What happens when non-living factors in an ecosystem are altered, such as rainfall or air quality?
- An ecosystem is a living system interacting with its physical habitat.
- Changes in biotic and environmental factors can be devastating.
- If a water source dries out, a wetland can turn to barren mud flats.
- Pollution is changing our climate and disrupting many ecosystems.
An ecosystem is a living system of organisms interacting with their physical habitat, so changing the environment can have far-reaching effects.
Altering just one non-living abiotic factor – like soil composition, or air quality – can impact on the whole ecosystem.
Some of the most dramatic and immediate effects are seen when water resources are changed.
Colorado River, USA
The Colorado river starts in the Rocky Mountains.
It carved out the Grand Canyon and once flowed into the sea at the Gulf of California, Mexico, creating a vast wetland ecosystem.
Colorado River Delta: Once covered over 8,000 km2
But in the first half of the 20th century, many huge dams were constructed upstream, to deliver water to cities and agriculture across the USA.
Now so much water is diverted, the river no longer meets the sea.
Colorado River – ends 60km before ocean
Where there was once a rich wetland ecosystem, supporting large populations of plants, aquatic life, and birds, and an indigenous people reliant on fishing, there are now just barren mudflats.
Over 90% of the wetlands have been removed because of changes to the river's course thousands of kilometres away.
This threatens the ecosystem of the Colorado river delta with total collapse.
Pollution is another major abiotic factor changing ecosystems.
It can have direct effects – for example, on lichen, which can only grow in clean air or on wildlife caught in water pollution, which can devastate local ecosystems.
But pollution also threatens the stability of our whole planet's ecosystem.
It's changing our climate – which is the biggest factor of all affecting species' diversity.
And when the number of different species reduces, it leaves an ecosystem much more vulnerable to collapse.
The true effects of abiotic changes might not be seen immediately, but they can change things forever.