Simultaneous exposure to multiple stressors potentially complicates
enormously the challenge of predicting ecological responses to global
environmental change. Here, we show that, though the contributions of
individual species and functional groups to ecosystem stability may vary
under different disturbance types, their contributions to stability
under combined stressors can nonetheless frequently be predicted from
their contributions under the individual disturbances acting in
isolation. By disturbing natural rocky shore communities experimentally
with nutrients and sediments and simultaneously simulating extinction of
predatory whelks and grazing consumers both separately and in
combination, we found that trophic position does not, however, appear to
be a useful general predictor of species contributions to stability. We
conclude that quantifying contributions of key species and functional
groups to stability across a range of environmental contexts may provide
a pathway towards predicting the multifaceted responses of ecosystems to
distinct combinations of stressors acting simultaneously.