Stability and Diversity in Ecosystems

August 3, 2007
Stability and Diversity in Ecosystems
Sparkling Lake, Wisc., after removal of invasive rusty crayfish: its ecosystem once again sparkles. Credit: Steve Carpenter, U. of Wisc.-Madison

Is biodiversity important for predicting human impacts on ecosystems? If diverse ecosystems were as a consequence more stable, the answer would be yes.

However, stability is not one, simple property of an ecosystem and there is no one, simple relationship between diversity and stability, say ecologists Tony Ives and Steve Carpenter of the University of Wisconsin at Madison.

In the last 20 years, ecologists have performed experiments on diversity and stability, manipulating diversity (number of species) at small scales, then measuring one of several kinds of stability.

While these studies have taught us a lot about how diversity affects some types of stability, they don't necessarily tell us how stable ecosystems will be against human impacts, say Ives and Carpenter.

Ecologists should turn the question on its head, the researchers believe: rather than focusing on how diversity affects stability, scientists might make faster progress by focusing on stability first.

"Humans don't change 'just' biodiversity," said Ives. "Humans cause major environmental changes to ecosystems, like acidifying lakes or cutting down forests, with changes in biodiversity often a by-product.

"Rather than how biodiversity affects stability, we should be asking how environmental change affects the stability of many aspects of ecosystems, including diversity."

People often equate stable with good, unstable with bad, said Carpenter. But that thinking may be dead wrong.

"Anybody who has fought the very stable population of dandelions on their front lawn," he said, "or the increasingly predictable algal blooms in lakes like Mendota in downtown Madison [Wisconsin], knows that stable isn't necessarily good. Everyone would like to make components of ecosystems like these unstable enough to disappear."

In fact, environmental management is the management of stability, destabilizing unwanted situations while stabilizing preferred situations, Carpenter said.

Ives' and Carpenter's conclusion is that ecologists are still far from understanding how many ecosystems work. There are no short-cuts, they say, and it might be impossible to extrapolate from one ecosystem (or one experimental plot) to other ecosystems.

"The best argument for preserving biodiversity is still the cautionary principle," said Ives. "Given that we know little, it makes sense not to change much."

Ives and Carpenter published a review paper on stability and diversity of ecosystems in the journal Science on July 6, 2007.

Source: NSF

Explore further: Higher plant species richness may not be enough to protect ecosystems from the worst impacts of climate extremes

Related Stories

Mapping functional diversity of forests with remote sensing

November 13, 2017

Productivity and stability of forest ecosystems strongly depend on the functional diversity of plant communities. University of Zurich researchers have developed a new method to measure and map functional diversity of forests ...

Old fish few and far between under fishing pressure

September 14, 2017

Like old-growth trees in a forest, old fish in the ocean play important roles in the diversity and stability of marine ecosystems. Critically, the longer a fish is allowed to live, the more likely it is to successfully reproduce ...

New conservation method empowers indigenous peoples

October 11, 2017

For many in the Western world, the conventional notion of "development," or the idea that societies progress through industrialization and agricultural intensification, goes unquestioned: it provides people with housing, ...

Recommended for you

East Antarctic Ice Sheet has history of instability

December 13, 2017

The East Antarctic Ice Sheet locks away enough water to raise sea level an estimated 53 meters (174 feet), more than any other ice sheet on the planet. It's also thought to be among the most stable, not gaining or losing ...

Hydraulic fracturing negatively impacts infant health

December 13, 2017

From North Dakota to Ohio to Pennsylvania, hydraulic fracturing, also known as fracking, has transformed small towns into energy powerhouses. While some see the new energy boom as benefiting the local economy and decreasing ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.