Bee and Flowering-Plant Diversity Dropping

The diversity of bees and the plants they pollinate has declined in Britain and the Netherlands according to research published in the 21 July 2006 issue of the journal Science.

Jacobus Biesmeijer of the University of Leeds in the United Kingdom and his colleagues compiled thousands of records of where people have spotted bees, hoverflies and various pollinated plants over recent decades throughout the United Kingdom and the Netherlands.

The researchers found that the diversity of bee and pollinated-plant species have both decreased since 1980. The hoverflies didn't show such a clear pattern. The researchers think this may be because the flies can pollinate a wider variety of plants, whereas the bees are more selective. Further, plant species reliant on the declining pollinators have themselves declined relative to other plant species, Biesmeijer and colleagues report

Many agricultural crops and natural plant communities depend on pollination, often by wild populations of insects. Researchers and policy-makers have raised concerns about losing pollination “services,” but the evidence that such declines are underway has been scanty, according to the authors.

It's not clear whether the plants or the pollinator declined first, or whether they were both responding to some other factor, but the declines are clearly occurring in parallel, the authors say.

Kathy Wren

21 July 2006