Upper Pond Experiment

• Format: Dataset
• Language: unknown
• Published: McMurdo Dry Valleys LTERByrd Polar Research Center 108 Scott Hall1090 Carmack RdColumbusOH43210-1002USA(614) 292-4697 2011
• Subjects: nematodes; soil organic C; invertebrates; McMurdo; Antarctica; LTER; spatial variability; Victoria Land; Taylor Valley; Antarc*; antarcticus; Plectus antarcticus
• Online Access: http://hdl.handle.net/10255/dryad.13359; http://metacat.lternet.edu/knb/metacat/knb-lter-mcm.4009.2/xml

In January 2001, we surveyed streams and ponds above 300 m asl in Taylor Valley, South Victoria Land, Antarctica. One pond was examined in detail. Organic materials covered nearly 100% of the adjacent soil to 5-20 m from the shore, with intermittent patches to 80 m. Organic matter averaged 257 gC/m2, and totaled 1388 kg organic C on the soil around the pond. Soil moisture content (0.56 to 12.41%) decreased with distance from shore, whereas pH (7.8 to 10.8) increased with distance. Electrical conductivity was lowest in the soils less than 10 m from the pond (416 +- 94 uS/cm). Mineral soil organic C and total N concentrations were greatest between 10-30 m from the edge of the pond (1.21 +- 0.37 and 0.13 +- 0.05 mg/g soil, respectively). Soil invertebrates were present in only 50% of samples and included tardigrades, rotifers and two nematodes, Scottnema lindsayae and Plectus antarcticus. A non-parametric, discriminant function analysis based on soil moisture, soil organic carbon and electrical conductivity correctly predicted 87.0% of sites that had invertebrates and 70.8% of sites for which invertebrates were absent. Tardigrades, rotifers and Plectus were found only in the wettest soils nearest the pond whereas Scottnema was restricted to drier soils farther from shore. Other ponds and streams also showed substantial accumulations of organic matter, suggesting that upland wetlands serve as resource islands in these polar deserts that provide a source of organic matter to nearby soils.