The two commonly used approaches for estimating greenhouse gas (GHG) production from soil organic carbon (OC) are experimental and modeling studies. However, GHG emissions estimated using experimental versus modeled approaches diverge due to models not fully capturing the complexities and interactions present in natural systems, including microbial processes and their microscale interactions with OC and nutrient cycling dynamics. Few studies utilize both experimental and modeling approaches to work towards reconciling the discrepancies. I will use a combination of laboratory (incubations, high-throughput amplicon sequencing, metabolic pathway analyses of metagenomic data, and high-resolution organic matter characterization) and modeling (geochemical rate models and Bayesian probability analysis) approaches to characterize microscale controls on microbial OC decomposition. Improved understanding of these controls can aid in reconciling discrepancies between published GHG emission estimates using experimental versus modeling approaches, leading to improved estimates of future GHG emissions and subsequent global climate feedbacks.
Mentor: Dr. Susanne Liebner
Research conducted as part of a GFZ Discovery Fellowship (2019-2022) and the Geo.X Young Academy (2019-2021).
Manuscripts in prep.
Heslop, J.K., et al. “Effects of microbial and organic matter priming on C processing potentials of deep yedoma permafrost sediments.” In prep.
Conference papers
Heslop, J.K., Winkel, M., Yang, S., Walter Anthony, K.M., Spencer, R.G.M., Podgorski, D.C., Zito, P., and Liebner, S. “Microbe-substrate interactions following simulated microbial inoculation to thawed yedoma permafrost in anaerobic environments,” presented at the RCOP and ICCRE Permafrost Virtual Conference, 24-29 October 2021.
Heslop, J.K., Liebner, S., Walter Anthony, K.M., Winkel, M., Spencer, R.G.M., Podgorski, D.C., Zito, P., and Neumann, R. “MicroModel: Microscale controls on greenhouse gas production from thawing permafrost,” presented at the Symposium Focus Siberian Permafrost, 24-25 March 2021.
Heslop, J.K., M. Winkel, K. M. Walter Anthony, R.G.M. Spencer, D. C. Podgorski, P. Zito, R. Neumann, and S. Liebner. “Microbe-substrate interactions following simulated microbial inoculation to thawed yedoma permafrost,” presented at the 2020 Fall Meeting, AGU, 1-17 December 2020.
MicroModel
High Arctic
Alaska
NE Siberia
Location: 74º 55′ N, 109º 35′ W
My research objective is to couple hydrological and landscape properties with dissolved organic matter (DOM) biogeochemistry to better understand how permafrost thaw and disturbance alters carbon cycling dynamics in inland waters (e.g. ponds). Inland waters receive and process significant but poorly-constrained amounts of terrestrial carbon (C). A portion of terrestrially-derived C in inland waters is microbially processed into the greenhouse gas carbon dioxide (CO2) and outgassed into the atmospheric C pool, making inland waters important components of the global C cycle. In the Arctic, ponds represent a substantial portion of inland water surface area. Thus, C processing and subsequent CO2 outgassing from ponds could play a significant role in the Arctic C cycle and potential greenhouse gas emissions.
My research at Cape Bounty Arctic Watershed Observatory aims to quantify and characterize terrestrially-derived C export, microbial processing potentials, and CO2 flux potentials from ponds with a range of hydrological inputs (precipitation-fed versus soil water-influenced), vegetation types (mesic tundra, polar desert), and permafrost disturbance regimes (thermokarst, active layer detachment, undisturbed). This research will improve understanding of how these hydrological and landscape characteristics affect greenhouse gas production in the Canadian High Arctic, with implications towards better understanding circumpolar permafrost carbon cycling.
Mentor: Dr. Melissa Lafrenière
Project Website: www.capebountyresearch.com
Research conducted as part of a Robert Gilbert Postdoctoral Fellowship (2017-2019).
Manuscripts
Beel, C.R.*, Heslop, J.K.*, Orwin, J.F. Pope, M.A., Schevers, A.J., Hung, J.K.Y., Lafrenière, M.J., and Lamoureux, S.F. “Emerging dominance of summer rainfall in driving High Arctic terrestrial-aquatic connectivity.” Nat. Commun., 2021, doi: 10.1038/s41467-021-21759-3
*Co-first authorship
Heslop, J.K., Hung, J.K.Y., Tong, H., Simpson, M.J., Chapman, F.M., Roulet, N., Lafrenière, M.J., and Lamoureux, S.F. “Varying pond dissolved organic matter characteristics yield similar CO2 flux potentials in a disturbed High Arctic landscape.” Environmental Research Letters, In press. doi: 10.1088/1748-9326/abc913
Conference papers
Beel, C.R., Heslop, J.K., Orwin, J.F. Pope, M.A., Schevers, A.J., Hung, J.K.Y., Lafrenière, M.J., and Lamoureux, S.F. “Emerging dominance of summer rainfall in driving High Arctic terrestrial-aquatic connectivity,” presented at the 2020 Fall Meeting, AGU, 7-11 December 2020.
Heslop, J.K., Hung, J.K.Y., Chapman, F., Lafrenière, M.J., and Lamoureux, S.F. “Vegetation and disturbance drive variability in pond DOM at Cape Bounty Arctic Watershed Observatory,” presented at the 2019 Queen’s Northern Research Symposium, Kingston, Canada, 17 April 2019.
Chapman, F.M., Heslop, J.K., Lafrenière, M.J., and Lamoureux, S.F. “Hydrological Analysis of Pond Formation and Seasonal Responses in the High Arctic,” presented at the 2018 ArcticNet Annual Scientific Meeting, Ottawa, Canada, 10-14 December 2018.
Heslop, J.K., Chapman, F., Hung, J.K.Y., Lafrenière, M.J., and Lamoureux, S.F. “Hydrological and landscape controls on potential CO2 fluxes from ponds in the Canadian High Arctic,” presented at the 2018 ArcticNet Annual Scientific Meeting, Ottawa, Canada, 10-14 December 2018.
Location: 65° 02’ N, 147° 42’ W
Warming and thawing of permafrost soils removes a major barrier to soil organic carbon (SOC) mineralization, leading to the mobilization and microbial degradation of previously frozen, inactive permafrost organic carbon (OC) into the greenhouse gases carbon dioxide (CO2) and methane (CH4). Many thermokarst (thaw) lakes formed in permafrost-dominated landscapes have high rates of CO2 and CH4emission; however, the composition and biodegradability of the thawed permafrost OC as they relate to the relative magnitudes of anaerobic OC mineralization at different depths throughout the vertical profile of a thermokarst-lake talik system had, to my knowledge, never been measured. My research examined OC composition and mineralization potentials at the Vault Creek (VC) permafrost tunnel and Vault Lake, located 20 km north of Fairbanks, Alaska, USA, to better constrain these uncertainties.
PhD Advisor: Dr. Katey Walter Anthony
PhD Committee: Dr. Guido Grosse, Dr. Vladimir Romanovsky, Dr. Mingchu Zhang
Research conducted as part of an EPA STAR Fellowship (2014-2017).
Manuscripts
Heslop, J.K., Walter Anthony, K.M. Winkel, M., Sepulveda-Jauregui, A., Martinez-Cruz, K., Bondurant, A., Grosse, G., and Liebner, S. “A synthesis of methane dynamics in thermokarst lake environments.” Earth-Science Reviews, 2020, DOI: 10.1016/j.earscirev.2020.103365
Heslop, J.K., M. Winkel, K. M. Walter Anthony, R. G. M. Spencer, D. C. Podgorski, P. Zito, A. Kholodov, M. Zhang, and S. Liebner. “Increasing organic carbon biolability with depth in yedoma permafrost: ramifications for future climate change.” JGR Biogeosciences, 2019, DOI: 10.1029/2018JG004712.
Heslop, J.K., K. Walter Anthony, G. Grosse, S. Liebner, M. Winkel. “Century-scale time since permafrost thaw affects temperature sensitivity of methane production in thermokarst-lake and talik sediments.” Science of The Total Environment, 2019, DOI: 10.1016/j.scitotenv.2019.06.402.
Winkel, M., A. Sepulveda-Jaurequi, K. Martinez-Cruz, J. Heslop, R. Rijkers, F. Horn, S. Liebner, K. Walter Anthony. “Anaerobic oxidation of methane in the thaw bulb of a thermokarst lake.” Environmental Research Communications, 2019, DOI: 10.1088/2515-7620/ab1042.
Heslop, J.K., K. Walter Anthony, M. Zhang. “Utilizing pyrolysis GC-MS to characterize organic matter quality in relation to methane production in a thermokarst lake sediment core.” Organic Geochemistry, 103, 43-50, 2017, DOI: 10.1016/j.orggeochem.2016.10.013
Heslop, J.K., K. Walter Anthony, A. Sepulveda-Jaurequi, K. Martinez-Cruz, A. Bondurant, G. Grosse, M. Jones. “Thermokarst lake methanogenesis along a complete talik profile.” Biogeosciences, 12, 4317–4331, 2015, DOI: 10.5194/bg-12-4317-2015
Manuscripts in prep.
Heslop, J.K., et al. “Effects of microbial and organic matter priming on C processing potentials of deep yedoma permafrost sediments.” In prep.
Conference papers
Heslop, J.K., M. Winkel, K. M. Walter Anthony, R.G.M. Spencer, D. C. Podgorski, P. Zito, R. Neumann, and S. Liebner. “Microbe-substrate interactions following simulated microbial inoculation to thawed yedoma permafrost,” presented at the 2020 Fall Meeting, AGU, 7-11 December 2020.
Heslop, J.K., K. Walter Anthony, R.G.M. Spencer, M. Winkel, M. Zhang, S. Liebner, D. Podgorski, P. Zito, A. Kholodov. “Organic carbon biolabilty increases with depth in a yedoma permafrost profile in Interior Alaska,” presented at the 2017 Fall Meeting, AGU, New Orleans, LA, 11-15 December 2017.
Heslop, J., K. Walter Anthony, G. Grosse, P. Anthony, A. Bondurant. “Temperature sensitivity of methanogenesis in a thermokarst lake sediment core,” presented at the 2016 Fall Meeting, AGU, San Francisco, CA, 12-16 December 2016.
Heslop, J., K. Walter Anthony, A. Sepulveda-Jaurequi, K. Martinez-Cruz, A. Bondurant, G. Grosse, M. Jones. “Thermokarst lake methanogenesis along a complete talik profile,” presented at the XI International Conference on Permafrost, Potsdam, Germany, 20-24 June 2016.
Heslop, J., K. Walter Anthony, M. Zhang. “Relationships between organic matter quality and methane production in thermokarst lake sediments,” presented at the XI International Conference on Permafrost, Potsdam, Germany, 20-24 June 2016.
Heslop, J., K. Walter Anthony, A. Sepulveda-Jauregui, K. Martinez-Cruz. “Correlating permafrost organic matter composition and characteristics with methane production potentials in a first generation thermokarst lake and its underlying permafrost near Fairbanks, Alaska, USA,” presented at the 2014 Fall Meeting, AGU, San Francisco, CA, 15-19 December 2014.
Heslop, J., K. Walter Anthony, A. Sepulveda-Jauregui, K. Martinez-Cruz. “Methane production potentials in a thermokarst lake and its underlying permafrost,” presented at the 2013 Fall Meeting, AGU, San Francisco, CA, 9-13 December 2013.
Heslop, J. “Incubation study of methane production in a thermokarst-lake system,” presented at the 2013 CH4 Workshop, International Arctic Research Center, Fairbanks, AK, 6 September 2013.
Location: 68° 44′ N, 161° 24′ E
Thawing permafrost supplies dissolved organic carbon (DOC) to aquatic systems; however, the magnitude, variability and fate of this DOC is not well constrained. My research as part of the National Science Foundation (NSF) sponsored Polaris Project examined DOC respiration from seasonally thawed and near-surface permafrost soils collected from the Kolyma River Basin, north-east Russia. Results suggest that soil organic carbon (OC) heterogeneity should be considered in efforts to determine the fate of soil OC released from permafrost-dominated terrestrial ecosystems to aquatic ecosystems following permafrost thaw.
Project Website: www.thepolarisproject.org
Manuscripts
Heslop, J.K., S. Chandra, W. Sobzcak, Davydov, A. Davydova, V. Spektor, K. Walter Anthony. “Variable respiration rates from incubated permafrost soil extracts in the Kolyma River lowlands region of Northeast Siberia.” Polar Research, 36, 2017, DOI: 10.1080/17518369.2017.1305157
Conference papers
Heslop, J., K. Walter Anthony, A. Davidova, S. Davidov, N. Zimov. “A whole-stream approach to quantify headwater yedoma DOC processing in NE Siberia, Russia,” presented at the 2015 Fall Meeting, AGU, San Francisco, CA, 14-18 December 2015.
Spektor, V., J. Heslop, S. Davydov, S. Chandra, I. Kimova, N. Bakulina, E. Bulygina. “On the genesis of the Lower Kolyma yedoma based on multidisciplinary approach,” presented at the 2011 Fall Meeting, AGU, San Francisco, CA, 5-9 December 2011.
Chandra, S., J. Heslop, W.V. Sobczak, J.D. Schade, V. Spektor, R.M. Holmes, A.G. Bunn, E.B. Bulygina, K.M. Walter Anthony, K.E. Frey, N. Zimov, S.A. Zimov. “Nutrient limitation of a thermokarst lake and large river ecosystem in the Kolyma River basin (Russia),” presented at the 2010 Fall Meeting, AGU, San Francisco, CA, 13-17 December 2010.
Heslop, J., S. Chandra, W.V. Sobczak, A. Davydova, J.D. Schade, V. Spektor, R.M. Holmes, A.G. Bunn, E.B. Bulygina, K.M. Walter Anthony, K.E. Frey, N. Zimov, S.A. Zimov. “Quantifying Carbon Bioavailibility in Northeast Siberian Soils,” presented at the 2010 Fall Meeting, AGU, San Francisco, CA, 13-17 December 2010.
Heslop, J. “Russian Food Deserts,” presented at the 2010 Annual Meeting, APCG, Coeur d’Alene, ID, 15-18 September 2010.
Heslop, J., N. Torgovkin, S. Chandra, V. Spektor , E. Bulygina, A. Bunn, S. Davydov, K. Frey, R. Holmes, J. Schade, W. Sobczak, S. Zimov. “A Comparison of Three Soil Profiles along a Small Subwatershed in North Siberia,” presented at the State of the Arctic Conference, Miami, FL, 16-19 March 2010
