Data from: Mass ratio effects underlie ecosystem responses to environmental change

1.    Random species loss has been shown experimentally
to reduce ecosystem function, sometimes more than other anthropogenic
environmental changes. Yet, controversy surrounds the importance of this
finding for natural systems where species loss is non-random. 
2.      We compiled data from 16 multi-year
experiments located at a single site in native tallgrass prairie. These
experiments included responses to 11 anthropogenic environmental changes,
as well as non-random biodiversity loss - either the removal of
uncommon/rare plant species or the most common (dominant)
species.  3.      As predicted by the
mass ratio hypothesis, loss of a dominant species had large impacts on
productivity that were comparable to other anthropogenic drivers. In
contrast, the loss of uncommon/rare species had small effects on
productivity despite having the largest effects on species
richness.  4.      The anthropogenic
drivers that had the largest effects on productivity – nitrogen,
irrigation, and fire – experienced not only loss of species but also
significant changes in the abundance and identity of dominant species.
5.      Synthesis. These results suggest that
mass ratio effects rather than species loss per se is an important
determinant of ecosystem function with environmental change.