Carissa Brown

Department of Geography
Memorial University of Newfoundland
St. John's, NL
A1B 3X9

Office: SN 2020
Tel: (709) 864-8981
Fax: (709) 864-3119



Climate and Environmental Change

I am interested in the drivers and controls of the spatial distribution of plant species, particularly trees, under climatic change. As environmental constraints on species’ distributions lessen with warming temperatures in northern ecosystems, we expect species to shift their distributions northward and upward (in alpine environments); however, a species’ establishment and persistence is controlled by many factors beyond climate, and I am particularly interested in phenomena beyond direct climate effects that drive species’ distributions.

I combine field experiments with observational studies of demographic patterns and environmental conditions across species’ ranges to test hypotheses on current constraints on the potential for future range expansion. My current research program addresses these hypotheses in three systems. 1) I am testing non-climatic constraints on tree species’ range expansion in temperate forests by reciprocally transplanting soil and seed across an elevational gradient to disentangle climatic versus substrate constraints on the distribution of sugar maple (with Mark Vellend, Université de Sherbrooke). 2) I am investigating the effects of climate-induced shifts in disturbance regimes on ecosystem structure and function in sub-arctic black spruce forests, where climate-induced shifts to the fire regime have resulted in the retraction, rather than expansion, of treeline forests (with Jill Johnstone, University of Saskatchewan). 3) I have spearheaded the Global Treeline Range Expansion Experiment (, a globally distributed experiment, to test the generality of mechanisms driving treeline. I look forward to expanding my research program to include some of the many exciting ecosystems Newfoundland and Labrador has to offer.


Post-doc (2011-13) - Université de Sherbrooke
Ph.D. (2011) - University of Saskatchewan
M.Sc. (2005) - Carleton University
H.B.Sc. (2003) - Lakehead University

Select Publications


Evans, Piers. Crofts, Anna L., and Brown, Carissa D. 2020. Biotic filtering of northern temperate tree seedling emergence in beyond-range field experiments. Ecosphere, in press.

Stralberg, D., Arseneault, D., Baltzer, J., Barber, Q., Bayne, E., Boulanger, Y., Brown, Carissa D., Cooke, H., Devito, K., Edwards, J., Estevo, C., Flynn, N., Frelich, L., Hogg, T., Johnston, M., Logan, T., Matsuoka, S., Moore, P., Morelli, T., Morissette, J., Nenzén, H., Nelson, E., Nielsen, S., Parisien, M.-A., Pedlar, J., Price, D., Schmiegelow, F., Slattery, S., Sonnentag, O., Thompson, D., Whitman, E. Climate-change refugia in boreal North America: what, where, and for how long? Frontiers in Ecology and the Environment, in press.


O’Brien, P., Vander Wal, E., Koen, E.L., Brown, Carissa D., Guy, J., van Beest, F.M., and Brook, R.K. Understanding habitat co-occurrence and the potential for competition between native mammals and invasive wild pigs at the northern edge of their range. Canadian Journal of Zoology 97: 537-546.

Mamet, S.D., Brown, Carissa D., Trant, A., and Laroque, C. Shifting global Larix distributions: Northern expansion and southern retraction as species respond to changing climate. Journal of Biogeography.

Brown, Carissa D., Dufour-Tremblay, Geneviève, Jameson, Ryan, Mamet, Steven D., Trant, Andrew, Walker, Xanthe, Boudreau, Stéphane, Harper, Karen, Henry, Greg, Hermanutz, Luise, Hofgaard, Annika, Isaeva, Ludmila, Kershaw, Peter, and Johnstone, Jill F. Reproduction as a bottleneck to treeline advance across the circumarctic forest tundra ecotone. Ecography 42: 137-147.


Frei, Esther, Bianchi, Eva, Bernareggi, Giulietta, Bebi, Peter, Dawes, Melissa A., Brown, Carissa D., Trant, Andrew, Mamet, Steven D., and Rixen, Christian. Biotic and abiotic drivers of tree seedling recruitment across an alpine treeline ecotone. Scientific Reports 8: 10894.

Evans, Piers, Davis, Emma, Gedalof, Ze'ev, and Brown, Carissa D. 2018. Small herbivore exclosure cages alter microclimate conditions. Forest Ecology and Management 415: 118-128.


Evans, Piers and Brown, Carissa D. 2017. The boreal-temperate forest ecotone response to climate change. Environmental Reviews 25: 423-431.

Vellend, M., Dornelas, M., Baeten, L., Beauséjour, R., Brown, Carissa D., De Frenne, P., Elmendorf, S.C., Gotelli, N.J., Moyes, F., Myers-Smith, I.H., Magurran, A., McGill, B.J., Shimadzu, H. & Sievers, C. 2017. Estimates of local biodiversity change over time stand up to scrutiny. Ecology 98: 583–590. doi:10.1002/ecy.1660.


Urli, M., Brown, Carissa D., Narváez Perez, R., Chagnon, P.-L. & Vellend, M. 2016. Increased seedling establishment via enemy-release at the upper elevational range limit of sugar maple. Ecology 97: 3058–3069. Commentary in Nature.


​Brown, Carissa D., Liu, J., Yan, G., and Johnstone, J.F. 2015. Disentangling legacy effects from environmental filters of post-fire assembly of boreal tree assemblages. Ecology 96: 3023-3032.


​Brown, Carissa D. and Vellend, M. 2014. Non-climatic constraints on upper elevational plant range expansion under climate change. Proceedings of the Royal Society B 281(1794): 20141779. doi:10.1098/rspb.2014.1779.

Vellend, M., Srivastava, D., Anderson, K., Brown, Carissa D., Jankowski, J., Kleynhans, E., Kraft, N., Alathea, L., MacDonald, A., Maclean, J., Myers-Smith, I., Norris, A., Xue, X. 2014. Assessing the relative importance of neutral stochasticity in ecological communities. Oikos 123(12): 1420-1430. doi:10.1111/oik.01493.

De Frenne, P., Rodriguez-Sánchez, F., Bernhardt-Römermann, M., Brown, Carissa D., Eriksson, O., Hermy, M., Mitchell, F.J.G., Petřík, P., Van Calster, H., Vellend, M., and Verheyen, K. 2014. Reply to Harwood et al.: Thermophilization estimation is robust to the scale of species distribution data. Proceedings of the National Academy of Sciences 111(13): E1166-E1166. doi:10.1073/pnas.1401414111.


​Vellend, M., Baeten, L., Myers-Smith, I.H., Elmendorf, S.C., Beauséjour, R., Brown, Carissa D., De Frenne, P., Verheyen, K., and Wipf, S. 2013. A global meta-analysis reveals no net change in local-scale plant biodiversity over time. Proceedings of the National Academy of Sciences 110(48): 19456-19459. doi:10.1073/pnas.1312779110.

De Frenne, P., Rodriguez-Sánchez, F., Coomes, D.A., Baeten, L., Verstraeten, G., Vellend, M., Bernhardt-Römermann, M., Brown, Carissa D. 2013. Microclimate moderates plant responses to macroclimate warming. Proceedings of the National Academy of Sciences 110(46): 18561-18565. doi:10.1073/pnas.1311190110.

Buma, B., Brown, Carissa D., Donato, D.C., Fontaine, J.B., Johnstone, J.F. 2013. The impacts of changing disturbance regimes on serotinous plant populations and communities. BioScience 63(11): 866-876. doi: 10.1525/bio.2013.63.11.5.

Vellend, M., Brown, Carissa D., Kharouba, H.M., McCune, J.L., and Myers-Smith, I.H. 2013. Historical ecology: Using unconventional data sources to test for impacts of global environmental change. American Journal of Botany 100(7): 1294-1305. doi: 10.3732/ajb.1200503.

Viglas, J.N., Brown, Carissa D., and Johnstone, J.F. 2013. Age and size effects on seed productivity of northern black spruce. Canadian Journal of Forest Research 43(6): 534-543. doi: 10.1139/cjfr-2013-0022.