A disturbance is a temporary change in average environmental conditions that causes a pronounced change in an ecosystem. Disturbances often act quickly and with great effect, sometimes resulting in the removal of large amounts of biomass. Ecological disturbances may include fires, flooding, windstorms, plague outbreaks, earthquakes and even climate change. Human impact (anthropogenic disturbance) is evident within cities, constantly developing the built environment.
Some species are particularly suited for exploiting recently disturbed sites. Vegetation with the potential for rapid growth can quickly take advantage of the lack of competition and in most cases with the abundance of sunlight. Species that are well adapted for exploiting disturbance sites are referred to as pioneers or early successional species.