Remeasurements of organic layer carbon stocks after ten years in Alaskan forests and peatlands

We measured organic layer (OL) recovery and carbon stocks in dead woody debris and soil pools a decade following wildfire in black spruce forests of interior Alaska. Previous study at these research plots has shown the strong role landscape position plays in governing the proportion of OL consumed during fire, and post-fire revegetation. Here, we show that landscape position likely influences fire dynamics in these stands through changes in mineral soil texture. The content of fine textured materials in underlying mineral soils was positively related to OL depths measured one and ten years post-fire, and there was an interaction between soil texture and elevation in governing OL consumption, and OL recovery a decade following fire. OL depths a decade post-fire were 2 cm greater than one year post-fire, with a range of 19 cm of accumulation to 9 cm of subsidence. Subsidence was inversely related to the percentage of fine textures within the parent material. The most influential factor determining the accumulation of soil organic carbon stocks a decade following wildfire was the interaction between landscape position and the presence of fine textured soil. As such, parent material texture interacted with biological processes to govern the recovery of organic soils.