Like HowStuffWorks on Facebook!

How does biodiversity help an ecosystem?

Biodiversity in Danger
Practices like clear-cutting have helped to drastically amp up the extinction rate.
Practices like clear-cutting have helped to drastically amp up the extinction rate.

Animal and plant species die off all the time. It's how the biological world rolls. However, things have changed dramatically in recent decades. According to some scientists, Earth is currently in the midst of its sixth mass extinction. The last major extinction occurred some 65 million years ago, when a large asteroid slammed off the coast of Mexico, killing off the dinosaurs and most everything else. Today, scientists say the extinction rate is as much as 1,000 times faster than what should be natural [source: University of Copenhagen].

Who's to blame? Look in the mirror. There are more than 7 billion of us in the world, all competing for limited natural resources. In 40 years, there could be another 2 billion people, each relying on the planet for food, energy, land and water [source: Eng]. Whether we like it or not, Earth can only sustain so many people. The building of new roads, dams, bridges, farms and ranches all destroy habitat. When there's construction, even on a small scale, animals move away or are killed outright.

The loss of biodiversity has gotten so bad that The World Resources Institute says more than 80 percent of the planet's forests have already been destroyed. In West Africa, humans have ruined 90 percent of the coastal rain forests since 1900. The Amazon rain forest, which is spread across nine South American countries, was once bustling with plants and animals, all untouched by civilization. Yet, several decades of clear-cutting and farming have devastated the region [source: National Geographic].

And it's not just clear-cutting that's driving the loss of biodiversity. Land and water pollution is killing off many species. If you drive a gasoline-powered car, turn on a light that uses electricity generated by a coal-burning power plant or burn fuel oil to heat your home, you're contributing to this mass extinction. Overfishing, over-farming and a ton of other human activities are also driving the loss of biodiversity [source: Natural History Museum].

Although it might seem that alleviating the problem is beyond the average person, think again. We can all do something to help stem the tide of biodiversity loss. We can build birdhouses and bat boxes to attract these high-flying animals. We can plant native flowers and trees in our gardens. Bumblebees are dying off at a terrific rate. We can plant flowers that attract them, giving them a place to pollinate and to rest. Governments can enact legislation keeping bio-sensitive areas off limits or putting caps on greenhouse gas emissions, which fuel global warming [source: Midlothian].

As for me, well, I'm planting a meadow of tall grass and more wildflowers behind the house. It's costing me a bundle — I have to take down many damaged and dead trees — but the planet and the monarchs are worth it.