Disturbances are ecosystem processes which affect the composition, structure and function with in an ecosystem. Their effects include changes to parent material, soil, hydrology and the destruction of biota all of which than lead to alterations in species composition, structure and ecosystem function. Disturbances also promote changes in the mutulaistic and competitive nature between organisms which than influences the rate of vegetation change and therefore succession. Natural disturbances such as fire, insects and diseases and wind have shaped the landscapes and vegetation found in all ecosystems.

In addition to the natural disturbance factors which shape our ecosystems, we also must consider the disturbances caused by humans. We will discuss the different types of disturbances as they relate to secondary secession later in this lesson.