Chapter 7 Flashcards
Define FOE’s
Occur at the time of the fire or w/in seconds/minutes after. Are a direct result of combustion process. Direct result of fire, pre-fire conditions, and fire environment.
Define SOE’s
Occur over longer time frame. Days, months, decades. Indirect result of fire, weather, postfire insect interactions, land use, seed availability.
Define ecosystem memory
The behavior and spread of fire on a landscape will depend in part on the legacy of past fire events. Each fire alters the conditions for the next fire in the same location. In AB, fires tend to be constrained by the boundaries of prior wildfire disturbances.
Define fire prescription
Set of conditions under which a fire will be ignited, in order to meet management objectives.
List four examples of FOE’s
Plant injury/mortality, smoke production, soil heating.
List four examples of SOE’s
Soil erosion, smoke dispersion, veg succession.
List three factors that influence post-fire tree mortality in a surface fire regime
Crown damage, cambium damage, HSB, and DBH
Describe the natural cycle of crown fire and subsequent B. spruce regen
Fire prompts dispersal of semi serot cones from aerial seed bank. Individuals that est 10-15 years post fire make up majority of stand that burns in next fire, which occurs 80-150 year intervals. Takes 2-3 decades for b. spruce to reach reproductive maturity and have viable seed available for post-fire est.
Describe how fire return intervals influence B. spruce regen failure
- Constraints on seed germination in unburned stands (cycles of seedling recruitment and stand renewal primarily restricted to short periods of establishment on seed beds exposed after fire) - Fire returns too quickly, killing seedlings?
- Historical factors that reduce seed stores and post-fire seed availability can dramatically alter patterns of post-fire stand recruitment and dominance
Describe how the landscape mosaic of patches that consist of diff age stands, stand/fuel type, and diff time-since-fire influences fire-veg dynamics in an area
Affects intensity and ROS. Young stands = less fuel = less intense fire, vice versa for older stands.