Soils

Field sampling of efflux

A continuous automated system for soil carbon efflux with clear acrylic chambers will be run for 4-5 consecutive days at one plot within a burn interval while the other plots will be measured twice per week with a clear-chamber portable soil respiration system. The automated system will be rotated weekly across burn intervals. In each area, three of the six vegetation survey plots in the control (unburned for >70 years), 1x burned, and ≥ 2x burned frequencies will be randomly selected and measured with eight replicate sample locations per plot (1 area × 3 burn frequencies × 3 plots × 8 replicates = 72).

Field sampling of depth to permafrost

Depth to soil ice and frozen ground will be assessed in September of 2018 and 2019 using a steel rod to maximum penetration in all soil efflux measurement plots.

Laboratory Incubations

Long-term soil C loss potential and short-term temperature sensitivity of the organic and mineral (0-20 cm, >20-30 cm, >30-45 cm) soil organic matter will be estimated over the course of a 365-day laboratory incubation. Replicates will include 3 areas x 3 burn frequencies × 3 plots x 4 depths for a total of 108 incubations (1 L).