Natural Disturbance types

Question 1

NDT1

fire interval, stand types, size of natural disturbances, recommended management

Answer 1

RARE STAND INITIATING EVENTS (ICHvk, MH subzones on coast)
-uneven ages or multi storied even aged
-gaps created by individual tree deaths or small disturbances
-disturbance return interval 250-350 years
-stand maintaining surface fires
RECOMMEND: seral stages should occur in a variety of patch sizes within landscape unit

Question 2

NDT2

fire interval, stand types, size of natural disturbances, recommended management

Answer 2

INFREQUENT STAND INITIATING EVENTS (ICHmw1(golden), SWB zones up north)

• usually even aged
• gaps created by wildfires of mod. size (20-1000ha)
• disturbance return interval 200 yrs
• seral stages should occur in a variety of patch sizes within landscape unit
• keeping snags and vets and CWD important for biodiversity

Question 3

NDT3

fire interval, stand types, size of natural disturbances, recommended management

Answer 3

FREQUENT STAND INTIATING EVENTS(ICHdw, ESSFdk)
-mosaic of even aged stands of different ages
-wildfire gaps large-100 000 to 200 000 ha
-average fire size 300 to 6000 ha
-DRI 100-150 yrs
Fd most fire resistant species in this NDT
-seral stages should occur in variety of patch sizes within landscape unit
-clustered harvest pattern using large aggregated harvest units

Question 4

NDT4

fire interval, stand types, size of natural disturbances, recommended management

Answer 4

FREQUENT STAND MAINTAINING FIRES (IDFmz, PP subzones)
-non forested or even aged stands with vets
-includes grasslands, shrub lands, dry open forest
-surface fire interval 4-50 years
crownfire interval 150-250 yrs
most of this NOT rangeland
Rangeland should be managed to 50% production, more allowed if plan in place
partial cutting, small clear cuts (40-60ha)

Question 5

NDT5

fire interval, stand types, size of natural disturbances, recommended management

Answer 5

ALPINE TUNDRA AND SUBALPINE PARKLAND ECOSYSTEMS

• above or immediately below treeline
• short, harsh growing seasons
• vegetation patterned by topography
• fire disturbance is patchy and can have dramatic effect onthese sensistive ecosystems
• 85% of each ecosystem should be maintained in late seral or climax condition
• manage livestock so trails not created and no browse damage

Question 6

Fire suppression and biodiversity in NDT4

Answer 6

History of periodic surface fires consumed woody fuels, rejuvenated most herb/shrub species, selected thinned younger stands, rasied height to live tree crowns

• historically, fire responsible for keeping vegetative species composition and forest stand structure, also for regulating CWD loading
• suppression caused fuel loading = crown fires
• use fire as tool to control brush and tree invasion
• rehab like under burning on stands that are dominated by Fd