Research conducted by a team of national and international researchers including Virginia Institute of Marine Science professor Emmett Duffett suggests that diverse plant communities are more integral in sustaining Earth’s ecosystems than are less diverse plant communities.
“The idea that declining diversity compromises the functioning of ecosystems was controversial for many years,” Duffy said in a press release. “This paper should be the final nail in the coffin of that controversy. It is the most rigorous and comprehensive analysis yet, and it clearly shows that extinction of plant species compromises the productivity that supports Earth’s ecosystems.”
According to 574 field and laboratory studies, which were conducted across five continents, plant communities with a variety of species were 1.5 times more productive than those with only one species. In addition, the generation of oxygen and the capturing of carbon dioxide were more than twice as fast in diverse communities.
“Low diversity means there is often no one else to take their place and the effects can ripple out through the community of animals, potentially up to fishery species,” Duffy said.
The research suggested a tipping point model to frame biodiversity loss in a community. Ecosystem production will show a dramatic drop at a certain point after a continuing period of species loss.
“[We are] in a position to calculate the number of species needed to support the variety of processes required to sustain life in real ecosystems,” the leader of the team of scientists, University of California at Santa Barbara professor of ecology, evolution and marine biology Bradley Cardinale, said. “And we do not mean ‘need’ in an ethical or an aesthetic way. We mean an actual concrete number of species required to sustain basic life-support processes.”
The small-scale experiments of the researchers only proved biodiversity loss to be more threatening to Earth’s ecosystems.
“Data are generally consistent with the idea that the strength of diversity effects are stronger in experiments that run longer, and in experiments performed at larger spatial scales.”
These findings, which apply to land as well as fresh and saltwater communities, were deemed by the researchers to be specially significant for the Chesapeake Bay.
Professor Duffett has recently received a grant from the National Science Foundation to continue biodiversity study in seagrass beds.