Every living organism on this planet is part of a food chain. What is a food chain? A food chain is the process in which different species exchange energy from one to another by eating each other. Consequently, all species are interconnected somewhere in the food chain. From plankton and vegetation to lions and humans, all the animals fit inside the chain.
On many occasions, the health of a species will depend on the survival of the species right under. At the end, we realize that the chain is quite fragile because everyone depends on each other, but not every species are strong enough to survive the change in their environment.
Throughout history, mistakes have showed that biodiversity can easily be destabilized. For example, British hunters in the 19th century decided to import European red fox and hare in Australia to practice their sport. Thinking that hare would eat grass and fox would chase the hare, the hunters didnít think further about the consequences of such a gesture.
Foxes started to chase other animals since it can feed on almost anything, which completely damaged the food chain that had been established in the region for many centuries. The population of many species declined after the introduction of the fox, and even animals on farms were now in danger of their attacks. The impact of the damages is measured in billions of dollars.
The fox can easily adapt itself to different ecosystem. Painting by Dave Todaro, http://nuvango.com/davetodaro
Other than human misjudgment, pollution can play a similar role in the destabilization of the biodiversity. When one element such as water, soil, vegetation or air is affected by pollution, the animals that depend on the ecological area to survive will disappear from it and so will the rest of animals that feed on it.
The impact starts a chain reaction on the biodiversity which can hardly be contained. That is why climate change has a huge impact on the Earthís biodiversity, because it modifies the ecological niche of every living thing on this planet. The polar bear is a known example, as they see their hunting season reduced due to global warming.