PARENT SESSION
Poster Session 19: Biodiversity
Wednesday, August 10, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal
Sources of soil moisture and their impacts on soil biodiversity in Taylor Valley, Antarctica.
Nkem, Johnson*,1, Wall, Diana1, Virginia, Ross2, Barrett, John2, Adams, Byron3, 1 Colorado State University, Fort Collins, CO 80523, USA2 Dartmouth College, Hanover, NH 03755, USA3 Brigham Young University, Provo, UT 84602, USA
ABSTRACT- Taylor Valley is one of the McMurdo Dry Valleys and is a polar desert habitat with low soil moisture content (
1%) and soil biodiversity. Liquid water availability is crucial for soil invertebrates and is a major factor in the creation of suitable habitats for establishment of soil communities. Snowmelt is one source of moisture to soils but is constrained by high sublimation. Soil moisture is also derived from groundwater seeps representing subsurface sources from melting permafrost. To examine snowpack sources of moisture we erected snow fences 1 m high and 6 m long in two lake basins; Fryxell and Bonney, and for comparison we also identified six groundwater seeps in the Fryxell Basin (F6 and F7) to evaluate soil invertebrate response to moisture. Soil samples were taken after snowmelt at 0.9 m intervals to a distance 3.6 m from the snow fence in the austral summer of 2000/01, 2002/03, and 20003/04, while the seeps were sampled in 2001/02 and 2002/03 seasons. Soil moisture content was significantly higher (P<0.0001) in groundwater seep soils than in soils under snowpacks. Community richness differed between the two sources of moisture, with one taxon (nematodes) in snow fence soils, and three taxa (nematodes, rotifers and tardigrades) in the groundwater seep soils. Nematode species richness was higher in the snow fence soils. Soil moisture source, interacting with soil properties influences soil invertebrate abundance and diversity.
Key words: soil moisture, soil biiodiversity, Antarctica, polar desert