Imagine a football team made up of nothing but quarterbacks. Even if all were Heisman Trophy winners, they probably not do well in a game. In fact, I would expect them to be trounced by a team with a mix of average quarterbacks, receivers, defenders and kickers. Studies show that diversity in the workplace can increase productivity (Barrington, Troske 2001). A group of people of different genders, ages, races and cultures tends to be more innovative and adaptable. Diversity is also important in the natural world.
Biodiversity is the number and variety of plant and animal species within a habitat. There are many biological, economic, aesthetic, medical, recreational and scientific advantages, direct and indirect, associated with biodiversity.
Populations of the Fiji Banded Iguana are declining as a result of habitat loss; agricultural development; competition from feral goats predation by cats and rats, and illegal exotic animal trade. Wikimedia Commons photo.
An ecosystem that is biologically robust is more likely to survive and thrive. That is why biodiversity is often used as a measure of the health of an ecosystem. Different life forms occupy different niches in the ecosystem. For example, microbes break down leaves, which become soil on which a new tree grows. An insect eats a growing leaf, a bird eats the insect, and so on. Each organism plays a different role in the cycle, and depends on other parts of the web of life to live.
Genetic diversity is also valuable. Just as inbreeding among the royal families of Europe spread hemophilia, a lack of genetic diversity negatively impacts the long term sustainability of both plant and animal communities. Think about what would happen if an entire country depended almost exclusively on one variety of plant – say a potato – for food. If that monoculture were attacked by a fungal blight that spread easily from one potato plant to another, a large chunk of the population could starve. That is exactly what happened from 1845-1860, when more than a million people died in Ireland during the Great Famine.
Here is another scenario, from an essay by Paul and Anne Ehrlich. As you are boarding a plane, you notice a workman busily prying rivets from its wing. You ask him what the heck he is doing. He says the airline has discovered it can sell the rivets for two dollars apiece. You ask how he knows he won’t fatally weaken the wing by removing the rivets. He tells you not to worry – he’s taken lots of them off already, and the wing hasn’t fallen off yet. Besides, there are plenty more. He’s so unconcerned that he plans to fly on that airplane too.
You probably would chose not to fly on that particular plane. But neither you nor the rivet popper can avoid being on Spaceship Earth. Those rivets are like the different species on our planet, some of which are rapidly going extinct. Each year, scientists estimate that as many as 50,000 plant and animal species disappear. Most die off, says University of Minnesota ecology professor David Tilman, because of human activity. We don’t really know what the consequences will be.
That is why scientists are urging us to pay more attention to preserving and enhancing biodiversity. What can you do as an individual? As Mohandas Gandhi said, “You must be the change you wish to see in the world.” Here are some ideas.
- Landscape with a mix of native plants.
- Help rehabilitate or restore a degraded area of forest, grassland or wetland near your home.
- Help control invasive species of plants and animals.
- Use pesticides in or around your home only when absolutely necessary, in the smallest amounts possible.
- Do not harass or disturb animals or plant life in the wild.
- Keep pet cats indoors.
- Donate unused binoculars for distribution to biologists.
Harness your power as a consumer.
- Purchase products made or recycled materials or grown and harvested in a sustainable manner.
- Do not buy anything made from endangered or threatened animal species.
- Do not buy plants or pets taken from the wild.
- Help reduce the depletion of marine species by eating only certain types of fish and shellfish – download a pocket guide at http://tinyurl.com/87qo52.
- Buy organically grown products.
- Drink shade-grown coffee.
- Encourage businesses you patronize to do the same.
- Support organizations and laws that help preserve unique habitats, open space and large tracts of forestland.
These actions may seem small compared to the scope of the problem. But even microbes can make a difference in our world.