The Year of Melt: Two LTER Antarctic Sites Compare Impacts of Warm Weather

In 2001-2002, warm weather and strong winds descended on Antarctica, producing a single season of unusual and intense melting. For researchers at the two Long Term Ecological Research (LTER) sites on the continent, the anomaly provided a natural experiment in how these ecosystems will respond to climate change. Today, the LTER Network Communications Office (NCO), operated by NCEAS, announced the publication of four papers in a special section of October’s BioScience, all of which address the ecosystem responses observed at the sites in the months – and years – since that warm season.

For over 20 years, the Palmer and McMurdo Dry Valleys LTERs have conducted research and continuous monitoring in two vastly different Antarctic ecosystems. The Palmer LTER site focuses on a coastal ecosystem on the West Antarctic Peninsula, while the McMurdo Dry Valleys LTER site sits in a polar desert, one of the driest areas on Earth.

“With long-term studies already in place, we were able to observe the effects on so many different levels.”

                            - Hugh Ducklow, Palmer LTER Lead PI

In response to the warm Spring, the Palmer site saw a nutrient-rich release of fresh meltwater, inducing a population boom in krill and providing a rich food source for penguins, whales, seals, and fish – all of which proved to be relatively short-term, impermanent responses. In contrast, observations at the McMurdo Dry Valleys demonstrated how one season of uncharacteristic warming could trigger prolonged feedbacks. With thinning lake ice and newly flowing streams, researchers predict that resulting increased sunlight penetration and dissolved organic carbon inputs could potentially alter the structure of microbial communities in the Antarctic lakes.

The long-term data collected at Palmer and McMurdo LTERs have enabled scientists to track the cascading effects of climate variability through both marine and terrestrial Antarctic ecosystems and given them the opportunity to explore how these ecosystems will respond to future climate events.

Special Section of October’s BioScience

Unravelling Ecosystem Responses to Climate Change on the Antarctic Continent Through Long Term Ecological Research
J. Priscu
BioScience, 13 October 2016, DOI: http://doi:10.1093/biosci/biw131

The Impact of a Large-scale Climate Event on Antarctic Ecosystem Processes
A. Fountain, G. Saba, B. Adams, P. Doran, W. Fraser, M. Gooseff, M. Obryk, J. Priscu, S. Stammerjohn, and R. Virginia.
BioScience, 13 October 2016, DOI: http://doi:10.1093/biosci/biw110

Responses of Antarctic Marine and Freshwater Ecosystems to Changing Ice Conditions
M. Obryk, P. Doran, A. Friedlaender, M. Gooseff, W. Li, R. Morgan-Kiss, J. Priscu, O. Schofield, S. Stammerjohn, D. Steinberg, and H. Ducklow.
BioScience, 13 October 2016, DOI: http://doi:10.1093/biosci/biw109

Microbial Community Dynamics in Two Polar Extremes: The Lakes of the McMurdo Dry Valleys and the West Antarctic Peninsula Marine Ecosystem
J. Bowman, T. Vick-Majors, R. Morgan-Kiss, C. Takacs-Vesbach, H. Ducklow, and J. Priscu.
BioScience, 13 October 2016, DOI: http://doi:10.1093/biosci/biw103


LTER NCO Press Release


Photo Credit: Hassan Basagic/McMurdo LTER via CC by-SA 4.0


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Posted on October 13, 2016