Research Summary

Early Exploration and Diatom Biogeography

Ernest Shackleton’s Hut at Cape Royds is among the most famous historic sites on the Antarctic Continent. Recent years have seen Shackleton’s stature grow as the Antarctic explorer who led by example and “never lost a man,” largely at the expense of the reputation of Captain Scott who is often seen as having been somewhat aloof and distant from his men. The light, open-plan layout of the Cape Royd’s hut contrasts starkly with Captain Scott’s darker and more segregated hut at Cape Evans, and the design of the two huts might be seen as reflecting the respective leadership styles.

Telemetry and the monitoring program

Beginning the 2010-2011 season, we have installed a telemetry network that utilizes the Iridium satellite network and radios to connect 14 meteorological stations, 8 stream gages, and five lake monitoring stations to transfer data year round. Four hubs, often co-located at a monitoring site when topography allows, receive satellite phone calls originating in the US to open a connection, then sequence through as many as seventeen different data loggers via radio communications to harvest the latest data.

Climate and Resource Legacies in Taylor Valley: The Influence of Paleolake Washburn on Soil Biogeochemistry and Biodiversity

Climate driven variations in lake levels since the Last Glacial Maximum have created “resource legacies” seen today as gradients of biogeochemical properties in soils and lakes. Associated with these gradients in organic matter, limiting nutrients, and salts are contemporary organism abundances and biodiversity.

Scottnema lindsayae is the dominant soil nematode in dry soils where its population distribution defines the limits of habitat suitability (function of organic matter, salinity, moisture) and its population variation is an indicator of environmental change.

Local, Regional and Global Connectivity

Aeolian Connectivity: To address our hypothesis that changes in aeolian transport will influence the distribution of soil organisms and ecological connectivity, PhD student Alia Khan is collecting material at about 10 sites in the MDV distributed to identify long range and within valley transport (particle collector installation at right). This research is conducted in collaboration with New Zealand researchers. (H1)

Stream ecosystem responses and biomass and organism transport from cryoconites, stream microbial mats to lakes

Microbial mats in Dry Valley streams persist through winter and are revived with summer streamflow (Fig. 1A). Tyler Kohler, PhD student, evaluated controls on mat biomass of 3 mat types (orange, black, and green) to changing hydrology over 20 years by creating smoothed trends from generalized additive mixed models (Fig. 1B) and comparing trends with Pearson Correlation Coefficients. Mat biomass collectively decreased during the middle of the record coinciding with a period of low flows and a “flood” summer (Fig. 1C).

Field Guide to MCM Biota – Byron Adams

Although the abundance and diversity MCM DV biota is low relative to most other ecosystems, recent and ongoing work reveals that representative taxa from most of the major lineages of the Tree of Life are present and functioning. Diatoms in particular serve as excellent indicators of environmental change, and MCM DV diatoms showcase this utility via the Antarctic Freshwater Diatom Database (http://huey.colorado.edu/diatoms/about/index.php).

Overview: Hypotheses of hydrologic and aeolian drivers of ecological connectivity

The McMurdo Dry Valleys (MDV) is a polar desert on the coast of East Antarctica, a region that has not yet experienced the climate warming that is now occurring elsewhere. The MCMLTER project has documented the ecological responses of the glacier, soil, stream and lake ecosystems in the MDV to a cooling trend that occurred from 1986 to 2000, which was associated with the depletion of atmospheric ozone. In anticipation of the eventual amelioration of the ozone hole in the next 50 years, our overarching hypothesis is:

Modelling, Water Tracks, and Weathering Connectivity

Over the past decade, we have developed a conceptual model that documents the connectivity of glaciers (primary source of water) to lakes on the valley floor via stream channels. The stream channels provide two important functions beyond conveyance of water and associated solutes and energy to lakes – (1) they provide habitat for algal mats that include diatom and microbial communities, and (2) they accommodate active exchange of water between the channel and the hyporheic zone underneath and adjacent to the channel.

New monitoring and Lake, Stream, and Soil Research

One of the most ambitious expansions of MCM4 is the establishment of monitoring stations beyond Taylor and Wright Valleys, into Miers and Garwood Valleys. The addition of these two unique valley systems is a perfect, natural complement to investigating the role that topological variation plays in biogeochemical processes (H3), and provides insight into the potential future conditions in Taylor Valley.

Education and Outreach

STEM Outreach: Through a partnership with CU’s 'Learn More About Climate' program, Ph. D. student Alex Mass has been engaging students in the Denver/Boulder area and beyond through their interest in Antarctica to promote learning in STEM fields. Alex held a Chancellor’s Fellowship for Excellence in STEM Education

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