A disturbance is defined by the community change it produces, not by the agent.
Evidence
We can differentiate among the several types of disturbance processes that influence opportunities for species to become established in grasslands. Certain phenomena in the forest system (e.g., droughts) are not ordinarily thought of as disturbance agents, but disastrous windstorms with a return time of a thousand years or so (Canham and Loucks, 1984) are disturbances. The reverse may be true in grasslands: individual windstorms are usually not a disturbance, but a drought may be. The difference, apparently, is the extent to which a qualitatively different community emerges following the event. By such a criterion, a drought lasting for 2 years in a community characterized by many annuals and biennials can produce considerable change in the community and must qualify as a disturbance. — S. T. A. Pickett and P. S. White, eds., The Ecology of Natural Disturbance and…, 568
Categorization
- DEFINE: Operational definition of disturbance: an agent counts only if a qualitatively different community follows — ecosystem-relative, not agent-relative.
- XREF: Directly parallels the definitional work in Soundscape’s breakpoint/disturbance framing and the forest chapters’ gap definitions. — connects to: Disturbance is an act of renewal when its frequency is balanced — Robin Wall Kimmerer, Gathering Moss: A Natural and Cultural…, 305; Deviance is defined by social response, not the act itself; Biological agents and man-caused change both sit on one disturbance continuum. — S. T. A. Pickett and P. S. White, eds., The Ecology of Natural Disturbance and…, 1109 (+2 more)
- QUESTION: This functional definition could reshape how ‘disturbance history’ is inferred from present landscape — worth chasing how drought-driven change reads in field evidence.
Broader Connections
- Whether an event is a disturbance depends on the receiving organism
#corroborates(0.90) — S. T. A. Pickett and P. S. White, eds., The Ecology of Natural Disturbance and…, 1030 - Deviance is defined by social response, not the act itself
#responds-to(0.85) - Disturbance is an act of renewal when its frequency is balanced
#expands(0.80) — Robin Wall Kimmerer, Gathering Moss, 305 - The manner of demolition, not just the demolition, destroyed a community’s will to resist
#exemplifies(0.80) — Robert A. Caro, The Power Broker, 3728 - Biological agents and man-caused change both sit on one disturbance continuum.
#qualifies(0.75) — S. T. A. Pickett and P. S. White, eds., The Ecology of Natural Disturbance and…, 1109