Andrew S. MacDougall

• Ph.D - Department of Botany UBC (2004)
• NSERC Postdoctoral Fellow - Department of Biology, University of Regina (2006)

My lab tests how global change transforms ecological mechanisms central to the regulation of diversity and function. It occurs across trophic levels (plant, arthropod, vertebrate), systems (terrestrial, aquatic), and spatial scales (local to global), exploring fundamental theory with relevance to conservation including sustainable food production.

Trophic Island Biogeography:

MacArthur and Wilson's classic model synthesizes a range of biogeographical processes to describe the regulation of diversity, but does not account for trophic interactions. We are testing how regional and local factors affect food web assembly in fragmented landscapes, focusing on insect-plant interactions in tallgrass prairie.

The Evolution of Spatial Pattern in Assembling Communities:

Most populations are non-randomly distributed, reflecting interactions between stochastic and deterministic niche-based processes that operate at a range of spatial and temporal scales. Using multi-hectare assembly experiments, we are testing how trophic dynamics, stochastic priority effects, and species sorting drive the evolution of spatial pattern in plant communities.

Global Drivers of Species Invasions:

Evidence linking invasion to the suppression of native diversity is equivocal. Local studies often describe negative associations between native diversity and invasion via competition, while regional studies often report habitat-mediated positive associations (the 'invasion paradox'). Using standardized multi-scale data from grasslands across the planet, this research tests how regional and local processes including human disturbances can be reconciled to explain the likely origins of the invasion paradox (a Nutrient Network project).

Stability-Diversity Dynamics:

This long-term study has determined that fire is critical for ecosystem function, but is highly destabilizing for populations of fire-dependent ground flora at local scales. Empirical data are being used to model the non-equilibrium dynamics of this system at local and regional spatial resolutions, illustrating 'a tale of two stabilities' defined by whether fire is present or continually suppressed.

Plant-Pollinator Dynamics in Agricultural Landscapes:

Global pollinator declines threaten crop production, but the magnitude of pollinator collapse remains unclear. In collaboration with ALUS, this project tests how regional and local factors relating to habitat quality and farming practices influence the composition, abundance, and diversity of native pollinators on farms, and how those influences can ultimately affect yields of pollinator-dependent crops.

Rodent Plagues on Prairie Diversity:

Small mammals influence diversity in many of the world's grasslands by selecting against palatable plants - the community can become dominated by the plants they mostly avoid. We are exploring how global environmental changes relating to plant invasion, trophic collapse, eutrophication, and habitat fragmentation may be magnifying the intensity of these 'rodent plagues', and the implications for ecosystem function including primary production and soil carbon dynamics.

Extinction:

Rarity is associated with vulnerability to extinction, yet most of the world's biological diversity is relatively uncommon in the systems where they occur. Rarity can be stabilized by a range of demographic processes that function within and across trophic levels, but many of these processes are being transformed by anthropogenic disturbances. This research explores whether stabilizing mechanisms persist despite disturbance or whether the likelihood of 'extinction debts' are increasing.

MacDougall, A.S., Vanzant, B., Sulik, J.,... & Siewert, M. B. (2026). The global extent of the grassland biome and implications for the terrestrial carbon sink. Nature Ecology & Evolution, 9: 1-12.

Yahdjian, L., et al. (2026). Insights on global rangeland ecosystem services shaped by grazing and fertilization. Frontiers in Ecology and the Environment, e70022.

Seabloom, E.W., Hobbie, S.E., MacDougall, A.S., & Borer, E. T. (2025). Multidecadal persistence of soil carbon gains on retired cropland following fertilizer cessation. Nature Geoscience, 18(10), 1014-1019.

Randall, M., & MacDougall, A.S. (2025). Niche complementarity stabilizes grassland biomass during drought and eutrophication. Oikos, e11153.

MacDougall, A.S., Esch, E.H., Dolezal, A.J., Kamm, C., Carroll, O.,... & Campbell, M. M. (2025). Ecosystem services on restored marginal farmland. Frontiers in Ecology and the Environment, e2866.

Zhang, P. et al. (2025). Dominant species predict plant richness and biomass in global grasslands. Nature Ecology & Evolution, 9, 924-936.

Carroll, O., Seabloom, E.W., Borer, E., Harpole, W.S., Wilfahrt, P.,... & MacDougall, A. S. (2025). Frequent failure of nutrients to increase plant biomass supports the need for precision fertilization in agriculture. Scientific Reports, 15: 14564.

Chen, Q. et al. (2025). Local nutrient addition drives plant diversity losses but not biotic homogenization in global grasslands. Nature Communications, 16: 4903.

Fay, P. A. et al. (2025). Interactions among nutrients govern the global grassland biomass–precipitation relationship. Proceedings of the National Academy of Sciences, 122: e2410748122.

Wu, Y., Zhang, R., MacDougall, A.S., Tian, D., Wang, J., & Niu, S. (2025). Wetland restoration is effective but insufficient to compensate for soil organic carbon losses from degradation. Global Ecology and Biogeography, 34: e70063.

MacDougall, A.S., Esch, E., Chen, Q., Carroll, O., Bonner, C., Ohlert, T., ... & Seabloom, E.W. (2024). Widening global variability in grassland biomass since the 1980s. Nature Ecology & Evolution, 8(10), 1877-1888.

Carroll, O., & MacDougall, A. (2024). Facilitation against herbivory more important than resource‐based niche differences for plant coexistence in a field experiment. Journal of Ecology, 112:, 1200-1209.

Kadoya, T., Nilsson, K.A., Kelly, J., Bartley, T.J.,... & MacDougall, A. S. (2024). Common processes drive metacommunity structure in freshwater fish. Global Ecology and Biogeography, 33: e13822.

• BIOL*3060 - Populations, Communities and Ecosystems (Winter 2026)
• BIOL*3130 - Conservation Biology (Winter 2026)

• Bryce Vanzant (MSc)
• John Semple (MSc)