The combined influence of glacial retreat and penguin guano on soil greenhouse gas fluxes in South Georgia
The production and consumption of three greenhouse gasses (CO2, CH4 and N2O) were assessed based on laboratory incubations of soil cores, as well as incubation experiments with added nutrients and water. We found that soils located at a greater distance from the retreating glacier front showed a successive development, with expanding vegetation cover and increasing soil nutrient content, coinciding with increased CO2 production and CH4 consumption rates. Towards sites with an increase in penguin activity and guano deposition, the CO2 production increased by 4–16-fold while the CH4 consumption decreased by about half. N2O production rates were not affected by exposure time since glacial retreat, but increased markedly (approximately 120-fold) at the site with the highest penguin activity. Along the transect, labile C and moisture were considered the key limiting factors for CO2 production, while moisture likely explain the limitation of CH4 consumption.
For more information see:
Wang P., D'Imperio L., Biersma E.M., Ranniku R., Xu W., Tian Q., Ambus P., Elberling B. (2019). Combined effects of glacial retreat and penguin activity on soil greenhouse gas fluxes on South Georgia, sub-Antarctica. Science of the Total Environment, 135255.