Pioneer and successional plant communities are said to change over periods from 1 to 500 years. These changes—in plant numbers and the mix of species—are cumulative. Climax communities themselves change but over periods of time greater than about 500 years.
The climax community would be considered the most stable, since, by definition, it changes the least over time. Alternatively, stability can be defined as the speed with which an ecosystem returns to a particular form following a major disturbance, such as a fire.
Even if the new population is of a different species, it can approximately fill the niche vacated by the extinct population and keep the food web intact.
極盛期の群落は、時間の経過に対して最も変化が少ないため、定義上、最も安定していると考えられるだろう。一方、安定性は、火事などの大きな障害の後に、生態系がある特定の形態に戻るスピードと定義できる。
新しい個体群が異なる種であるとしても、絶滅した個体群によって空白となった生態的位置をほぼ埋めることができるので、食物網は損なわれない。