As climate change continues to impact the Antarctic, glacier melt and permafrost thaw are likely to make more liquid water available to soil and aquatic ecosystems in the McMurdo Dry Valleys, potentially providing a more nutrient-rich environment for life, according to a Dartmouth study recently published in Antarctic Science. (A pdf of the study is available upon request).
With an average annual air temperature of -2.2 F and an average precipitation of 3-50 mm per year, the McMurdo Dry Valleys of Antarctica are dominated by dry soils underlain by permafrost. The Dry Valleys ecosystem is severely limited by liquid water and nutrients, resulting in limited organic matter. One such limited nutrient is phosphorus, an element that is essential to all living organisms. Understanding the spatial distribution of phosphorus in the soil is crucial to identifying where life could become more abundant in the future.
Dartmouth scientists examined the variability of soil phosphorus in the McMurdo Dry Valleys by evaluating two forms of phosphorus in surface soil samples: labile phosphorus, which is immediately available to organisms, and mineral phosphorus, which needs to be broken down by weathering before organisms can use it. The researchers analyzed how parent material, landscape age, soil chemistry and texture, and topography affect the two forms of phosphorus.
Read more at Dartmouth College
Figure: Map of study locations. a. Location of study area on the Antarctic continent. b. Location of places mentioned in the study: Ross Island (1), McMurdo Sound (2), Taylor Valley (3; box shows location of c.), Garwood Valley (4) and Miers Valley (5). c. Inset of Taylor Valley showing sampling locations: Hjorth Hill (i), New Harbor (ii), Fryxell Basin (iii), upland ponds (iv), Bonney Basin (v). Satellite images provided by the Polar Geospatial Center. Graphic by Ruth Heindel.
Satellite images provided by the Polar Geospatial Center. Graphic by Ruth Heindel.
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