- Prickly prospects for cacti under climate change
In 2017, I started working with Dr. Brian Enquist at The University of Arizona on range modeling of
cacti under climate change. While many associate cacti with deserts, this family of plants ranges from Canada to the southernmost reaches of South America. Given their drought resistance, the public
tends to think of cacti as very resilient, but it is in fact one of the most threatened plant groups on earth. We use tens of thousands of geographic observations from the BIEN network
to model the potential future impacts of climate change on hundreds of species of cactus. Results indicate that more than half of all cactus species may undergo range contractions in this century.
We are currently working on expanding the taxonomic scope of these results, while integrating forecasts of droughts events.
Publication:
- Pillet, M., Goettsch, B., Merow, C., Maitner, B., Feng, X., Roehrdanz, P. R., Enquist, B. J., 2022. Elevated extinction risk of cacti under climate change. Nature Plants. doi:10.1038/s41477-022-01130-0
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- Drivers of extinction risk for the Chilean cactus genus Copiapoa
Machine learning models were used to assess the drivers of extinction risk for the Chilean cactus genus Copiapoa. This genus is considered very threatened, with 92% of species classified as Critically Endangered, Endangered, or Vulnerable using IUCN Red List criteria.
Analyses indicate that trade, poaching, and habitat degradation are the main drivers of threatened status in this genus.
Publication:
- Villalobo-Lopez, A., Pena, C.M., Varas-Myrik, A., Pillet, M., Jahnsen, P., Pliscoff, P., Goettsch, B., Guerrero, P.C., 2024. Effects of trade and poaching pressure on extinction risk for cacti in the Atacama Desert. Conservation Biology. doi:10.1111/cobi.14353
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- Maintaining collections data in horticulture
Plants in the horticultural trade can be of immense conservation value, yet metadata for such plants are rarely maintained. In this article, Tristan Davis and I lay out some best practices to encourage horticulturalists to manage collections data.
Publication:
- Davis, T. and Pillet, M., 2023. Don't tell, show me: the importance of maintaining data in cultivated plants. Cactus and Succulent Journal. doi:10.2985/015.095.0313
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- Demographic range modeling of Pinus edulis
From 2016 to 2018, I worked with Dr. Margaret Evans at The University of Arizona on demographic
range modeling of pinyon pine. Pinyon pine is an important tree species of the pinyon-juniper woodlands of the American Southwest that has been undergoing mass mortality events
due to elevated temperatures, prolonged droughts, and bark beetle outbreaks. Many of the threats faced by pinyon pine are expected to become more severe with ongoing climate change.
Understanding the future of species under climate change requires a thorough understanding of species' niches, and thus their demographic responses to the environment. Using a
type of size-structured demographic modeling technique, Integral Projection Modeling, spatially-explicit maps of predicted population growth rate across
pinyon pine's range were produced. Climate alone is insufficient to explain the distribution of pinyon pine, complicating predictions of its future.
Publication:
- Schultz, E., Hulsmann, L., Pillet, M. D., Hartig, F., Breshears, D. D., Record, S., Shaw, J. D., DeRose, R. J., Zuidema, P. A., Evans, M. E. K., 2021. Climate-driven, but dynamic and complex? A reconciliation of competing hypotheses for species' distributions. Ecology Letters. doi:10.1111/ele.13902
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- Competition and mortality of trees in tropical forests
From 2015 to 2016 I worked with Dr. Ben Poulter at Montana State University on tropical forest ecology.
A first project focused on the role of competition in driving mortality of tropical trees. We found strong evidence for self-thinning at the scale of entire forest stands,
within stands, and individual trees. Classification accuracy of individual tree mortality models was strongly improved by including local tree density as a predictor.
A second project showed the potential improvements of predicting forest carbon stocks and dynamics by integrating remotely-sensed data, ground inventory data and the dynamic
global vegetation model ORCHIDEE.
Publications:
- Pillet, M., Joetzjer, E., Belmin, C., Chave, J., Ciais, P., Dourdain, A., Evans, M., Herault, B., Luyssaert, S., Poulter, B., 2017. Disentangling competitive versus climatic effects on tropical forest mortality. Journal of Ecology. doi:10.1111/1365-2745.12876
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- Joetzjer, E., Pillet, M., Ciais, P., Chave, J., Schlund, M., Maignan, F., Barichivich, J., Luyssaert, S., Herault, B., von Poncet, F., Poulter, B., 2017. Assimilating satellite-based canopy height within an ecosystem model to estimate aboveground forest biomass. Geophysical Research Letters. doi:10.1002/2017GL074150
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- The future of Pinus albicaulis under climate change
In 2014, I worked with Dr. Andy Hansen at Montana State University on the future of whitebark pine. While
multiple stressors, including climate change, pine bark beetle, and blister rust, are simultaneously threatening the future of this subalpine tree species of the Rocky Mountains,
we propose several scenarios under which whitebark pine may persist on the landscape.
Publication:
- Hansen, A., Ireland, K., Legg, K., Keane, R., Barge, E., Jenkins, M., Pillet, M., 2016. Complex challenges of maintaining whitebark pine in Greater Yellowstone under climate change: A call for innovative research, management, and policy approaches. Forests 7, 54.
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