Electrical_Resistivity_Tomography_Inverted_Model_at_Site_DANA_Alaska_2014

Fire can be a significant driver of permafrost change in boreal landscapes, altering the availability of soil carbon and nutrients that have important implications for future climate and ecological succession. However, not all landscapes are equally susceptible to fire-induced change. As fire frequency is expected to increase in the high latitudes, methods to understand the vulnerability and resilience of different landscapes to permafrost degradation are needed. Geophysical and other field observations reveal details of both near-surface (<1 m) and deeper (>1 m) impacts of fire on permafrost along 11 transects that span burned-unburned boundaries in different landscape settings within interior Alaska. Data collected along the 11 transect locations include: electrical resistivity tomography (ERT), downhole nuclear magnetic resonance (NMR), active layer thickness (ALT), organic layer thickness (OLT), and plant species cover. These geospatial datasets are the foundation for the journal article: Minsley, B. J., N. J. Pastick, B. K. Wylie, D. R. N. Brown, and M. Andy Kass (2016), Evidence for nonuniform permafrost degradation after fire in boreal landscapes, J. Geophys. Res. Earth Surf., 121, 320–335, doi:10.1002/2015JF003781.

火灾是北方针叶林景观中多年冻土变化的关键驱动因子，可改变土壤碳与养分的可获取性，这对未来气候及生态演替具有重要意义。然而，并非所有景观对火灾引发的变化都具有同等的敏感性。随着高纬度地区火灾频率预计攀升，亟需建立可用于评估不同景观对多年冻土退化的脆弱性与恢复力的研究方法。地球物理与其他野外观测手段沿阿拉斯加内陆不同景观类型下的11条跨越火烧与未火烧边界的样带，揭示了火灾对近地表（<1米）及深层（>1米）多年冻土的影响细节。沿这11条样带采集的数据包括：电阻率层析成像（electrical resistivity tomography, ERT）、井下核磁共振（downhole nuclear magnetic resonance, NMR）、活动层厚度（active layer thickness, ALT）、有机质层厚度（organic layer thickness, OLT）以及植物物种盖度。这些地理空间数据集是下述期刊论文的研究基础：Minsley, B. J.、Pastick, N. J.、Wylie, B. K.、Brown, D. R. N. 及 Kass, M. Andy（2016），《北方针叶林景观火烧后多年冻土非均匀退化的证据》，《地球物理研究杂志：地表》，121卷，320–335页，DOI:10.1002/2015JF003781。