The distribution of a species is where it is found in an ecosystem. Environmental changes affect distribution because each species is adapted to certain conditions. The changes include temperature, the availability of water and the composition of atmospheric gases.
The changes may be seasonal, geographic or caused by human interaction. A seasonal change is one that happens through the year, for example a cold winter. When temperatures fall, some animals migrate to warmer areas, so they are found in different places at different times of year. A geographic change is a difference between places, such as a dry desert and a wet rainforest. Human interaction includes the release of gases that change the composition of the atmosphere, for example carbon dioxide from burning fuels, which can raise temperatures and shift where species can live.
Less water makes it harder for plants to grow, so they can survive only where water is available, and the animals that feed on them move or die out. Gases matter too, because a change in the gases in the air or the water can make a habitat unsuitable for the species that live there.
You may be given information, such as a table or map, and asked to evaluate the impact of a change. Say what the change is, say which species are affected and how their distribution changes, and use the data to support your answer.