"We move species around," Gotelli says. "There is a huge ant diversity in Florida, and about 30 percent of the ant species are non-natives. They have been accidentally introduced, mostly from the Old World tropics, and they are now a part of the local assemblage. So you can have increased diversity in local communities because of global homogenization."
And sampling issues may conceal important realities: some species may have become so rare think white rhinos that they're highly unlikely to be found in a general species survey and so don't show in the initial results nor disappear in later ones.
Range shifts associated with climate change could be at work, too, quickly pushing species into new terrain. On May 6, the White House released its National Climate Assessment noting that, as a result of human-caused warming, "species, including many iconic species, may disappear from regions where they have been prevalent or become extinct, altering some regions so much that their mix of plant and animal life will become almost unrecognizable."
This study in Science,"Assemblage Time Series Reveal Biodiversity Change Systematic Loss," published on April 18, underlines this emerging reality, giving it a new and worrisome precision and leading Nick Gotelli and his co-authors to conclude that there "is need to expand the focus of research and planning from biodiversity loss to biodiversity change."
|Contact: Joshua Brown|
University of Vermont