Insights Into Fire-based Soil Temperature and Moisture Changes From a Long-term Data Set in Alaska

• Main Authors: Manies, Kristen, Harden, Jennifer, Cable, William, Hollingsworth, Jamie
• Format: Conference Object
• Language: unknown
• Published: 2020
• Subjects: permafrost; Alaska
• Online Access: https://epic.awi.de/id/eprint/53510/; https://epic.awi.de/id/eprint/53510/1/essoar_10505527_1.pdf; https://hdl.handle.net/10013/epic.35843d84-eab8-4c97-8cd0-e258c00687f8

Wildfires are one of the main sources of disturbance in boreal forests. Post-fire changes to soil temperature and moisture regimes can have wide-ranging impacts on boreal forests including the depth at which permafrost is found, vegetation recovery, and carbon and nitrogen cycling. Surface soil temperatures increase following fire, due to loss of shading from tree canopies and a thinner surface organic layer. Post-fire soil temperature and moisture regimes also change due to reduced transpiration and changes in surface albedo. The duration of these changes depends on factors such as region, fire intensity, and soil texture. Here we present results from a long-term (1999 to present) dataset of soil conditions for four black spruce boreal forest sites located in Interior Alaska across burn and permafrost gradients: 1) burned, no permafrost, 2) unburned, no permafrost, 3) burned, with permafrost, and 4) unburned, with permafrost. The data from these sites demonstrate how both burning and the presence of permafrost influence soil temperature and moisture, as well as the timing of seasonal changes, for over twenty years. In addition, we discuss the challenges of maintaining and collecting data from field instruments deployed for decades in harsh conditions. All data discussed in this presentation will be available on the Bonanza Creek Long-term Ecological Research (LTER) website and is available for future studies.