Ecological succession sounds automatic—a farm is abandoned or a glacier retreats, and eventually the ecosystem regains its original communities. However, as in the Channel Islands, “letting nature take its course” doesn’t always work, and ecosystems often need some help from restoration ecologists. If a disturbed ecosystem is simply left alone, what environmental conditions tend to favor natural succession, and what conditions may slow succession or even allow the ecosystem to remain permanently degraded?

Ecological succession sounds automatic—a farm is abandoned or a glacier retreats, and eventually the ecosystem regains its original communities. However, as in the Channel Islands, “letting nature take its course” doesn’t always work, and ecosystems often need some help from restoration ecologists. If a disturbed ecosystem is simply left alone, what environmental conditions tend to favor natural succession, and what conditions may slow succession or even allow the ecosystem to remain permanently degraded?