Toby Maxwell
GRC 239
650 SW Columbia Street
Bend, OR 97702
United States
Dr. Toby Maxwell is a soil scientist and ecosystem ecologist focused on co-producing research with land managers in arid and semi-arid landscapes of the Western U.S. He applies an understanding of plant-soil feedbacks to assist with restoration of upland landscapes that are under threat from plant invasions and wildfire in the context of a changing climate. His work seeks to mitigate potential negative ecosystem impacts of these disturbances, including loss of carbon storage, wildlife habitat and forage production.
Prior to joining OSU-Cascades in 2025, Toby worked at the U.S. Geological Survey’s Forest, rangeland and ecosystem science center where he developed a research program focused on understanding how soil processes drive plant invasions, and conversely how invasive plants affect soils which can feed-back to facilitate their dominance. This work was a continuation of research that began when he was a faculty member at Boise State University. Toby's research spans 7 Western U.S. states and has brought him into collaboration with, city, county, state, federal agencies as well as with private landowners, non-profits, land trusts, and more, giving him a working knowledge of how to do actionable science in large, diverse, and diversely managed landscapes.
Toby’s research uses a variety of tools including laboratory methods to assess soil health from the perspective of soil carbon-, nitrogen- and water cycling, and soil stability and structure. He also has a background in application of natural abundance and enriched stable isotopes to trace ecological processes. He also uses plant community surveys, and measurements of plant traits to assess how soil processes and properties drive competitive interactions among plant species.
GEOG 360 – Winter terms - GISCIENCE I: Geographic Information Systems and Theory
SOIL205/206 – Spring terms - Soil Science
Ongoing projects
Multi-model approach to accurate carbon storage estimates and improving monitoring plans by quantifying uncertainty-investment trade-offs on semi-arid DoD installations
Funding source: Department of defense Strategic Environmental Research and Development Program (SERDP)
Cooperative Agreement between NRCS and the Institute for Natural Resources, Oregon State University Rangeland Science Support and Technology Transfer
Funding source: NRCS
Integrated wildland fire management and restoration in support of Oregon army national guard mission readiness
Funding source: Oregon military department
Recent publications
Katz, S., Maxwell, T., de Graaff, M. A. & Germino, M. J. Invasion of perennial sagebrush steppe by shallow-rooted exotic cheatgrass reduces stable forms of soil carbon in a warmer but not cooler ecoregion. Environmental Research Communications 7, (2025).
Vahsen, M. L. Maxwell, T., et al. Phenological sensitivity of Bromus tectorum genotypes depends on current and source environments. Ecology 106, (2025).
Maxwell, T. M., Quicke, H. E., Price, S. J. & Germino, M. J. Annual grass invasions and wildfire deplete ecosystem carbon storage by >50% to resistant base levels. Communications Earth and Environment 5, (2024).
Dawson, H. R. et al. Plant functional types and tissue stoichiometry explain nutrient transfer in common arbuscular mycorrhizal networks of temperate grasslands. Functional Ecology 38, 2184–2195 (2024).
Maxwell, T. M. et al. Experimental manipulation of soil-surface albedo alters phenology and growth of Bromus tectorum (cheatgrass). Plant and Soil 487, 325–339 (2023).
Shuman, J. K. et al. Reimagine fire science for the anthropocene. PNAS Nexus 1, (2022).
Maxwell, T. M. & Germino, M. J. The effects of cheatgrass invasion on US Great Basin carbon storage depend on interactions between plant community composition, precipitation seasonality, and soil climate regime. Journal of Applied Ecology 59, 2863–2873 (2022).
Dawson, H. R., Maxwell, T. M., Reed, P. B., Bridgham, S. D. & Silva, L. C. R. Leaf Traits Predict Water-Use Efficiency in U.S. Pacific Northwest Grasslands Under Rain Exclusion Treatment. Journal of Geophysical Research: Biogeosciences 127, (2022).
Renwick, L. L. R. et al. Long-term crop rotation diversification enhances maize drought resistance through soil organic matter. Environmental Research Letters 16, (2021).
Broz, A., Retallack, G. J., Maxwell, T. M. & Silva, L. C. R. A record of vapour pressure deficit preserved in wood and soil across biomes. Scientific Reports 11, (2021).
Maxwell, T. M. & Silva, L. C. R. A State Factor Model for Ecosystem Carbon–Water Relations. Trends in Plant Science vol. 25 652–660 (2020).
Field-based vegetation and soil analyses on military lands in Oregon
Funding source: U.S. Geological survey – cooperative ecosystem studies unit
Impact of diversity in the pool of exotic species invading rangelands: response of soil resources, productivity and restoration potential
Funding source: USDA NIFA - Sustainable Agroecosystems