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One in three flowering plants may become extinct, study finds

A paper published today by a trio of American and British researchers in the journal Proceedings of the Royal Society B reveals that as many as a third of all flowering plants could be threatened with extinction. A great many of them could disappear before they are discovered and studied by scientists.

The lead author of the paper, Lucas Joppa, of Microsoft Research in Cambridge, UK, describes the main findings of the study. The other authors of the paper were David L. Roberts, of the Durrell Institute of Conservation and Ecology, School of Anthropology and Conservation, University of Kent, and Stuart L. Pimm, of the Nicholas School of the Environment, Duke University, North Carolina.


NGS stock photo by Michael Nichols

By Lucas Joppa

Faced with threats such as habitat loss and climate change, thousands of rare flowering plant species worldwide may become extinct before scientists can even discover them.

Scientists have estimated that, overall, there could be between 5 and 50 million species, but fewer than 2 million of these species have been discovered to date.


NGS stock photo by James P. Blair

Using novel methods, we were able to refine the estimate of total species for flowering plants, and calculate how many of those remain undiscovered.

Based on data from the online World Checklist of Selected Plant Families at the Royal Botanic Gardens, Kew, we calculated that there are between 10 and 20 percent more undiscovered flowering plant species than previously estimated. This finding has enormous conservation implications, as any as-yet-unknown species are likely to be overwhelmingly rare and threatened.

The new, more accurate estimate can be used to infer the proportion of all threatened species. If we take the number of species that are currently known to be threatened, and add to that those that are yet to be discovered, we can estimate that between 27 percent and 33 percent of all flowering plants will be threatened with extinction.

That percentage reflects the global impact of factors such as habitat loss. It may increase if you factor in other threats such as climate change.


NGS stock photo by James P. Blair

The timing couldn’t be more perfect. The year 2010 is the International Year of Biodiversity. We wrote the paper to help answer the obvious questions: How much biodiversity is out there, and how many species will we lose before they are even discovered?

This blog post was adapted from a news release issued by the authors.

Read the paper:

How many species of flowering plants are there?

By Lucas N. Joppa, David L. Roberts and Stuart L. Pimm

  • Lucas Joppa received his doctoral degree from Duke University in 2010. Stuart Pimm served as his faculty advisor. Pimm is a regular blogger for NatGeo News Watch.


NGS stock photo by Jodi Cobb

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