Ecology

he Transantarctic Mountains and after the LGM. To do this, the team is inroads into this field of knowledge. For terrestrial environments unsuitable for extend 3,000 miles across using advanced surface dating techniques example, they have shown the importance most organisms. Antarctica and are among the and ‘omics’ tools to reveal the response of of liquid water and soil leaching resulting Linking climate largest mountain chains in the soil ecosystems to altering climates, and from glacial melt for maintaining suitable How invertebrates survived during various world. This expanse is home to discover how soils might have hosted life habitats for microscopic organisms such glacial events of the LGM is a prime question large outlet glaciers such as the Beardmore when nearly all of the currently ice-free as nematodes. raised by the research team. While they can Tand Shackleton Glaciers. Today, Antarctica’s areas of Antarctica were completely observe that nematodes generally survive change to ice sheets are known to be receding, as covered by ice. SURVIVORS IN THE SOIL by going into a state of dormancy – named an aftermath of the Last Glacial Maximum Soils are vital for the functioning of “anhydrobiosis” – during dry and cold (LGM) around 21,000 years ago. The LGM THE RESPONSE OF SOIL ECOSYSTEMS ecosystems, running processes such as extremes like the LGM, it is assumed that was the most recent period when the AFTER GLACIAL RECESSION greenhouse gas absorption and organic invertebrates must have found places of refuge ecosystem assembly Earth’s ice sheets were at their greatest The ice-free areas of Antarctica provide matter degradation. Soil ecosystems during the ice ages. Non-glaciated soil settings extension, occurring after a period of a patchwork of relatively simple, yet respond to climate-driven disturbances existed at high elevations in the Transantarctic cooling during the Pleistocene epoch. habitable soil ecosystems, which makes such as altering temperatures and Mountains during the LGM; the research it an ideal model for scientific study. The atmospheric compositions, which can occur team suspected that refuges may be present and functioning How endemic organisms survived during team has been investigating the little over thousands to millions of years. In in these high-elevation, ice-free regions. these glacial events has been a previously understood question of how ecosystems shorter time-scales they may be affected However, in a study of the ice free areas in the As part of a collaborative project, Professor Byron Adams neglected question. Even in this region’s in this area have changed in response by physical events such as being wetted, Beardmore Glacier region, they identified high (Brigham Young University) and colleagues Diana Wall (Colorado apparent desolation, there are networks of to glacial recession by considering the induced by glacial melt. As a result of concentrations of nitrate salts in the high- life unfolding within the soils. Antarctica’s biotic and abiotic factors at play. Climate, warming since the LGM, receding glaciers elevation soils. Despite these exposed regions State University), (University of Colorado), Noah Fierer Berry remote landscapes are of great interest species interactions and habitat suitability left behind varied patches of soils across being free of ice, the high salt content in the Lyons (The Ohio State University) in the USA, and Ian Hogg (Polar to scientists, with natural settings that are may drive the origins and structures Antarctica, holding unique geochemistry, soils would have been unsuitable habitats for Knowledge Canada) are investigating settings in the Transantarctic largely unspoiled by human activity. Now, of ecological communities, but little is and ecological communities. In addition invertebrates. The scientists are now curious Mountains to understand how land-based ecosystems have a multi-collaborative project, funded by known about how ecosystems respond to to the cold, the presence of salt and the as to whether appropriate habitats can be responded to climate change. The team is seeking to find out how the National Science Foundation (USA), is climate-driven environmental changes. It low carbon content of the soils adds to found in other high-altitude regions of the investigating the environmental factors that is supposed that glacial retreat after the the harshness of this setting. Soluble Antarctic or whether there are alternative communities of soil organisms changed and re-assembled as they have hosted life here, and how ecosystems LGM left behind new habitats for life forms salts have a weathering effect on soils, ways in which ecosystems functioned through emerged from the last ice age. reacted to glacial events before, during, to re-colonise and the team has made but in high concentrations can make the Pleistocene.

The ice-free areas of Antarctica provide a patchwork of relatively simple, yet habitable soil ecosystems

66 Ecology

Detail

RESEARCH OBJECTIVES The team’s work focuses on the Is the use of DNA sequencing tools and mitigate the impact of rapid climate maps, aerial photographs and interaction between climate and a novel method for investigating soil change on natural and managed satellite imagery (provided by the ecosystems. In particular, they ecosystems in the Antarctic? ecosystems, such as in agriculture and Polar Geospatial Center), very few are interested in working out how DNA sequencing sees frequent use in forestry. people, if any, have actually been on phylogenetic history, functional diversity, Antarctic ecosystems to characterise the ground at the locations where and abiotic environmental components biodiversity. However, our work is What features and patterns are we need to work and so we’ll need influence ecosystem-level responses to novel in that we are also interested in you expecting to find at Shackleton to be really flexible in terms of how climate change. characterising specific genes that confer Glacier, and how may they differ to the and where we set up our sampling important ecological functions of the Beardmore Glacier? transects. FUNDING organisms that possess them. In order Due to logistic constraints our previous NSF to do this we are not only sequencing work at the Beardmore Glacier allowed only How do you think Antarctica’s environmental DNA so thoroughly that a few hours on the ground at three different environment and ecosystems will CONTACT we can reconstruct the entire genome features. This year the National Science alter in the near future? Byron Adams, PhD of every species in each sample, but by Foundation is providing us with helicopter Global and regional climate models 4102 Life Sciences Building sequencing the transcriptomes of each support to nine different areas in the predict amplified warming throughout Department of Biology organism in the sample we’ll get a very region, allowing us to collect and analyse a the Transantarctic Mountains. While Brigham Young University precise picture of the functional role each greater number of samples across a larger we predict increased warming to Provo, UT 84602 species plays in the ecosystem as well. spatial scale, and from areas for which result in increased glacial meltwater, USA we can obtain accurate surface exposure resulting in warmer, wetter soils Can your research insights and dates. Thus, we predict that we can recover and hospitable habitat, some of our E: [email protected] methods be applied to other regions consistent patterns of ecosystem assembly previous experimental work shows T: + 1 801 423 7889 of the world? and functioning along a spatial and that warmed soils can also become W: https://adamslab.byu.edu/ We hope that by figuring out how these temporal gradient since the LGM. drier, resulting in poorer habitat and relatively simple soil communities have decreased ecosystem functioning. It responded to gradual global warming What do you think will be the main will be important to monitor these Above: Map of the Shackleton Glacier; red stars indicate features to be studied. Below: Schematic representation since the Pleistocene, our work can challenges faced by your team at regions of Antarctica in the coming of present and LGM surface profiles of Shackleton Glacier. LGM reconstructions are based on modelled and inform predictive models and ongoing Shackleton Glacier? years. measured mean upper limits of the East Antarctic Ice Sheet. All features have terrestrial ecosystems that were most research that aims to better understand Although we have access to excellent likely exposed during the Pleistocene except for Mt. Nilsen, Cathedral Peaks, and the vast majority of Mt. Heekin. Adapted from "Central Transantarctic Mountains: McMurdo Dry Valleys to Wisconsin Range" by Brad Herried, Polar Geospatial Center, Reference ID: ANT REF-MS2006-001.

THE NEXT STEP – AN EXCURSION TO help address their question of how living relationships among all the life forms in the SHACKLETON GLACIER organisms respond to glacial recession, and ecosystem. These genealogical histories are In an upcoming excursion to the Shackleton perhaps inform models of how they may represented as phylogenetic trees, much Glacier region of the Transantarctic do so in the future. One hypothesis is that like family trees. These data can then be Mountains, the team will be digging into complex interactions between organisms associated with features of the corresponding these questions on how climate-driven would have increased as the ice receded. By habitat, and compared with historic events such as the LGM have impacted connecting physical factors with biodiversity sequences of events over deep time. ecological communities in the soil. Here, and ecosystem data, the team suspect that they will collect field samples at various patterns of community structure may emerge TIME IS OF THE ESSENCE Byron J. Adams (Lead PI) Diana H. Wall W. Berry Lyons Ian D. Hogg Noah Fierer Department of Biology, elevations above and below the previous at various scales. To define these frameworks, Prof Adams and the team are working to Department of School of Earth Sciences Canadian High Arctic Department of Ecology Evolutionary Ecology Biology and School of and the Byrd Polar Research Station, and Evolutionary Biology, maximum extent of the glacier. The largely they will be observing communities in real- unravel the complicated patchwork of soil Laboratories, and Monte Global Environmental and Climate Research Polar Knowledge and Cooperative untouched, ‘ice-free’ features of this area will time, using technological advances in DNA ecosystems left behind by warming events L. Bean Life Science Sustainability, Colorado Center, The Ohio State Canada, Cambridge Institute for Research in provide them with an ideal representation of sequencing and bioinformatics. The sequence over Antarctica since the LGM. The processes Museum, Brigham Young State University, University, Columbus, Bay, Nunavut, Environmental Sciences, how terrestrial ecosystems have responded analyses of genes can be used to recover that shaped the way soils have assembled University, Provo, Utah, Fort Collins, Colorado, Ohio, USA Canada. University of Colorado, to glacial recession in the past. This will and depict the evolutionary histories and since this time, and the responses of biotic USA USA Boulder, Colorado, USA communities to climate change are key considerations. Although the team are clear that ecosystem changes have been relatively Christopher B. Gardner Marci M. Shaver-Adams Melisa Diaz These simple terrestrial ecosystems stable here since the LGM, they suspect School of Earth Sciences Department of Biology, School of Earth Sciences that much will soon change with the onset and Byrd Polar and Brigham Young University, and Byrd Polar and Climate allow soil communities to be surveyed in of global warming and the ameliorisation of Climate Research Center, Provo, Utah, USA Research Center, The Ohio The Ohio State University, State University, Columbus, the ozone hole. Their upcoming research at unprecedented detail, to an extent not Columbus, Ohio, USA Ohio, USA Shackleton Glacier is therefore all the more feasible in more species-rich ecosystems urgent and important.

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