Recently graduated Ph.D. Student, Kimberly Miller, published part of her dissertation in Soil Biology and Biochemistry, showing that the addition of alternative electron acceptors, ferric iron and humic acid, reduced methane fluxes in the tundra near Barrow, Alaska. This work resulted from our NSF grant to study the significance of iron and humic substances in anaerobic respiration in Arctic soils. These extracellular alternative terminal electron acceptors contribute greatly to ecosystem respiration and can limit the production and release of methane from these soils.