Local weather fluctuations have long been known to influence ecosystem changes, but Stenseth et al (2002) examine how large-scale interannual fluctuations in climate set in place sequences of changes in components of ecosystems. They use El Niño/La Niña and the positive/negative phases of the North Atlantic Oscillation as examples of such drivers of ecosystem change. Impacts of climate may come through direct physiological effects, or indirectly through the ecosystem such as predator-prey relationships. They suggest five factors be considered:
1) delayed effects of climate fluctuations are important for both marine
and terrestrial systems
2) climate has differential effects on sexes and age-classes
3) climate change may lead to higher frequency of extreme events, which have high impact on ecosystems
4) climate variability may impact a particular ecosystem component directly or indirectly through its interaction with other ecosystem components
5) ecosystem characteristics may determine whether a particular climate change has a significant impact.
A whole new are of study is emerging through recognitions of these coupled climate/ecosystem interactions.
Stenseth, N. C., A. Mysterud, G. Ottersen, J. W. Hurrell, K.-S. Chan, and M. Lima, 2002: Ecological effects of climate fluctuations. Science, 297, 1292-1296.