Research Interests

Karis McFarlane’s research uses radiocarbon to track carbon as it cycles within ecosystems and between ecosystems and the atmosphere. Her research addresses the complex relationship between climate change and the role ecosystems play in the carbon cycle from plot to regional scales. Karis has worked in managed and natural forests, prairie, croplands, and wetlands to investigate the factors influencing the amount and longevity of carbon stored in soil, the transfer of plant carbon into soil, and the source of carbon (new or old) used by soil microorganisms and released back to the atmosphere to improve our understanding and modeling of these complex earth systems.

Research and Professional Experience

2010–present, Earth Scientist, Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory

Mentoring

• Postdoc Mentor: Paul Zander (2024-present), Manisha Dolui (co-mentor, 2023-2025), Katherine Grant (2021-2024), Kimber Moreland (2020-2023); Kari Finstad (2016–2019), Claire Phillips (2012–2013)
• Graduate Mentor: Zachary Malone (UC Merced, 2024-2025), Manisha Dolui (UC Merced, 2021-2023), Alexandra Hedgpeth (UCLA, 2019-2025), Margaret Capoocci (University of Delaware, 2019-2023), Nina Zhang (Colorado State, 2016-present), Kimber Moreland (UC Merced, 2018-2021), Allegra Mayer (UC Berkeley, 2017–2021)
• Undergraduate Mentor: Teacher and Researcher (STAR) Internship Program (2015–2017, 2010); ROTC Program (2015–2016); NNSA Minority Serving Institution (MSI) Internship Program (2013); DOE Science Undergraduate Laboratory Internships (SULI, 2013, 2022)

Ph.D., Forest Engineering, Oregon State University, 2007

M.S., Forest and Natural Resources Management, SUNY-ESF, 2003

B.S., Environmental Science, DePaul University University, 2001

Hedgpeth, A. L., A. M. Hoyt, K. Cavanaugh, K. J. McFarlane and D. F. Cusack (2025). "From the Top: Surface-derived Carbon Fuels Greenhouse Gas Production at Depth in a Neotropical Peatland." Biogeosciences. EGUsphere 2024: 1-36. 10.5194/egusphere-2024-1279

Min, K., E. Nuccio, E. Slessarev, M. Kan, K. J. McFarlane, E. Oerter, A. Jurusik, G. Sanford, K. D. Thelen, J. Pett-Ridge and A. A. Berhe (2025). "Deep-rooted perennials alter microbial respiration and chemical composition of carbon in density fractions along soil depth profiles." Geoderma 455.10.1016/j.geoderma.2025.117202

McFarlane, K. J., S. Mambelli, R. C. Porras, D. B. Wiedemeier, M. W. I. Schmidt, T. E. Dawson and M. S. Torn (2024). "Soil Carbon Stocks Not Linked to Aboveground Litter Input and Chemistry of Old-growth Forest and Adjacent Prairie." Radiocarbon 66(5): 919-936.10.1017/RDC.2024.5

McFarlane, K. J., D. F. Cusack, L. H. Dietterich, A. L. Hedgpeth, K. M. Finstad and A. T. Nottingham (2024). "Experimental warming and drying increase older carbon contributions to soil respiration in lowland tropical forests." Nat Commun 15(1): 7084.10.1038/s41467-024-51422-6

Mayer, A. C., K. J. McFarlane and W. L. Silver (2024). "The effect of repeated hurricanes on the age of organic carbon in humid tropical forest soil." Glob Chang Biol 30(4): e17265.10.1111/gcb.17265

Grant, K. E., M. N. Repasch, K. M. Finstad, J. D. Kerr, M. Marple, C. J. Larson, T. A. B. Broek, J. Pett-Ridge and K. J. McFarlane (2024). "Diverse organic carbon dynamics captured by radiocarbon analysis of distinct compound classes in a grassland soil." Biogeosciences 21(19): 4395-4411.10.5194/bg-21-4395-2024

Finstad, K. M., E. E. Nuccio, K. E. Grant, T. A. B. Broek, J. Pett-Ridge and K. J. McFarlane (2024). "Radiocarbon Analysis of Soil Microbial Biomass Via Direct Chloroform Extraction." Radiocarbon 66(5): 854-862.10.1017/Rdc.2023.80

Cusack, D., L. H. Dietterich, N. J. Bouskill, S. S. Chacon, A. L. Cordeiro and K. McFarlane (2024). Panama Rainforest Changes with Experimental Drought (PaRChED): Initial Effects of Partial Throughfall Exclusion on Soil Dynamics in Lowland Forests Across Variation in Rainfall and Soil Fertility. The First 100 Years of Research on Barro Colorado: Plant and Ecosystem Science. H. Muller-Landau and S. J. Wright. Washington, DC, Smithsonian Institution Scholarly Press. 2: 591-599.10.5479/si.26880820

Cordeiro, A. L., D. F. Cusack, L. H. Dietterich, W. C. Hockaday, K. J. Mcfarlane, V. Sivapalan, A. Hedgpeth, A. Neupane, L. Colburn, W. Konwent, G. Oppler, J. C. Reu, E. Valdes and S. J. Wright (2024). "Root Characteristics Vary with Depth Across Four Lowland Seasonal Tropical Forests." Ecosystems 27(8): 1104-1122.10.1007/s10021-024-00941-w

Capooci, M., A. L. Seyfferth, C. Tobias, A. S. Wozniak, A. Hedgpeth, M. Bowen, J. F. Biddle, K. J. McFarlane and R. Vargas (2024). "High methane concentrations in tidal salt marsh soils: Where does the methane go?" Glob Chang Biol 30(1): e17050.10.1111/gcb.17050

Anuo, C. O., L. Li, K. C. Moreland, K. J. McFarlane, A. Malakar, J. A. Cooper, B. Maharjan and M. Kaiser (2024). "Storage and persistence of organic carbon in the upper three meters of soil under arable and native prairie land use." Plant and Soil.10.1007/s11104-024-06850-0

Finstad, K. M., E. E. Nuccio, K. E. Grant, T. A. B. Broek, J. Pett-Ridge and K. J. McFarlane (2024). "Radiocarbon Analysis of Soil Microbial Biomass Via Direct Chloroform Extraction." Radiocarbon 66(5): 854-862.10.1017/Rdc.2023.80

Foley, M. M., S. J. Blazewicz, K. J. McFarlane, A. Greenlon, M. Hayer, J. A. Kimbrel, B. J. Koch, V. L. Monsaint-Queeney, K. Morrison, E. Morrissey, B. A. Hungate and J. Pett-Ridge (2023). "Active populations and growth of soil microorganisms are framed by mean annual precipitation in three California annual grasslands." Soil Biology and Biochemistry 177: 108886. doi:10.1016/j.soilbio.2022.108886

Lang, A. K., J. Pett-Ridge, K. J. McFarlane and R. P. Phillips (2023). "Climate, soil mineralogy and mycorrhizal fungi influence soil organic matter fractions in eastern US temperate forests." Journal of Ecology 111(6): 1254-1269. Doi: 10.1111/1365-2745.14094

Martinez, P., R. A. Lybrand, K. J. McFarlane, M. Dor, A. C. Gallo, A. Mayedo, F. Marini, P. Vidal-Torrado and M. Kleber (2023). "Organic carbon enables the biotic engineering of beneficial soil structure in Profundihumic and Haplic Ferralsols." European Journal of Soil Science 74(5): e13415. doi: 10.1111/ejss.13415

McFarlane K J, Throckmorton HM, Heikoop JM, Newman BD, Hedgpeth AL, Repasch MN, et al. (2022). Age and chemistry of dissolved organic carbon reveal enhanced leaching of ancient labile carbon at the permafrost thaw zone. Biogeosciences, 19(4), 1211-1223.  doi:10.5194/bg-19-1211-2022.

Kolton M, Weston DJ, Mayali X, Weber PK, McFarlane KJ, Pett-Ridge J, et al. (2022). Defining the Sphagnum Core Microbiome across the North American Continent Reveals a Central Role for Diazotrophic Methanotrophs in the Nitrogen and Carbon Cycles of Boreal Peatland Ecosystems. mBio, 13(1), e03714-03721.  doi:10.1128/mbio.03714-21.

Moreland K, Tian ZY, Berhe AA, McFarlane KJ, Hartsough P, Hart SC, et al. (2021). Deep in the Sierra Nevada critical zone: saprock represents a large terrestrial organic carbon stock. Environmental Research Letters, 16(12), 124059.  doi:10.1088/1748-9326/ac3bfe

Wilson RM, Griffiths NA, Visser A, McFarlane KJ, Sebestyen SD, Oleheiser KC, Bosman S, Hopple AM, Tfaily MM, Kolka RK, Hanson PJ, Kostka JE, Bridgham SD, Keller JK, Chanton JP (2021). Radiocarbon analyses quantify peat carbon losses with increasing temperature in a whole ecosystem warming experiment. Journal of Geophysical Research Biogeosciences,126, e2021JG006511. doi: 10.1029/2021JG006511.

Oerter E, Slessarev E, Visser A, Min KJ, Kan MG, McFarlane KJ, et al. (2021). Hydraulic redistribution by deeply rooted grasses and its ecohydrologic implications in the southern Great Plains of North America. Hydrological Processes, 35(9), e14366. doi:10.1002/hyp.14366

Min K, Slessarev E, Kan M, McFarlane K, Oerter E, Pett-Ridge J, Nuccio E, Berhe AA (2021) Active microbial biomass decreases, but microbial growth potential remains similar across soil depth profiles under deeply- vs. shallow-rooted plants. Soil Biology and Biochemistry: 162, 108401. doi: 10.1016/j.soilbio.2021.108401.

Broek TAB, Ognibene TJ, McFarlane KJ, Moreland KC, Brown TA, Bench G (2021) Conversion of the LLNL CAMS 1 MV biological AMS system to a semi-automated natural abundance ¹⁴C spectrometer: system optimization and performance evaluation. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms: 499, 124-132. doi:10.1016/j.nimb.2021.01.022

Finstad K, van Straaten O, Veldkamp E, McFarlane K (2020) Soil carbon dynamics following land use changes and conversion to oil palm plantations in tropical lowlands inferred from radiocarbon. Global Biogeochem. Cycles: 34, e2019GB006461. doi:10.1029/2019GB006461

Slessarev, EW, Nuccio EE, McFarlane KJ, Ramon C, Saha M, Firestone MK, Pett-Ridge J (2020) Quantifying subsoil organic C accumulation under switchgrass (Panicum virgatum) across a soil texture gradient using natural abundance 14C. Global Change Biology Bioenergy. doi: 10.1111/gcbb.12729

McFarlane KJ, Hanson PJ, Iversen CM, Phillips JR, and Brice DJ (2018) Local spatial heterogeneity of Holocene carbon accumulation throughout the peat profile of an ombrotrophic Northern Minnesota bog. Radiocarbon 60(3): 941-962.  https://doi.org/10.1017/RDC.2018.37

 

Full publication list available here:

https://orcid.org/0000-0001-6390-7863

https://www.researchgate.net/profile/Karis-Mcfarlane

https://scholar.google.com/citations?user=klmvnT8AAAAJ&hl=en

• DOE Office of Science Early Career Fellowship, 2016–present
• PLS Outstanding Mentor Award, 2017
• Best Poster Award-AEED, Postdoc Symposium, 2010