THREATS TO ECOSYSTEMS
Factors Causing Extinction
Threats to Ecosystems - Introduction
The purpose of this section is to summarise some of the factors that cause major changes to ecosystems and look at what kind of impacts humanity induces on various ecosystems.
Ecosystems around the world today are not only under threat from humanity's activities, but many major ecosystems are already suffering devastating consequences from these activities.
Some ecosystems are subject to natural disturbance such as earthquakes, tsunamis, fires and volcanic eruptions.
Disturbance in nature is not necessarily a bad thing, but a normal part of the natural world and its cycles. Ecosystems change all the time in response to these disturbances.
The abundance and distribution of species can change if major conditions in the environment are altered.
Part of what constitutes a threat to an ecosystem involves species extinctions. If a species does go extinct, it is not simply a loss nor is it a struggle for that species' survival that ends. Rather, it represents the sum total of that species' role in the ecosystem, being terminated. Sometimes a substitute emerges to fulfil that role, but it may do a poorer job or creates unpleasant side effects for the whole system.
Specific examples of species extinction are useful to discuss because it helps raise awareness of their roles in ecology and is particularly useful in highlighting the factors that lead a species to extinction.