The finding raises concern that more may have to be done to protect the Earth's most biologically rich areas.
The meta-analysis was sponsored by the National Center for Ecological Analysis and Synthesis at the University of California, Santa Barbara and was funded by the National Science Foundation. The article, "Pollination Decays in Biodiversity Hotspots," reporting the results, is published in the January 17 issue of the Proceedings of the National Academy of Sciences and is available online at the academy's website at www.pnas.org.
The analysis shows that ecosystems with the greatest number of species, including the jungles of South America and Southeast Asia and the rich shrubland of South Africa, have bigger deficits in pollination compared to the less-diverse ecosystems of North America, Europe and Australia.
"This is truly a synthetic work," said Susan Mazer, co-author of the article and a professor of biology at UC Santa Barbara. "Our detection of global patterns required the simultaneous analysis of many studies conducted independently by plant ecologists all over the world." The meta-study analyzes 482 field experiments on 241 flowering plant species conducted since 1981. The study took several years to complete and all continents except Antarctica are represented.
"This analysis can tell us things about ecological processes at the global scale that individual studies are not designed to tell us," she said, noting that the synthesis could not have been done 25 years ago because few careful field studies of this type had yet been conducted. Each individual study represented in the meta-study is highly labor-intensive and species-specific.