A primary disturbance is essentially a natural environmental disaster. For example, a volcano erupting is a primary disturbance. The eruption disrupts the local environment, or even sometimes the global environment. Therefore, a primary disturbance can have an initial impact on the local flora and fauna and then a long-lasting impact in local and widespread flora and fauna. In some cases, it can even have an effect on the atmosphere.
Examples of primary disturbances
The aforementioned volcanic eruption is a good example of a primary disturbance. It can cause other ecological disturbances, such as forest fires and earthquakes. Lightning storms and other atmospheric disturbances are also possible with volcanic eruptions.
Earthquakes are primary disturbances that tend to have less of an immediate and lasting impact on an area's ecology than many other ecologic disturbances. However, they can and do cause damage to the homes of both animals and people. They can also cause tsunamis, which can be devastating.
Forest fires are primary disturbances that can be small and contained or widespread and lasting for weeks and potentially longer. They have a severe immediate impact, as they affect air quality and cause destruction. They are capable of reducing flora and fauna numbers, as well as eliminating habitats.
Other primary disturbances include landslides and floods. Every primary disturbance has a variety of potential causes and outcomes. They are each treated according to the ecological impact and dangers they present.
Immediate effect of primary disturbances
When it comes to ecologic disturbances, the immediate effects depend wholly on what sort of disaster is occurring. The effect of an earthquake is very different from the effect of a flood. They both may have death tolls and habitat loss, but they reach those ends in different ways.
The immediate effects of a volcanic eruption include burning to death, asphyxiation, earthquakes, widespread forest loss, forest fires, lowered population of animals (including humans) and much more. If the eruption is big enough, such as with Pompeii, entire landscapes can be buried in the resulting volcanic lava flows and ash.
A landslide may seem less hazardous than, say, an earthquake or a volcanic eruption, but these primary disturbances are very dangerous. They can move homes, bury them, pollute major water sources, move roads and kill everything in their paths. They are among the worst natural disasters.
Flooding, whether caused by torrential downpours, broken dams or tsunamis, all do the same thing: they drown everything in their paths. Anything lucky enough to get out of the way, and to find a way to float or get above the rising water, will make it. Everything else either gets wet or destroyed, depending on the severity of the flood.
Long lasting effects of primary disturbances
The primary disturbances most likely to cause lasting effects are volcanoes and earthquakes. Volcanoes can change the climate for years if the eruption pollutes the atmosphere enough. Earthquakes can change landscapes and cause tsunamis that change landscapes. In fact, earthquakes and volcanic eruptions shape the Earth without any regard for whether we are standing there when it happens.