Professional and Biographical Information


Ph.D., University of Alaska Fairbanks (2014)
B.A., Middlebury College (2005)

Research Interests

My research focuses on how species traits and interactions shape community structure and ecosystem function. I primarily study how fine-scale belowground processes contribute to broad-scale ecosystem responses to a warming climate and associated changes in disturbance regimes. I focus on investigating the role of plant-fungal interactions in carbon and nitrogen cycling, community assembly after disturbance, and landscape patterns of vegetation change. I explore these research themes primarily in Arctic tundra and boreal ecosystems of Alaska and Siberia (research overview).

Teaching Interests

I aim to help students explore the most important environmental issues of our time. In the courses I teach, we will model the scientific process with data collection and interpretation, writing, discussions, and presentations. Students will attain an array of scientific skills to study and communicate about the natural environment and social-ecological systems. I focus on fostering critical thinking that facilitates student engagement in environmental studies, whether that is through scientific inquiry or science communication. In the classroom and through research mentorship, I strive to highlight the connections between environmental science and issues important to society.

Recent Publications

  • Dial, R. J., Maher, C. T., Hewitt, R. E., & Sullivan, P. F. (2022). Sufficient conditions for rapid range expansion of a boreal conifer. Nature, 608(7923), 546–551.

  • Hewitt, R. E., Alexander, H. D., Izbicki, B., Loranty, M. M., Natali, S. M., Walker, X. J., & Mack, M. C. (2022). Increasing tree density accelerates stand-level nitrogen cycling at the taiga–tundra ecotone in northeastern Siberia. Ecosphere, 13(7), e4175.

  • Ernakovich, J. G., Barbato, R. A., Rich, V. I., Schädel, C., Hewitt, R. E., Doherty, S. J., Whalen, E. D., Abbott, B. W., Barta, J., Biasi, C., Chabot, C. L., Hultman, J., Knoblauch, C., Vetter, M. C. Y. L., Leewis, M.-C., Liebner, S., Mackelprang, R., Onstott, T. C., Richter, A., … Winkel, M. (2022). Microbiome assembly in thawing permafrost and its feedbacks to climate. Global Change Biology, 28(17), 5007–5026.

  • Hewitt, R. E., Alexander, H. D., Miller, S. N., & Mack, M. C. (2022). Root-associated fungi not tree density influences stand nitrogen dynamics at the larch forest–tundra ecotone. Journal of Ecology, 110(6), 1419–1431.

  • Curasi, S. R., Fetcher, N., Hewitt, R. E., Lafleur, P. M., Loranty, M. M., Mack, M. C., May, J. L., Myers-Smith, I. H., Natali, S. M., Oberbauer, S. F., Parker, T. C., Sonnentag, O., Vargas Zesati, S. A., Wullschleger, S. D., & Rocha, A. V. (2022). Range shifts in a foundation sedge potentially induce large Arctic ecosystem carbon losses and gains. Environmental Research Letters, 17(4), 045024.

  • Jasinski, B. L., Hewitt, R. E., Mauritz, M., Miller, S. N., Schuur, E. A. G., Taylor, M. A., Walker, X. J., & Mack, M. C. (2022). Plant foliar nutrient response to active layer and water table depth in warming permafrost soils. Journal of Ecology, 110(5), 1201–1216.

  • Hollingsworth, T. N., Breen, A. L., Hewitt, R. E., & Mack, M. C. (2021). Does fire always accelerate shrub expansion in Arctic tundra? Examining a novel grass-dominated successional trajectory on the Seward Peninsula. Arctic, Antarctic, and Alpine Research, 53(1), 93–109.

  • Kwon, T., Shibata, H., Kepfer-Rojas, S., Schmidt, I. K., Larsen, K. S., Beier, C., Berg, B., Verheyen, K., Lamarque, J.-F., Hagedorn, F., Eisenhauer, N., Djukic, I., TeaComposition Network, Kwon, T., Shibata, H., Kepfer-Rojas, S., Schmidt, I. K., Larsen, K. S., Beier, C., … Tóth, Z. (2021). Effects of Climate and Atmospheric Nitrogen Deposition on Early to Mid-Term Stage Litter Decomposition Across Biomes. Frontiers in Forests and Global Change, 4.

  • Maher, C. T., Dial, R. J., Pastick, N. J., Hewitt, R. E., Jorgenson, M. T., & Sullivan, P. F. (2021). The climate envelope of Alaska’s northern treelines: Implications for controlling factors and future treeline advance. Ecography, ecog.05597.