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: New report highlights 'significant and increasing' risks from extreme weather

add to favorites email to friend print save as pdf

Related Stories

Pop music heritage contributes to the formation of identity

11 minutes ago

The musical rebels of the past are today's museum pieces. Pop music is increasingly penetrating heritage institutions such as museums and archives. That is apparent from the PhD research of Arno van der Hoeven. On Thursday ...

Male sex organ distinguishes 30 millipede species

13 minutes ago

The unique shapes of male sex organs have helped describe thirty new millipede species from the Great Western Woodlands in the Goldfields, the largest area of relatively undisturbed Mediterranean climate ...

Orion on track at T MINUS 1 Week to first blastoff

28 minutes ago

At T MINUS 1 Week on this Thanksgiving Holiday, all launch processing events remain on track for the first blast off of NASA's new Orion crew vehicle on Dec. 4, 2014 which marks the first step on the long ...

Helping older employees stay in their jobs

31 minutes ago

Factors that can hinder older employees from continuing to work include workload, a poor memory and the pensionable age-effect. The Job-Exposure Matrix is a newly developed instrument that provides an easy way to chart the ...

Recommended for you

Gold rush an ecological disaster for Peruvian Amazon

2 hours ago

A lush expanse of Amazon rainforest known as the "Mother of God" is steadily being destroyed in Peru, with the jungle giving way to mercury-filled tailing ponds used to extract the gold hidden underground.

Australia out of step with new climate momentum

4 hours ago

Australian Prime Minister Tony Abbott, who rose to power in large part by opposing a tax on greenhouse gas emissions, is finding his country isolated like never before on climate change as the U.S., China ...

Education is key to climate adaptation

19 hours ago

Given that some climate change is already unavoidable—as just confirmed by the new IPCC report—investing in empowerment through universal education should be an essential element in climate change adaptation ...

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.