Biodiversity theory debunked

According to biology text books, the relationship between species richness and productivity is hump-shaped. Biodiversity first rises as resources increase, until the area becomes so fertile that larger, fast-growing species begin to crowd out the smaller slow-growing plants, and biodiversity then declines.

But work published in Science debunks this theory. Peter Adler, a plant ecologist at Utah State University in Logan, together with an international network of collaborators show that, on the small scale at least, there is no consistent relationship between biodiversity and productivity, although the link may still hold on regional or global scales.

“This relationship does not deserve its place as one of these text-book patterns that students are introduced to,” Adler told Nature.

Disproving the relationship at small scales is important, he says, “because this is the scale at which we test our theories of plant species interactions.”