Hello. We are ecologists at the University of Oregon, studying how plant populations, species, and communities are changing in response to climate change and other global changes.


We ask basic ecological questions about what processes shape ecological communities while also building capacity for forecasting future changes in species distributions and community composition. Species distributions and phenologies (timing) are reshuffling due to species-specific responses to changing climate and human-mediated movements of species. What are the implications of this reshuffling for the ecological communities that people have come to know and rely on in various ways?

We have worked on a variety of topics, including:

  • controls of species distributions
  • source-sink dynamics
  • causes and consequences of species invasions
  • phenology and climate change
  • plant-soil feedbacks

We continue various projects exploring these topics, but current work in the lab is focused on a few particular questions:

  1. How are phenological differences among species causing phenological reshuffling, and how does this influence their interactions and coexistence?
  2. How do interactions between plant species and fungi and bacteria (above- and below-ground) impact plant fitness, species interactions and coexistence?
  3. How are fungi responding to changing climate, and what factors control the distributions of fungal species at local to continental scales?
  4. How will changing climate and spread of introduced species influence the composition of ecological communities?
  5. How will forest demography (trees and understories) change with increased climate variability?
  6. Will rapid evolution potentially rescue species from climate change? with Seema Sheth

About Us


Institute of Ecology & Evolution
Department of Biology
University of Oregon

We are a research group in the Institute of Ecology and Evolution at the University of Oregon studying what controls the distributions of species and composition of communities in forest and rangeland ecosystems. This work has become more challenging and more urgent in this era of rapid global changes. Climate change and unprecedented rates of species’ movement around the globe (biological invasions) are reshuffling communities in space and time. We use these changes as natural experiments to understand communities, while also building capacity to predict changes in the coming decades. We use field experiments, greenhouse experiments, theory, and demographic and statistical modeling that can test hypotheses and quantify processes at different spatial and temporal scales

Jeff Diez

Associate Professor


PhD., Ecology, Institute of Ecology, Athens, GA
B.A., M.A. Biology, University of Pennsylvania, Philadelphia, PA
Before arriving at U Oregon, I was assistant professor at UC Riverside and had postdoc positions at ETH Zürich, Switzerland, working with Jonathan Levine, at the University of Michigan, working with Inés Ibánez, and in New Zealand working with Richard Duncan and Phil Hulme.

Sarah Erskine

PhD Student


2016 B.S. Environmental Science, Biology Minor, University of Vermont
Research interests: Plants! Their phenology, interactions, and coexistence in a changing world.

Jeremy Collings

PhD Student


B.S., Conservation Biology, State University of New York at Cortland
I am interested in theoretical and empirical approaches to better understanding how species interactions shape biological communities. In particular, I am studying how interactions between plants and microbes structure plant communities.

Emily Cook

Research assistant / Lab Manager

Ella Bloom

Undergraduate researcher

Sally Thompson

Undergraduate researcher

Emma Freedman

Undergraduate researcher

Macy Patel

Undergraduate researcher

Former members

Melissa Milbrandt, Undergraduate researcher (graduated UO 2021)

Teresa Bohner, PhD. (graduated UCR 2020)

Courtney Collins, PhD. (graduated UCR 2019)

Jolene Saldivar, PhD. (UCR 2019 - Rankin Lab)

Soren Weber, MS. (graduated UCR 2017)

many valued UCR undergraduate students… to come asap.



Recent Publications –

(Full list here)



  • Bohner, T. and J Diez. (2021) Tree resistance and recovery from drought mediated by multiple abiotic and biotic processes across a large geographic gradient. Science of The Total Environment 789, 147744. pdf
  • Diez, J.M., R. Boone, T. Bohner, O. Godoy. (2021) Frequency-dependent tree performance depends on climate. Ecology. 102(4):e03284. pdf
  • Qin, Z. J. E. Zhang *, A. DiTommaso, J. M. Diez, Y. Zhao, and F. G. Wang. (2021) Predicting the Potential Distribution of Three Allergenic Invasive Ambrosia (ragweed) Species in Asia. Journal of Environmental Informatics. 10.1002/ecy.3284
  • Camarero, J.J., Gazol, A., Sánchez-Salguero, R., Fajardo, A., McIntire, E.J.B., Gutiérrez, E., Batllori, E., Boudreau, S., Carrer, M., Diez, J., Dufour-Tremblay, G., Gaire, N.P., Hofgaard, A., Jomelli, V., Kirdyanov, A.V., Lévesque, E., Liang, E., Linares, J.C., Mathisen, I.E., Moiseev, P.A., Sangüesa-Barreda, G., Shrestha, K.B., Toivonen, J.M., Tutubalina, O.V. and Wilmking, M. (2021), Global fading of the temperature–growth coupling at alpine and polar treelines. Glob. Change Biol., 27: 1879-1889. pdf
  • Reinhart, KO, Bauer, JT, McCarthy-Neumann, S, et al. Globally, plant-soil feedbacks are weak predictors of plant abundance. Ecol Evol. 2021; 11: 1756– 1768. pdf


  • Collins, C., Spasojevic, M., Alados, C., Aronson, E., Benavides, J., Cannone, N., Caviezel, C., Grau, O., Guo, H., Kudo, G., Kuhn, N., Müllerová, J., Phillips, M., Pombubpa, N., Reverchon, F., Shulman, H., Stajich, J., Stokes, A., Weber, S., Diez, J. (2020) Belowground Impacts of Alpine Woody Encroachment are determined by Plant Traits, Local Climate and Soil Conditions. Global Change Biology
  • Yan, X., Diez, J., Huang, K., Li, S., Luo, X., Xu, X., Su, F., Jiang, L., Guo, H., Hu, S. (2020). Beyond resource limitation: an expanded test of the niche dimension hypothesis for multiple types of niche axes Oecologia. 193(3), 689-699.
  • Diez, J., Kauserud, H., Andrew, C., Heegaard, E., Krisai-Greilhuber, I., Senn-Irlet, B., Høiland, K., Egli, S., Büntgen, U. (2020). Altitudinal upwards shifts in fungal fruiting in the Alps Proceedings of the Royal Society B 287(1919), [link].
  • S. R. Brown, A. Baysinger, P. M. Brown, J. L. Cheek, J. M. Diez, C. M. Gentry, T. A. Grant, H. D. Grissino-Mayer, J. St. Jacques, D. A. Jordan, M. L. Leef, M. K. Rourke, J. H. Speer, C. E. Spradlin, - J. T. Stevens, J. R. Stone, B. Van Winkle, and N. E. Zeibig-Kichas. (2020) Fire history across forest types in the southern Beartooth Mountains, Wyoming. Tree-Ring Research 76 (1): 27–39.
  • Rafferty, N., J. Diez, D. Bertelsen. (2020) Changing climate drives divergent and nonlinear shifts in flowering phenology across elevations. Current Biology. 30(3), 432-441 [link] Bohner, T., Diez, J. (2020). Extensive mismatches between species distributions and performance and their relationship to functional traits Ecology Letters 23(1), 33-44. [link]


  • Collins, C., Bohner, T. & Diez, J. (2019). Plant-soil feedbacks and facilitation influence the demography of herbaceous alpine species in response to woody plant range expansion. Frontiers in Ecology and Evolution, 7, 417.
  • Krah, F.-S., Büntgen, U., Schaefer, H., Müller, J., Andrew, C., Boddy, L., J.M. Diez, et al. (2019). European mushroom assemblages are darker in cold climates. Nature Communications, 10, 2890.
  • Bradley, B. A., B. Laginhas, R. Whitlock, A.E. Bates, G. Bernatchez, J.M. Diez, J. M. Allen, R.Early, J. Lenoir, M. Vilà, C.J.B. Sorte. (2019) Disentangling the abundance-impact relationship for invasive species. PNAS, 116, 9919–9924.
  • Xu, X., L. Wolfe, J. Diez, Y. Zheng, H. Guo, S. Hu. (2019) Differential germination strategies of native and introduced populations of the invasive species Plantago virginica. Neobiota. 43: 101–118
  • Peterson, A.T., Anderson, R.P., Beger, M., Bolliger, J., Brotons, L., Burridge, C.P., et al. (2019). Open access solutions for biodiversity journals: Do not replace one problem with another. Divers. Distrib., 25, 5–8.
  • Andrew, C., J. Diez, T.Y. James and H. Kauserud. (2019) Fungarium specimens - a largely untapped source in global change biology and beyond. Philosophical Transactions Roy. Soc. B. 374, 20170392.
  • Weber, S.E., Diez, J.M., Andrews, L.V., Goulden, M.L., Aronson, E.L. & Allen, M.F. (2019). Responses of arbuscular mycorrhizal fungi to multiple coinciding global change drivers. Fungal Ecology, 40, 62–71.


  • Collins, C.G., Stajich, J.E., Weber, S.E., Pombubpa, N. & Diez, J.M. (2018). Shrub range expansion alters diversity and distribution of soil fungal communities across an alpine elevation gradient. Molecular Ecology, 27, 2461–2476.
  • Alexander, J.M., Diez, J. M., Usinowicz, J., Hart, S.P. (2018). Species' distributions as a coexistence problem: a reply to Godsoe et al.. Trends in Ecology and Evolution.


  • Gange, A. C., Heegaard, E., Boddy, L., Andrew, C., Kirk, P., Halvorsen, R., Kuyper, T. W., Bässler, C., Diez, J., Heilman-Clausen, J., Høiland, K., Büntgen, U. and Kauserud, H. (2017), Trait-dependent distributional shifts in fruiting of common British fungi. Ecography 41(1), 51-61. [link]
  • Andrew, C., Heegaard, E., Kirk, P. M., Bässler, C., Heilmann-Clausen, J., Krisai-Greilhuber, I., et al. (2017). Big data integration: Pan-European fungal species observations' assembly for addressing contemporary questions in ecology and global change biology. Fungal Biology Reviews, 31(2), 1–11.


  • Alexander, J. M., Diez, J. M., Hart, S. P., & Levine, J. M. 2016. When Climate Reshuffles Competitors: A Call for Experimental Macroecology. Trends in Ecology & Evolution.
  • Heegaard, E., L. Boddy, J.M. Diez, R. Halvorsen, H. Kauserud, T. W. Kuyper, C. Bässler, U. Büntgen, A. C. Gange, I. Krisai-Greilhuber, C. J. Andrew, F. Ayer, K. Høiland, P. Kirk, S. Egli. (2016) Fine-scale spatiotemporal dynamics of fungal fruiting: prevalence, amplitude, range and continuity. Ecography.
  • Collins, C.G., C.J. Carey, E.L. Aronson, C.W. Kopp, J. M. Diez. 2016. Direct and indirect effects of native range expansion on soil microbial community structure and function. Journal of Ecology.
  • Elmendorf, S. C., K. D. Jones, B. I. Cook, J. M. Diez, C. A. F. Enquist, R. A. Hufft, M. O. Jones, S. J. Mazer, A. J. Miller-Rushing, D. J. P. Moore, M. D. Schwartz, and J. F. Weltzin. 2016. The plant phenology monitoring design for The National Ecological Observatory Network. Ecosphere 7(4).


  • Alexander, J.M., J.M. Diez, J.M., J.M. Levine. 2015. Novel competitors shape species' responses to climate change. Nature 525, 515–518.
  • Büntgen U, Egli S, Galván JD, Diez JM, Aldea J, Latorre J, F. Martínez-Peña. 2015. Drought-induced changes in the phenology, productivity and diversity of Spanish fungi. Fungal Ecology 16: 6-18
  • González-Moreno, Pablo, J.M. Diez, D.M. Richardson, M. Vilá. 2015. Beyond climate: disturbance niche shifts in invasive species. Global Ecology and Biogeography. 24(3):360-370.

Full list of publications