DIVERSE ecosystems are far more productive than monocultures, according to a
new study. In a seven-year experiment, David Tilman, an ecologist at the
University of Minnesota in St Paul, found that plots of grassland planted with
16 species produced 2.7 times as much biomass as plots planted with a single
species.
Tilman’s work has been controversial. In 1996 he pointed to the link between
diversity and productivity. But critics dismissed the results from these earlier
experiments, saying that they could have been caused by faulty experimental
design. They argued that the apparent productivity of the diverse plots could be
because…
