. | . |
Increased water availability may release more nutrients into soil in Antarctica by Staff Writers Hanover NH (SPX) Mar 15, 2017
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. The findings indicate that in the McMurdo Dry Valleys, as for many other regions, the two forms of phosphorus, labile and mineral phosphorus, are not related. Even though rock type may be used to help predict the amount of mineral phosphorus in soils, it does not predict how much phosphorus is available to organisms. Instead, the available phosphorus was found to be correlated with soil conductivity, soil texture and topography. The findings also revealed that landscape age across a gradient of approximately 20,000 to 1.5 million years was not a strong predictor of either form of phosphorus. "Mineral phosphorus, while not currently available to organisms, represents a large store of this essential nutrient that could become unlocked in the future," says lead author Ruth C. Heindel, a graduate student in earth sciences at Dartmouth. As global warming continues to impact the McMurdo Dry Valleys of Antarctica, with more meltwater streams and water tracks travelling across the landscape, more mineral phosphorus is likely to become available through rock weathering over centuries to millennia. Phosphorus loads are also likely to increase to Dry Valleys aquatic ecosystems, which are currently some of the most phosphorus-limited ecosystems on the planet. As more phosphorus becomes available, microscopic organisms, such as nematodes, tardigrades, rotifers, algae and cyanobacteria, may become more abundant in the McMurdo Dry Valleys.
Paris (AFP) March 1, 2017 The UN's World Meteorological Organization published the highest temperatures on record in three Antarctic zones Wednesday, setting a benchmark for studying how climate change is affecting this crucial region. Mapping Antarctica's extremes is essential for understanding weather patterns, and teasing out natural climate variability from human-induced climate change, the WMO said in a statemen ... read more Related Links Dartmouth College Beyond the Ice Age
|
|
The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us. |