Scientists say biodiversity is crucial to ecosystem productivity

Apr 24, 2008
Scientists say biodiversity is crucial to ecosystem productivity
Brown University scientists Osvaldo Sala and Pedro Flombaum conducted their studies of the effect of plant species diversity on ecosystem productivity in the Patagonian steppe, a semiarid grassland located on the east side of the Andes Mountains in Argentina. Credit: Courtesy of Osvaldo Sala, Brown University

In the first experiment involving a natural environment, scientists at Brown University have shown that richer plant diversity significantly enhances an ecosystem's productivity. The finding underscores the benefits of biodiversity, such as capturing carbon dioxide, a main contributor to global warming.

Osvaldo Sala, director of the Environmental Change Initiative and the Sloan Lindeman Professor of Biology at Brown, and Pedro Flombaum, a postdoctoral research associate in the Department of Ecology and Evolutionary Biology at Brown, said the results confirmed tests charting how biodiversity affects aboveground plant productivity in artificial ecosystems. Aboveground plant productivity (ANPP) is the amount of biomass, or organic material, produced by plant growth.

But the Brown team also learned that the correlation between plant species richness - the number of plant species in a unit of area - and ANPP in a natural ecosystem was greater than had been expected. What that means, the researchers wrote in a paper published online this week in the Proceedings of the National Academy of Sciences, is that the greater the number of plant species, the more productive the ecosystem.

Conversely, species loss has a decidedly negative impact on ecosystems. This is especially true in light of the role ecosystems play in capturing the global warming gas carbon dioxide: The fewer the plant species in a given natural environment, the less carbon dioxide they capture.

"It's a double whammy," Sala explained. "We not only are disturbing our planet by putting more carbon into the atmosphere, but we're reducing the ability of ecosystems to capture and store it."

Sala and Flombaum conducted their experiments in the Patagonian steppe, a semiarid grassland located on the east side of the Andes Mountains in Argentina. They marked 90 plots, each containing three species of native grasses and three species of native shrubs. The team then removed a certain number of species from the plots and measured each revised plot's productivity.

"The water is the same, the nitrogen is the same, the sunlight is the same," Sala said. "What is different is the diversity of the plants."

What the researchers also learned in their experiments, which ran from 2002 to this year, is that plant productivity in a flourishing ecosystem is enhanced because each species assumes a specific niche. Ecologists call this "niche complementarity." The plants use the resources available to the whole system harmoniously, such as extending their roots at different depths in the soil, using different forms of nitrogen, and staggering when they photosynthesize.

"We are deeper into understanding the mechanisms of an ecosystem's productivity," Sala said.

Source: Brown University

Explore further: Gimmicks and technology: California learns to save water

Related Stories

Insect decoys could protect ash trees

19 hours ago

Emerald ash borers have no trouble reproducing themselves as they have now spread through half the United States, but duplicating effective emerald ash borer decoys is not quite as easy. Now, engineers have ...

Fuel and chemicals from steel plant exhaust gases

Jul 01, 2015

Carbon monoxide-rich exhaust gases from steel plants are only being reclaimed to a minor extent as power or heat. Fraunhofer researchers have developed a new recycling process for this materially unused carbon resource: They ...

Restored streams take 25 years or longer to recover

Jun 30, 2015

New research has found that the number of plant species growing just next to restored streams can take up to 25 years to increase above those channelized during the timber floating era. This is according ...

Researchers discover how petunias know when to smell good

Jun 29, 2015

Good timing is a matter of skill. You would certainly dress up for an afternoon business meeting, but not an evening session of binge-watching Netflix. If you were just a few hours off in your wardrobe timing, ...

Recommended for you

Gimmicks and technology: California learns to save water

23 hours ago

Billboards and TV commercials, living room visits, guess-your-water-use booths, and awards for water stinginess—a wealthy swath of Orange County that once had one of the worst records for water conservation ...

Cities, regions call for 'robust' world climate pact

23 hours ago

Thousands of cities, provinces and states from around the world urged national governments on Thursday to deliver a "robust, binding, equitable and universal" planet-saving climate pact in December.

Will climate change put mussels off the menu?

Jul 03, 2015

Climate change models predict that sea temperatures will rise significantly, including in the tropics. In these areas, rainfall is also predicted to increase, reducing the salt concentration of the surface ...

As nations dither, cities pick up climate slack

Jul 02, 2015

Their national governments hamstrung by domestic politics, stretched budgets and diplomatic inertia, many cities and provinces have taken a leading role—driven by necessity—in efforts to arrest galloping ...

User comments : 0

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.