Disturbance
- Disturbance (撹乱)
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Major catastrophic events originating in the physical environment - events which cause abrupt structural change in communities
(White 1979)
Problems
- There is a gradient from minor to major events rather than a uniquely definable set of major catastrophes for each kind of disturbance
- Some disturbances are initiated or promoted by the biotic component of the system
- Three parameters on disturbances
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Disturbance regime = determined by the type and three parameters to characterize disturbances shown below:
Scale (size)
Frequency (interval)
Intensity (magnitude) - Type
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Natural disturbance
Human disturbance (human-induced disturbance, or anthropogenic disturbance) - Natural disturbance
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Volcanic eruption
Landslide
WildfireForest fire at Alaska 
Sprouting after fire at Boston Creek (May 11 2005) Moderately disturbed site. Peat moss still remained on the forest floor. Intensively disturbed site. Peat was completely burned out by fire. Snags could not keep standing. - Human disturbance
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Mining, e.g., coal, bauxite, and peat
Establishment of skislope
Reclamation for cultivation, such as meadow and paddy field
Grazing by cattle, e.g., yak - References
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- Grime's triangle
- biological invasion (生物学的侵入)
- White PS. 1979. Pattern, process, and natural disturbance in vegetation. Botanical Review 45: 229-299