
Period of flaming combustion
8
Q
Modulators of fire regimes
A
- species and structure
- seasonality
- frequency
- spatial pattern (i.e. refugia)
9
Q
Historical range of variation (HRV)
A
- Conditions of functional, healthy ecosystems/landscapes
- Ecological reference against which contemporary and future conditions can be evaluated to determine status, trend, and magnitude of departure from the past
10
Q
Dendochronology
A
- Fire scars: marks left on ring of a year when a fire resistant tree was damaged by fire but survived
- Forest age structure methods: coring trees to identify germination dates
11
Q
Sediment cores
A
Microscopic fossil charcoal
12
Q
Determiners of long-term fire patterns
A
- climate/weather patterns
- ignition sources
- vegetation (fuel)
- landscape characteristics
- humans
