大象传媒

Monitoring and maintaining the environment - OCR Gateway Environmental changes - distribution of organisms

Biodiversity is a measure of how many different species live in an ecosystem. Human activities like changing land use, deforestation and peat bog destruction reduce this.

Part of Biology (Single Science)Global challenges

Environmental changes affect the distribution of organisms

Effect of climate change on the small tortoiseshell butterfly

As the Earth's mean temperature increases, the habitats that organisms can occupy are changed. For the small tortoiseshell butterfly, it is estimated that by 2080 most of central Europe will not be habitable by the butterflies. However, they will gain suitable habitats in northern Europe.

Effect of water pollution in the Yangtze River

The Yangtze River in China is home to 350 fish species, a high crab biodiversity and over 160 amphibian species. It is also the sole habitat of many species including the Finless Porpoise and the Chinese River Dolphin.

Because of increasing levels of pollution in the river, the distribution of species in the river is changing as many are no longer able to live there. Sightings of the Chinese River Dolphin have become such a rarity that it is now believed to be extinct.

A Chinese River Dolphin cresting to allow itself to breathe.
Image caption,
The Chinese River Dolphin is now believed to be extinct, caused by pollution of its habitat