Disturbance

n. interference, distraction; something which disturbs; unrest

In ecology, a disturbance is a temporary change in average environmental conditions that causes a pronounced change in an ecosystem. Outside disturbance forces often act quickly and with great effect, sometimes resulting in the removal of large amounts of biomass. Ecological disturbances include fires, flooding, windstorm, insect outbreaks, as well as anthropogenic disturbances such as forest clearing and the introduction of exotic species [1]. Disturbances can have profound immediate effects on ecosystems and can, accordingly, greatly alter the natural community. Because of these and the impacts on populations, these effects can continue for an extended period of time.
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Noun
1. activity that is an intrusion or interruption; "he looked around for the source of the disturbance"; "there was a disturbance of neural function"
(synonym) perturbation
(hypernym) activity
(hyponym) fuss, trouble, bother, hassle
2. an unhappy and worried mental state; "there was too much anger and disturbance"; "she didn't realize the upset she caused me"
(synonym) perturbation, upset
(hypernym) agitation
(derivation) disturb, upset, trouble
3. a disorderly outburst or tumult; "they were amazed by the furious disturbance they had caused"
(synonym) disruption, commotion, stir, flutter, hurly burly, to-do, hoo-ha, hoo-hah, kerfuffle
(hypernym) disorder
(hyponym) convulsion, turmoil, upheaval
4. a noisy fight
(synonym) affray, fray, ruffle
(hypernym) fight, fighting, combat, scrap
5. the act of disturbing something or someone; setting something in motion
(hypernym) motion, movement, move, motility
(hyponym) circus, carnival
(derivation) touch, disturb
6. (psychiatry) a psychological disorder of thought or emotion; a more neutral term than mental illness
(synonym) mental disorder, mental disturbance, psychological disorder, folie
(hypernym) disorder, upset
(hyponym) anxiety disorder
(classification) psychiatry, psychopathology, psychological medicine
7. electrical or acoustic activity that can disturb communication
(synonym) noise, interference
(hypernym) trouble
(hyponym) clutter

(n.)
Violent agitation in the body politic; public commotion; tumult.
  

(n.)
The hindering or disquieting of a person in the lawful and peaceable enjoyment of his right; the interruption of a right; as, the disturbance of a franchise, of common, of ways, and the like.
  

(n.)
Confusion of the mind; agitation of the feelings; perplexity; uneasiness.
  

(n.)
An interruption of a state of peace or quiet; derangement of the regular course of things; disquiet; disorder; as, a disturbance of religious exercises; a disturbance of the galvanic current.
  

Any event or series of events that disrupt ecosystem, community, or population structure and alters the physical environment.