Stanford Advisors

All Publications

  • Effect of Drought and Heavy Precipitation on CH4 Emissions and delta C-13-CH4 in a Northern Temperate Peatland ECOSYSTEMS Perryman, C. R., McCalley, C. K., Shorter, J. H., Perry, A. L., White, N., Dziurzynski, A., Varner, R. K. 2023
  • Microtopography Matters: Belowground CH4 Cycling Regulated by Differing Microbial Processes in Peatland Hummocks and Lawns JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES Perryman, C. R., McCalley, C. K., Ernakovich, J. G., Lamit, L. J., Shorter, J. H., Lilleskov, E., Varner, R. K. 2022; 127 (8)
  • Dominance of Diffusive Methane Emissions From Lowland Headwater Streams Promotes Oxidation and Isotopic Enrichment FRONTIERS IN ENVIRONMENTAL SCIENCE Robison, A. L., Wollheim, W. M., Perryman, C. R., Cotter, A. R., Mackay, J. E., Varner, R. K., Clarizia, P., Ernakovich, J. G. 2022; 9
  • Heavy metals in the Arctic: Distribution and enrichment of five metals in Alaskan soils PLOS ONE Perryman, C. R., Wirsing, J., Bennett, K. A., Brennick, O., Perry, A. L., Williamson, N., Ernakovich, J. G. 2020; 15 (6): e0233297


    Metal contamination of food and water resources is a known public health issue in Arctic and sub-Arctic communities due to the proximity of many communities to mining and drilling sites. In addition, permafrost thaw may release heavy metals sequestered in previously frozen soils, potentially contaminating food and water resources by increasing the concentration of metals in freshwater, plants, and wildlife. Here we assess the enrichment of selected heavy metals in Alaskan soils by synthesizing publicly available data of soil metal concentrations. We analyzed data of soil concentrations of arsenic, chromium, mercury, nickel, and lead from over 1,000 samples available through the USGS Alaskan Geochemical Database to evaluate 1) the spatial distribution of sampling locations for soil metal analysis, 2) metal concentrations in soils from different land cover types and depths, and 3) the occurrence of soils in Alaska with elevated metal concentrations relative to other soils. We found substantial clustering of sample sites in the southwestern portion of Alaska in discontinuous and sporadic permafrost, while the continuous permafrost zone in Northern Alaska and the more populous Interior are severely understudied. Metal concentration varied by land cover type but lacked consistent patterns. Concentrations of chromium, mercury, and lead were higher in soils below 10 cm depth, however these deeper soils are under-sampled. Arsenic, chromium, mercury, nickel and lead concentrations exceeded average values for US soils by one standard deviation or more in 3.7% to 18.7% of the samples in this dataset. Our analysis highlights critical gaps that impede understanding of how heavy metals in thawing permafrost soils may become mobilized and increase exposure risk for Arctic communities.

    View details for DOI 10.1371/journal.pone.0233297

    View details for Web of Science ID 000539293000052

    View details for PubMedID 32492035

    View details for PubMedCentralID PMC7269202

  • Thaw Transitions and Redox Conditions Drive Methane Oxidation in a Permafrost Peatland JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES Perryman, C. R., Mccalley, C. K., Malhotra, A., Fahnestock, M., Kashi, N. N., Bryce, J. G., Giesler, R., Varner, R. K. 2020; 125 (3)