What is the term for an ecological event that disrupts an ecosystem significantly?

The term used to describe an ecological event that significantly disrupts an ecosystem is termed a disturbance. Disturbances can take various forms, such as natural events like wildfires, hurricanes, floods, or human activities such as deforestation and pollution. These events can lead to changes in the structure and function of an ecosystem, influencing species composition, nutrient cycling, and habitat availability.

Disturbances can be either natural or anthropogenic and can vary in intensity and frequency. They can lead to a reset in ecological succession, allowing some species to thrive while others decline. For instance, after a forest fire, the area may see an initial colonization of pioneer species, which can eventually lead to a mature forest ecosystem over time.

In contrast, concepts like genetic drift refer to changes in allele frequencies in a population due to random sampling, adaptation pertains to changes in traits that enhance survival and reproduction, and ecosystem services involve the benefits that ecosystems provide to humans, such as clean water, food, and climate regulation. None of these terms captures the essence of an event that disrupts ecosystem dynamics as effectively as disturbance does.