Chapter 9. Chapter 9: Biodiversity

How do genetic diversity, species diversity, and ecological diversity contribute to ecosystem function and services?

Why You Should Care

Genetic diversity of species is important to species because it is a safeguard against extinction. Cheetahs, for example, have become inbred to the point that genetic diseases and disorders have made them less fit for their environment. One reason that genetic diversity is important for humans is food security. Most major crops and food animals have only a few genetic varieties in extensive production, a tiny fraction of the potential variation. Most of these varieties are grown because they have some characteristic that makes them appealing for mass marketing, such as slow ripening that allows fruit to be shipped longer distances. Some researchers work to maintain "heirloom" or "old-fashioned" varieties of plants and animals so that there will be a source of variation should our current food species fail, something that is already happening with bananas, for example; a disease is killing off most of the banana plants around the world, and growers have been scrambling to develop a new resistant variety that ships well.

Just like genetic diversity improves the survival chances of a species, species diversity is a safeguard against the collapse of ecosystems. Although it isn’t desirable to lose any species, if an ecosystem has a diverse set of species and an extensive food web and network of other species interactions, it is less likely that losing any one species will lead to the ecosystem losing its normal functioning (unless, of course, that species is a keystone). Similarly, ecological diversity in an area ensures that there are a variety of functions and services provided for humans and other organisms. These services include clean air and water, attractive areas for recreation, erosion control, and nutrient cycling.

Drag and drop each ecosystem service to its category.