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| Content Provider | Springer Nature Link |
|---|---|
| Author | Barrett, John E. Virginia, Ross A. Wall, Diana H. |
| Copyright Year | 2002 |
| Abstract | Previous descriptions of soils in the McMurdo Dry Valleys, Antarctica, have focused on the dominance of abiotic controls rather than on nutrient cycling. Although free-living N2-fixing and nitrifying microorganisms have been isolated in Antarctic soils, little is known about in situ nitrogen (N) cycling. We measured KCl-extractable NH4 + and NO3 –, as well as anion resin exchangeable NO3 –, across sediment–soil transects and in two positions on a hill slope in Taylor Valley, Antarctica. These landscapes provide gradients of soil moisture, salinity, and texture that influence invertebrate communities and organic matter dynamics. Assuming an N cycle dominated by abiotic inputs, we hypothesized that inorganic N content would be predominantly comprised of NO3 – and most strongly correlated to soil salinity, while NO3 – flux (estimated by resin adsorption) would be most influenced by soil water content, salinity, and total soil NO3 – concentrations. Our results were inconsistent with a physically dominated N cycle. In contrast to previous studies of Dry Valley soils, we found that NH4 + made up a large proportion of inorganic N. Total KCl-extractable N was correlated most strongly with total soil N and soil moisture. The most saline soils in the swale of a hill slope had the highest concentrations of NO3 –, but we found no overall correlation between soil salinity and resin-exchangeable NO3 – or KCl-extractable N. Resin-extractable NO3 – was most strongly correlated with total soil N, soil water content, and KCl-extractable NH4 +, suggesting that accumulation of NO3 – in resins was influenced by the mineralization of organic matter and not strictly by ionic migration, as an abiotic-based model may have predicted. We conclude that biological N cycling is significant in some Dry Valley soils and that the dominance of biological vs physical influences over N cycling is controlled in part by the availability of soil moisture and organic matter. |
| Starting Page | 289 |
| Ending Page | 299 |
| Page Count | 11 |
| File Format | |
| ISSN | 14329840 |
| Journal | Ecosystems |
| Volume Number | 5 |
| Issue Number | 3 |
| Language | English |
| Publisher | Springer-Verlag |
| Publisher Date | 2002-03-01 |
| Publisher Place | Berlin, Heidelberg |
| Access Restriction | One Nation One Subscription (ONOS) |
| Content Type | Text |
| Resource Type | Article |
| Subject | Ecology Environmental Chemistry Ecology, Evolution, Behavior and Systematics |
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