Inland diatoms from the McMurdo Dry Valleys and James Ross Island, Antarctica

Diatom taxa present in the inland streams and lakes of the McMurdo Dry Valleys and James Ross Island, Antarctica, are presented in this paper. A total of nine taxa are illustrated, with descriptions of four new species ( Luticola austroatlantica sp. nov., Luticola dolia sp. nov., Luticola laeta sp. nov., Muelleria supra sp. nov.). In the perennially ice-covered lakes of the McMurdo Dry Valleys, diatoms are confined to benthic mats within the photic zone. In streams, diatoms are attached to benthic surfaces and within the microbial mat matrix. One species, L. austroatlantica, is found on James Ross Island, of the southern Atlantic archipelago, and the McMurdo Dry Valleys. The McMurdo Dry Valley populations are at the lower range of the size spectrum for the species. Streams flow for 6–10 weeks during the austral summer, when temperatures and solar radiation allow glacial ice to melt. The diatom flora of the region is characterized by species assemblages favored under harsh conditions, with naviculoid taxa as the dominant group and several major diatom groups conspicuously absent.

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Austral summer foehn winds over the McMurdo dry valleys of Antarctica from Polar WRF

Quarterly Journal of the Royal Meteorological Society ◽

10.1002/qj.2278 ◽

2014 ◽

Vol 140 (683) ◽

pp. 1825-1837 ◽

Cited By ~ 15

Author(s):

Daniel F. Steinhoff ◽

David H. Bromwich ◽

Johanna C. Speirs ◽

Hamish A. McGowan ◽

Andrew J. Monaghan

Keyword(s):

Austral Summer ◽

Mcmurdo Dry Valleys ◽

Dry Valleys

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High-resolution elevation mapping of the McMurdo Dry Valleys, Antarctica, and surrounding regions

Earth System Science Data ◽

10.5194/essd-9-435-2017 ◽

2017 ◽

Vol 9 (2) ◽

pp. 435-443 ◽

Cited By ~ 11

Author(s):

Andrew G. Fountain ◽

Juan C. Fernandez-Diaz ◽

Maciej Obryk ◽

Joseph Levy ◽

Michael Gooseff ◽

...

Keyword(s):

Ad Hoc ◽

Austral Summer ◽

Mcmurdo Dry Valleys ◽

Dry Valleys ◽

The Past ◽

Detailed Surface ◽

Mcmurdo Station ◽

Coastal Margin ◽

Lidar Return ◽

Combined Data

Abstract. We present detailed surface elevation measurements for the McMurdo Dry Valleys, Antarctica derived from aerial lidar surveys flown in the austral summer of 2014–2015 as part of an effort to understand geomorphic changes over the past decade. Lidar return density varied from 2 to > 10 returns m−2 with an average of about 5 returns m−2. Vertical and horizontal accuracies are estimated to be 7 and 3 cm, respectively. In addition to our intended targets, other ad hoc regions were also surveyed including the Pegasus flight facility and two regions on Ross Island, McMurdo Station, Scott Base (and surroundings), and the coastal margin between Cape Royds and Cape Evans. These data are included in this report and data release. The combined data are freely available at https://doi.org/10.5069/G9D50JX3.

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The Mcmurdo Dry Valleys Long‐Term Ecological Rsearch Program: New understanding of the biogeochemistry of the Dry Valley Lakes: A review1

Polar Geography ◽

10.1080/10889370109377713 ◽

2001 ◽

Vol 25 (3) ◽

pp. 202-217 ◽

Cited By ~ 13

Author(s):

W. Berry Lyons ◽

Kathleen A. Welch ◽

John C. Priscu ◽

Johanna Labourn‐Parry ◽

Daryl Moorhead ◽

...

Keyword(s):

Mcmurdo Dry Valleys ◽

Dry Valleys ◽

Dry Valley

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Extreme streams: flow intermittency as a control on diatom communities in meltwater streams in the McMurdo Dry Valleys, Antarctica1This article is derived from a special session entitled “A New Hydrology: Inflow Effects on Ecosystem Form and Functioning” that took place at the February 2011 ASLO Aquatic Sciences conference in San Juan, Puerto Rico.

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f2012-022 ◽

2012 ◽

Vol 69 (8) ◽

pp. 1405-1419 ◽

Cited By ~ 20

Author(s):

Lee F. Stanish ◽

Tyler J. Kohler ◽

Rhea M.M. Esposito ◽

Breana L. Simmons ◽

Uffe N. Nielsen ◽

...

Keyword(s):

Community Composition ◽

Endemic Species ◽

Mcmurdo Dry Valleys ◽

Dry Valleys ◽

Intermittent Streams ◽

Diatom Community ◽

Diatom Communities ◽

Dry Valley ◽

Flow Intermittency ◽

Diatom Community Composition

In the McMurdo Dry Valleys of Antarctica, stream biota is limited by the brief availability of liquid water. The benthic microbial mats harbor diatoms that have adapted to hydrologic stresses, including numerous endemic species. We found a strong relationship between diatom community composition and flow intermittency in a data set including seven streams that spanned a gradient in flow intermittency. In particular, two genera represented by numerous endemic species in Dry Valley habitats, Hantzschia and Luticola , had high abundances in moderately and highly intermittent streams, respectively. The Shannon Index of diversity was greatest in streams with intermediate flow intermittency, with lower diversity in more stable streams resulting from lower evenness, and lower diversity in highly intermittent streams resulting from lower richness. These results indicate that multiple metrics of biodiversity may be useful in assessing the response of diatom communities to changing hydrologic regime. We propose that flow intermittency acts as a species filter that increases habitat heterogeneity in Dry Valley streams and may allow endemic species to persist. Future Antarctic warming may alter diatom community composition and habitats that act as refugia for desiccation-tolerant taxa.

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The aeolian flux of calcium, chloride and nitrate to the McMurdo Dry Valleys landscape: evidence from snow pit analysis

Antarctic Science ◽

10.1017/s095410200600054x ◽

2006 ◽

Vol 18 (4) ◽

pp. 497-505 ◽

Cited By ~ 51

Author(s):

Rebecca A. Witherow ◽

W. Berry Lyons ◽

Nancy A.N. Bertler ◽

Kathleen A. Welch ◽

Paul A. Mayewski ◽

...

Keyword(s):

Calcium Chloride ◽

Great Influence ◽

Strong Relationship ◽

Snow Accumulation ◽

Mcmurdo Dry Valleys ◽

Dry Valleys ◽

Dust Transport ◽

Atmospheric Flux ◽

Dry Valley ◽

Nitrogen Concentrations

We have determined the flux of calcium, chloride and nitrate to the McMurdo Dry Valleys region by analysing snow pits for their chemical composition and their snow accumulation using multiple records spanning up to 48 years. The fluxes demonstrate patterns related to elevation and proximity to the ocean. In general, there is a strong relationship between the nitrate flux and snow accumulation, indicating that precipitation rates may have a great influence over the nitrogen concentrations in the soils of the valleys. Aeolian dust transport plays an important role in the deposition of some elements (e.g. Ca2+) into the McMurdo Dry Valleys' soils. Because of the antiquity of some of the soil surfaces in the McMurdo Dry Valleys regions, the accumulated atmospheric flux of salts to the soils has important ecological consequences. Although precipitation may be an important mechanism of salt deposition to the McMurdo Dry Valley surfaces, it is poorly understood because of difficulties in measurement and high losses from sublimation.

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High-resolution elevation mapping of the McMurdo Dry Valleys, Antarctica and surrounding regions

10.5194/essd-2016-63 ◽

2017 ◽

Cited By ~ 2

Author(s):

Andrew G. Fountain ◽

Juan C. Fernandez-Diaz ◽

Joseph Levy ◽

Michael Gooseff ◽

David J. Van Horn ◽

...

Keyword(s):

Ad Hoc ◽

Austral Summer ◽

Mcmurdo Dry Valleys ◽

Dry Valleys ◽

The Past ◽

Detailed Surface ◽

Mcmurdo Station ◽

Coastal Margin ◽

Lidar Return ◽

Combined Data

Abstract. We present detailed surface elevation measurements for the McMurdo Dry Valleys, Antarctica derived from aerial lidar surveys flown in the austral summer of 2014–2015 as part of an effort to understand geomorphic changes over the past decade. Lidar return density varied from 2 to > 10 returns m−2 with an average of about 5 returns m−2. vertical and horizontal accuracies are estimated to be 7 cm and 3 cm, respectively. In addition to our intended targets, other ad hoc regions were also surveyed including the Pegasus flight facility and two regions on Ross Island, McMurdo Station, Scott Base (and surroundings), and the coastal margin between Cape Royds and Cape Evans. These data are included in this report and data release. The combined data is freely available at doi:10.5069/G9D50JX3.

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The seasonal evolution of albedo across glaciers and the surrounding landscape of the Taylor Valley, Antarctica

10.5194/tc-2019-146 ◽

2019 ◽

Cited By ~ 1

Author(s):

Anna Bergstrom ◽

Michael Gooseff ◽

Madeline Myers ◽

Peter T. Doran

Keyword(s):

Austral Summer ◽

Short Wave ◽

Desert Ecosystem ◽

Dry Valleys ◽

Seasonal Evolution ◽

Taylor Valley ◽

Incoming Radiation ◽

Dry Valley ◽

Summer Temperatures ◽

Surrounding Landscape

Abstract. The McMurdo Dry Valleys (MDVs) of Antarctica are a polar desert ecosystem consisting of alpine glaciers, ice-covered lakes, streams, and expanses of vegetation-free rocky soil. Because average summer temperatures are close to 0 °C, glacier melt dynamics in particular, but the Dry Valley ecosystem in general, are closely linked to the energy balance. A slight increase in incoming radiation or change in albedo can have large effects on the timing and volume of melt water. However, we have yet to fully characterize the seasonal evolution or spatial variability of albedo in the valleys. In this study, we aim to understand the drivers of landscape albedo change within and across seasons. To do so, we used a camera, gps, and short wave radiometer from a helicopter-based platform to fly transects 4–5 times a season along Taylor Valley over three seasons. We coupled these data with incoming radiation measured at 6 meteorological stations distributed along the valley to calculate the distribution of albedo across individual glaciers, lakes, and the soil surfaces. We hypothesized that albedo would decrease throughout the austral summer with ablation of snow patches and ice and increasing sediment exposure on the glacier and lake surfaces. However, small snow events (

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