Up: Types of stochastic threats
Previous: Environmental stochasticity
Catastrophes are in one sense, merely an extreme form of
environmental stochasticity. It is, however, useful to distinguish
them for several reasons:
- Often distinguished as events happening at random intervals in
which a large proportion of the individuals in the population die.
- Even though catastrophic declines may occur very rarely, they
have a large impact on whether populations are able to persist.
- Catastrophes occur infrequently, and we're not likely to see one
or to see how large its effect is while we're watching. Even a
relatively long time-series may not include them. Nonetheless, if
catastrophes are big enough, meaning that they eliminate a large
enough fraction of the population, they may be the greatest threats
to a population's persistence, even if they occur only once every 50
or 100 years.