Final answer:
Natural disturbances like lightning can lead to temporary changes in an ecosystem, while human-related disturbances such as pollution can cause more long-lasting harm, both of which concern conservationists due to their impact on the environment.
Step-by-step explanation:
Two types of disturbances that concern conservationists are natural and human-related disturbances. Lightning is an example of a natural disturbance, while pollution represents a human-related disturbance. Both types are alarming to conservationists because they have significant impacts on ecosystems. Natural disturbances like lightning can lead to forest fires, which are part of a process known as succession, where the affected area eventually recovers. However, human-related disturbances such as pollution, deforestation, and overfishing can cause longer-term or potentially irreversible harm to ecosystems, which conservationists strive to prevent and mitigate.