(Supplemental Table 2) Plant characteristics, GHG fluxes, and soil chemical and microbial properties in experimental treatments in Alexandra Fiord

• Main Authors: Lamb, Eric G, Han, Sukkyun, Lanoil, Brian D, Henry, Gregory HR, Brummell, Martin E, Banerjee, Samiran, Siciliano, Steven D
• Format: Dataset
• Language: English
• Published: PANGAEA 2011
• Subjects: Activation energy; Alexandra_Fiord_sites; Ammonium; standard deviation; amoA gene; copy number in sediment; Carbon; organic; total; Carbon dioxide; flux; CrenamoA gene; DATE/TIME; Denaturing gradient gel electrophoresis (DGGE); Ellesmere Island; Canadian Arctic Archipelago; Experimental treatment; Fourier transform infrared trace gas analyzer (FTIR-TGA; Gasmet DX-4015); HAND; Height; International Polar Year (2007-2008); IPY; Methane; Nitrate; Nitrogen; dissolved; Nitrous oxide; Nitrous oxide reductase gene; Arctic; Canada; Alexandra Fiord; Arctic Archipelago; International Polar Year; Tundra
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.815197; https://doi.org/10.1594/PANGAEA.815197

We evaluated above- and belowground ecosystem changes in a 16 year, combined fertilization and warming experiment in a High Arctic tundra deciduous shrub heath (Alexandra Fiord, Ellesmere Island, NU, Canada). Soil emissions of the three key greenhouse gases (GHGs) (carbon dioxide, methane, and nitrous oxide) were measured in mid-July 2009 using soil respiration chambers attached to a FTIR system. Soil chemical and biochemical properties including Q10 values for CO2, CH4, and N2O, Bacteria and Archaea assemblage composition, and the diversity and prevalence of key nitrogen cycling genes including bacterial amoA, crenarchaeal amoA, and nosZ were measured. Warming and fertilization caused strong increases in plant community cover and height but had limited effects on GHG fluxes and no substantial effect on soil chemistry or biochemistry. Similarly, there was a surprising lack of directional shifts in the soil microbial community as a whole or any change at all in microbial functional groups associated with CH4 consumption or N2O cycling in any treatment. Thus, it appears that while warming and increased nutrient availability have strongly affected the plant community over the last 16 years, the belowground ecosystem has not yet responded. This resistance of the soil ecosystem has resulted in limited changes in GHG fluxes in response to the experimental treatments.