What are the effects of natural disasters?

The effects of natural disasters depends on the type of natural disaster and the ecosystem the natural disaster occurs in. A hurricane in a tropical forest is going to have a different impact than an ice storm in a boreal forest which will have a different impact than a drought in a grassland.

Effects can include removal or degradation of soil, loss of vegetation, loss of weak or old individuals at the population level, migration of surviving populations, change in runoff patterns, and potentially succession. Natural disasters can also open up ecological niches to invasive species and make it easier for them to spread.

If the natural disaster is severe enough, it may destroy a significant amount of biotic life in an ecosystem and the succession or equilibrium of the ecosystem may be disrupted.

For example, if a tropical forest experiences a hurricane that destroys the majority of trees with large canopies, this will create new spaces for any tree species that did not have the necessary space to grow. By opening up the canopy and creating these gaps, species that are less shade-tolerant are able to grow. Thus, the hurricane has changed the forest composition.

A fire could destroy a mature forest, resulting in the ecosystem returning to the primary stage of succession, where quick-growing and hardy species colonize the area. See the image below.

To learn more, refer to these related Socratic answers: what is ecological succession, how does a forest recover after a fire, and how do ecosystems respond to natural disasters such as fires and floods?.