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Victor Van der Meersch

@vvandermeersch.bsky.social
1.2K followers 615 following 35 posts

Postdoc in Lizzie Wolkovich lab at UBC, Vancouver. European citizen 🇪🇺 (Not giving up the em dash just because ChatGPT uses it) #globalchangecology #forest #modeling

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Victor Van der Meersch @vvandermeersch.bsky.social · 21/08/2026
A good game, but no Rhat trick
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Victor Van der Meersch @vvandermeersch.bsky.social · 20/08/2026
Had a wonderful time at StanCon in Uppsala! Glad to connect with such a thriving Bayesian community. Many thanks to the organizers for putting together this cool event
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Reposted by Victor Van der Meersch
Michael "Shapes Dude" Betancourt @betanalpha.bsky.social · 18/06/2026
Is this a joke? Yes. Is it also an opportunity to demonstrate how extrapolations that incorporate uncertainty are far better behaved than those that don't? Absolutely.
Posterior predictions that extrapolate Messi's goals per game to the 2042 world cup using an extremely simple model of scoring rate evolution.
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Reposted by Victor Van der Meersch
Andrew Gelman et al. @statmodeling.bsky.social · 29/05/2026
15 new articles on statistical workflow! statmodeling.stat.columbia.edu/2026/05/29/1...
statmodeling.stat.columbia.edu
15 new articles on statistical workflow! | Statistical Modeling, Causal Inference, and Social Science
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Reposted by Victor Van der Meersch
lizzieinvancouver.bsky.social @lizzieinvancouver.bsky.social · 16/05/2026
Spent a lucky last few days trying to model how trees grow ... What to do when a hierarchical GP is not enough for all the behaviours?
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Victor Van der Meersch @vvandermeersch.bsky.social · 22/10/2025
Great week in New York with @lizzieinvancouver.bsky.social! We had inspiring discussions with @betanalpha.bsky.social and @dustybowl.bsky.social on tree growth modeling. Thanks for sharing so many ideas. Excited to move this project forward!
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Reposted by Victor Van der Meersch
Temporal Ecology Lab @temporalecology.bsky.social · 06/10/2025
Our department at UBC is hiring for a professor of forest ecophysiology, including "tree ecophysiology; plant abiotic or biotic stress physiology; forest mortality and climate change responses; forest carbon balance; tree water relations; or nutrient use." Learn more at: tinyurl.com/5da56f5c
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Victor Van der Meersch @vvandermeersch.bsky.social · 31/07/2025
Working with @lizzieinvancouver.bsky.social is not just about doing cool science, it’s also about mind-blowing cultural discoveries like Jiffy Pop (for a European like me) 📷 @christopherd98.bsky.social @temporalecology.bsky.social
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Reposted by Victor Van der Meersch
Michael "Shapes Dude" Betancourt @betanalpha.bsky.social · 11/07/2025
Did you hear that I'll be teaching four brand new remote courses this year covering Bayesian mixture modeling, survival modeling, pairwise comparison modeling, and ordinal modeling, www.eventzilla.net/e/advanced-b...? Reskeets and sharing with your friends and colleges appreciated!
eventzilla.net
Advanced Bayesian Modeling In Stan
Despite the promise of big data, inferences are often limited not by the size of data but rather by…
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Reposted by Victor Van der Meersch
lizzieinvancouver.bsky.social @lizzieinvancouver.bsky.social · 07/07/2025
Thanks to @betanalpha.bsky.social @vvandermeersch.bsky.social and Janneke Hille Ris Lambers for a fun day discussing how trees grow at Mount Rainier in Mount Rainier NP to round out June! And to all of them plus Mao and Avery for more math at UW (see gcecology.tumblr.com/post/7877335...).
Smiley people in carMount Rainier entrance (Ashford)
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Reposted by Victor Van der Meersch
Proceedings of the National Academy of Sciences @pnas.org · 17/06/2025
The summer solstice may signal peak growth for many plants. On average, the summer solstice coincides with a thermal optimum during the growing season. As the climate warms, this cue could remain stable, but there’s significant local variation. In PNAS: www.pnas.org/doi/10.1073/...
A blooming field of sunflowers. Stock photo.
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Victor Van der Meersch @vvandermeersch.bsky.social · 12/06/2025
👉 Our findings highlight how hard it is to separate the effects of photoperiod from those of a thermal optimum cue. Much remains to be done to unravel the complexity of phenological cues, and understand the implications for forecasting plant responses to climate change!
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Victor Van der Meersch @vvandermeersch.bsky.social · 12/06/2025
💡 As we only used temperature data (and not photoperiod), this could suggest that plants rely on plastic thermal cues rather than a fixed photoperiod switch, such as the solstice.
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Victor Van der Meersch @vvandermeersch.bsky.social · 12/06/2025
🔎 But when we zoomed-in, we found significant local variation. Some sites had an optimum >20 days before sites, while other sites, especially in Scandinavia, had an optimum >20 days after solstice.
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Victor Van der Meersch @vvandermeersch.bsky.social · 12/06/2025
🌍 Using climate data from the past, present, and future, we found that the summer solstice tends to align with a thermal optimum during the growing season. The period around the solstice represents on average a good trade-off between environmental predictability and growth potential.
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Victor Van der Meersch @vvandermeersch.bsky.social · 12/06/2025
Several recent studies suggest the summer solstice might act as a universal cue for key plant processes. But why would the longest day of the year be so important? Our new study in @pnas.org sheds some light on this question ⏬ www.pnas.org/doi/10.1073/... @lizzieinvancouver.bsky.social
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Victor Van der Meersch @vvandermeersch.bsky.social · 11/06/2025
New PhD position in the Temporal Ecology Lab (UBC, Vancouver)! 🌲 The student will investigate how seed and seedling pathogens influence forest regeneration and diversity, in collaboration with the Plant Ecology Group at ETHZ. Please find more information here: temporalecology.org/wp-content/u...
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Reposted by Victor Van der Meersch
PLOS Climate @plosclimate.org · 22/05/2025
New research by Wolkovich and colleagues highlights spatial and temporal complexities in the impacts of climate change on wine grapes around the world journals.plos.org/climate/arti... @vvandermeersch.bsky.social @dustybowl.bsky.social Photo: Marc Benedetti, Pixabay
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Victor Van der Meersch @vvandermeersch.bsky.social · 08/05/2025
💡 Takeaway? Don’t blindly trust good model fit! Always look into the biological processes, and use inverse calibration carefully. This is critical if we want to preserve the value of process-based models over less mechanistic approaches.
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Victor Van der Meersch @vvandermeersch.bsky.social · 08/05/2025
Inverse calibration with distribution data should be applied selectively, to calibrate parameters where we lack other sources of data.
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Victor Van der Meersch @vvandermeersch.bsky.social · 08/05/2025
⚠️ Compensation between processes leads to non-identifiability: different parameter sets can produce similar species distributions, but with different internal dynamics.
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Victor Van der Meersch @vvandermeersch.bsky.social · 08/05/2025
Inverse calibration can yield good predictions of species ranges—even under past climates. But it might do so for the wrong reasons.
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Victor Van der Meersch @vvandermeersch.bsky.social · 08/05/2025
How can we spread the use of process-based models in ecology? They are powerful but require a lot of data. Inverse calibration offers a shortcut—adjusting parameters using species distribution data. But do we still get biologically realistic results? ⏬ www.sciencedirect.com/science/arti...
sciencedirect.com
Can inverse calibration help improving process-explicit species distribution models?
Process-explicit models (PEMs) are expected to provide reliable projections of species range shifts because they explicitly model the biological mecha…
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Victor Van der Meersch @vvandermeersch.bsky.social · 08/05/2025
💡 Takeaway? Don’t blindly trust good model fit! Always look into the biological processes, and use inverse calibration carefully. This is critical if we want to preserve the value of process-based models over less mechanistic approaches.
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Victor Van der Meersch @vvandermeersch.bsky.social · 08/05/2025
⚠️ Compensation between processes leads to non-identifiability: different parameter sets can produce similar species distributions, but with different internal dynamics.
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Victor Van der Meersch @vvandermeersch.bsky.social · 08/05/2025
Inverse calibration can yield good predictions of species ranges—even under past climates. But it might do so for the wrong reasons.
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Victor Van der Meersch @vvandermeersch.bsky.social · 28/03/2025
📄 For French speakers passing by, or those who want to work on their French, a short analysis of my PhD thesis has been published on the website of the Academy of Agriculture (and forests?). You can find it here (en français, donc): www.academie-agriculture.fr/publications...
academie-agriculture.fr
Analyses de thèse | Académie d'Agriculture de France
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Victor Van der Meersch @vvandermeersch.bsky.social · 07/03/2025
(Thanks to all the collaborators, including @fredsaltre.bsky.social !)
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Victor Van der Meersch @vvandermeersch.bsky.social · 07/03/2025
💡 The challenge ahead: finding the right balance between representing complex biological processes, diverse data sources to support them, and robust inference methods!
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Victor Van der Meersch @vvandermeersch.bsky.social · 07/03/2025
⚠️ That said, more complexity isn't always better. More processes involve additional parameters, which are usually harder to calibrate. And we still often rely on a single parameter set per species — neglecting to quantify and propagate uncertainty when making projections
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Victor Van der Meersch @vvandermeersch.bsky.social · 07/03/2025
⚙️ Beyond these findings, process-based models are an important tool to encourage a comprehensive and continuous incorporation of scientific knowledge and experimental data
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Victor Van der Meersch @vvandermeersch.bsky.social · 07/03/2025
👀 Yet, the conditions during the Early Holocene were different from the conditions that are expected in coming decades, and one would need to go back much further in time to find analog conditions to our future climate
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Victor Van der Meersch @vvandermeersch.bsky.social · 07/03/2025
❔ Why does this matter? Given the projected pace of climate change, our results challenge the heavy reliance on SDMs for forest management, conservation planing and biodiversity forecasting
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Victor Van der Meersch @vvandermeersch.bsky.social · 07/03/2025
👉 We found that process-based models — which explicitly translate our knowledge of species functioning into equations — may outperform classical SDMs in novel climates (that is, beyond current climatic conditions)
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Victor Van der Meersch @vvandermeersch.bsky.social · 07/03/2025
🌍 To do this, we used 12,000 years of pollen data from Europe. This period, and especially the Early Holocene, provides a great way to challenge our models with rapidly changing climatic conditions
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Victor Van der Meersch @vvandermeersch.bsky.social · 07/03/2025
Ever wondered how reliable species distribution models (SDMs) are in the face of climate change compared to more mechanistic approaches? We did too, and our results are now published in Ecology Letters ⏬ onlinelibrary.wiley.com/doi/10.1111/...
onlinelibrary.wiley.com
Paleorecords Reveal Biological Mechanisms Crucial for Reliable Species Range Shift Projections Amid Rapid Climate Change
Climate change has created an urgent need for reliable projections of species distributions. By hindcasting forest tree range shifts across Europe over the last 12,000 years, we show that process-exp...
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Reposted by Victor Van der Meersch
Rupert Seidl @rupertseidl.bsky.social · 24/02/2025
Interesting work by van der Meersch et al. out in Ecology Letters, nicely illustrating that process-based models are more robust than correlative models for predicting species distributions under novel climatic conditions doi.org/10.1111/ele....
doi.org
Paleorecords Reveal Biological Mechanisms Crucial for Reliable Species Range Shift Projections Amid Rapid Climate Change
Climate change has created an urgent need for reliable projections of species distributions. By hindcasting forest tree range shifts across Europe over the last 12,000 years, we show that process-exp...
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Victor Van der Meersch @vvandermeersch.bsky.social · 17/01/2025
I'd love to join, thank you!
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Victor Van der Meersch @vvandermeersch.bsky.social · 05/12/2024
Congrats Anne! 🌲🌳
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Victor Van der Meersch @vvandermeersch.bsky.social · 03/12/2024
Hi Dan! Would love to be added if possible, thanks!
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Victor Van der Meersch @vvandermeersch.bsky.social · 01/12/2024
Hi Jonathan! Would love to be added please
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Victor Van der Meersch @vvandermeersch.bsky.social · 01/12/2024
Would love to be added if there's still some room! Thanks
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Victor Van der Meersch @vvandermeersch.bsky.social · 26/11/2024
Hi Ben! Would love to be added, please (and thanks for the starter pack)
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Victor Van der Meersch @vvandermeersch.bsky.social · 26/11/2024
Hi Kevin! Thanks for this starter pack. Would love to be added if possible
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