Extreme events as ecosystems drivers: ecological consequences of anomalous Southern Hemisphere weather patterns during the 2001/02 austral spring-summer

• Main Authors: Bergstrom, DM, Woehler, EJ, Klekociuk, AR, Pook, MJ, Massom, RA
• Format: Article in Journal/Newspaper
• Language: English
• Published: China Science Press 2018
• Subjects: extreme atmospheric events; Southern Hemisphere; ecological impacts; Antarctica; atmospheric pressure anomalies; ecosystem processes and drivers; tipping points; trophic cascades; regime shifts; Antarctic; Austral; East Antarctica; The Antarctic; Advances in Polar Science; Antarc*; Ice Shelf; Polar Science; Snow Petrel
• Online Access: https://eprints.utas.edu.au/39388/; https://eprints.utas.edu.au/39388/2/129146%20-%20Extreme%20events%20as%20ecosystems%20drivers,%20ecological%20consequences%20of%20anomalous.pdf

The frequency and severity of extreme events associated with global change are both forecast to increase with aconcomitant increase expected in perturbations and disruptions of fundamental processes at ecosystem, community and populationscales, with potentially catastrophic consequences. Extreme events should thus be viewed as ecosystem drivers, rather than as shortterm deviations from a perceived ‘norm’. To illustrate this, we examined the impacts associated with the extraordinary weatherpattern of the austral spring/summer of 2001/2002, and find that patterns of ocean-atmosphere interactions appear linked to a suite ofextreme events in Antarctica and more widely across the Southern Hemisphere. In the Antarctic, the extreme events appear related toparticular ecological impacts, including the substantial reduction in breeding success of Adélie penguins at sites in the AntarcticPeninsula as well as for Adélie penguin and snow petrel colonies in East Antarctica, and the creation of new benthic habitatsassociated with the disintegration of the Larsen B Ice Shelf. Other major impacts occurred in marine and terrestrial ecosystems attemperate and tropical latitudes. The suite of impacts demonstrates that ecological consequences of extreme events are manifested atfundamental levels in ecosystem processes and produce long-term, persistent effects relative to the short-term durations of theevents. Changes in the rates of primary productivity, species mortality, community structure and inter-specific interactions, andchanges in trophodynamics were observed as a consequence of the conditions during the 2001/2002 summer. Lasting potentialconsequences include reaching or exceeding tipping points, trophic cascades and regime shifts.