Dieback

views updated

Dieback

Dieback refers to a rapid decrease in numbers experienced by a population of organisms that has temporarily exceeded, or overshot, its carrying capacity . Organisms at low trophic levels such as rodents or deer, as well as weed species of plants, experience dieback most often. Without pressure from predators or other limiting factors, such "opportunistic" species reproduce rapidly, consume food sources to depletion, and then experience a population crash due chiefly to starvation (though reproductive failure can also play a part in dieback). The presence of predatorsfor instance, foxes in a meadow inhabited by small rodentsoften results in a stabilizing effect on population numbers.