Biodiversity

Lina is visiting India, trekking through a tropical rainforest. It's warm, humid, and bustling with life. There are so many different plants and animals here in the rainforest! We say there's a great variety, or diversity, of species. And if you look closely, you'll find that it's not just the species that are more diverse here in the rainforest.

Within each species, there is also great variety, with many different types of each plant and animal. That means there is tremendous genetic variation within the species. As you trek through the jungle, you might also notice that it consists of several different ecosystems. So, there's a diversity of ecosystems as well. These three things...

Species diversity, Genetic diversity, and Ecosystem diversity, Genetic diversity, and Ecosystem diversity, ... together create biological diversity, or biodiversity. Different places have different levels of biodiversity. Places near the equator tend to have greater biodiversity, because of the warm climate... ... as long as there is enough water.

Heat and water, drive biodiversity. Of course there's biodiversity in the water as well. Off the warm coasts of the Western Pacific you'll find the highest marine biodiversity. That means there's a great variety of species, genes, and ecosystems under the surface there. Biodiversity is rather nice if you're hiking, giving you many plants and animals to spot.

But it's way more than a nice thing. Biodiversity is crucially important for our survival. We get so many things we need from the ecosystems in nature around us. Raw materials, like wood, rubber, food, or ingredients for medicine. And we get ecosystem services too, like a stable climate, clean air and fresh water, decomposition of material, and pollination of plants.

So, when an ecosystem is threatened for some reason, we not only risk losing a nice spot to hike. It's a serious threat to those things we need for survival! And this is where biodiversity comes in. Biodiversity makes nature more robust, more resilient, to threats. If you go to a rainforest, with its vast biodiversity, and remove one species of plant or animal completely, chances are it won't have a huge impact!

Most likely, other plants and animals will fill its place, and the overall balance of the ecosystem will remain. But there are some species, that are more important than others. Take coral for instance. It's a marine invertebrate animal, that gives shelter to a host of other plants and animals... ... and these plants and animals are in turn feeding even more species.

When coral is threatened, by pollution or a warmer climate for instance, it affects almost all marine life in that region. A species that has this role in an ecosystem is called a keystone species. Other keystone species include the jaguar, in South America, and the sea otter in the Pacific. When a keystone species is removed, the consequences are vast, hard to predict, and very difficult to correct. In places with low biodiversity, like the arctic tundra, almost any species is a keystone species.

Places like that are more vulnerable, as loss of any single species can disrupt an entire ecosystem. So, when we do things to the environment that reduces biodiversity, we increase the risk for other, bigger problems, in the future. There are many reasons why biodiversity is reduced around the world: Loss of habitat for animals Invasive species Climate change Over grazing, over farming, and over fishing Pollution and emissions The American biologist E.O. Wilson said it like this: "The one process ongoing that will take millions of years to correct is the loss of genetic and species diversity by the destruction of natural habitats. This is the folly that our descendants are least likely to forgive us."