October 2025 Science Summary

Greetings,

I've got a mixed bag of four mostly unrelated science articles this month.

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CLIMATE CHANGE:
Chen et al. 2025 reviews the evidence (from 21 studies with at least 10 years of data) that climate change may cause 3 problems (see Fig 1): mountaintop species going extinct when conditions become too warm for them, species not able to move upslope as fast as conditions change, and bottomland diversity declining b/c no warm-tolerant species can replace areas abandoned by species moving upslope. Using a model they found that mountaintop extinctions are not happening more than expected w/o climate change, many species ARE moving upslope but rarely having range contract, and only limited homogenization of bottomland species. They note including moisture changes and nitrogen deposition could have changed the results, and more research is needed to figure out why these problems are occurring in limited cases.


FOREST CARBON:
Schnabel et al 2025 has experimental evidence that after 16 years, planted forests in Panama with a mix of 5 native species sequestered 57% more aboveground carbon than monocultures. Both treatments lost soil carbon relative to the pasture they started with (see section 4.3 for possible explanations) but still gained a net of 24.7 t C / ha (90.7 t CO2e/ha) due to the aboveground gains. See  https://news.mongabay.com/2025/04/diverse-forests-and-forest-rewilding-offer-resilience-against-climate-change/ for more.


DATA AND DEFORESTATION:
Roquette et al. 2025 is ostensibly about the technical details around land use mapping in Mato Grosso, Brazil. But it actually makes a much broader point: boring things like data sources and algorithms used can have an outsize backdoor policy impact. They argue that a shift in how land use was classified could sneakily allow a ton of deforestation. Basically by changing how "forest" is defined and reclassifying some forest as a type of savanna (confusingly, cerrado is an ecosystem but the Cerrado is a biome / region), this could allow deforestation since 80% of forest has to be set aside from development but only 35% of savanna does. In some cases the new map actually does the reverse (classifying what was savanna as forest) but that can be reversed upon request. The worst case scenario is that up to 4,1 million ha could be authorized for deforestation.


MINING AND TOXICITY:
Foerster et al. 2025 found that giant otters in the Pantanal are showing evidence of mercury contamination in the Pantanal – higher when they’re closer to gold mines (except for streams close to the mine over land but not connected by water). Their results aren’t conclusive but it seems likely that the values are high enough to be causing toxicity, and that otters aren’t able to flush out the mercury by molting their fur, nor by having selenium bind to the mercury. They measured mercury in fur rather than directly in the liver, but based on other research they think it’s likely levels are high enough in some animals to cause serious toxicity and perhaps even death. 


REFERENCES:
Chen, Y.-H., Lenoir, J., & Chen, I.-C. (2025). Limited evidence for range shift–driven extinction in mountain biota. Science, 388(6748), 741–747. https://doi.org/10.1126/science.adq9512

Foerster, N., Soresini, G., Leuchtenberger, C., Bócoli, D. de A., Paiva, J. de B., Brait, C. H. H., & Mourão, G. (2025). Pervasive mercury contamination of a semi-aquatic apex predator across the Pantanal wetland. Environmental Conservation, 1–6. https://doi.org/10.1017/S0376892925100155

Roquette, J. G., Vacchiano, M. C., Daher, F. R. G., & Finger, Z. (2025). Pseudo-legal deforestation due to changes in the classification of native vegetation in Mato Grosso, Brazil. Environmental Conservation, 1–7. https://doi.org/10.1017/S037689292510012X

Schnabel, F., Guillemot, J., Barry, K. E., Brunn, M., Cesarz, S., Eisenhauer, N., Gebauer, T., Guerrero‐Ramirez, N. R., Handa, I. T., Madsen, C., Mancilla, Lady, Monteza, J., Moore, T., Oelmann, Y., Scherer‐Lorenzen, M., Schwendenmann, L., Wagner, A., Wirth, C., & Potvin, C. (2025). Tree Diversity Increases Carbon Stocks and Fluxes Above—But Not Belowground in a Tropical Forest Experiment. Global Change Biology, 31(2). https://doi.org/10.1111/gcb.70089


Sincerely,
 
Jon
 
p.s. These four foster puppies were getting some wiggles out in my yard before a "puppy party" which raises money for an animal rescue (Homeward Trails) and helps them find homes

December 2022 science summary

Happy December,

In the spirit of the paper on gratitude below: thank you all for helping me to be a better scientist and a better person. Almost every month I get a note or two from someone who found the summary useful, or who had a question / critique / idea that I learned from. That engagement has helped me push myself to keep doing these, which in terms helps me be a bit more well-read. So thank you!

Also, while they're too long to summarize briefly like I do with papers, I want to recommend the books "Think Again" by Adam Grant and "Noise" by Daniel Kahneman, Olivier Sibony, and Cass R. Sunstein. Taken together, they've given me a lot of ideas about how to get better at reevaluating my beliefs, improving how I review evidence and draw conclusions, and generate estimates. Email me if you want some notes I took on my favorite parts of each!


GRATITUDE:
As a follow-up to the Thanksgiving holiday, I wanted to share a review of a paper on gratitude by Wood et al. 2010. It's a broad review of research on the topic and fairly wonky, but I found a few things useful. I liked how table 1 lists complementary aspects of gratitude: noticing how grateful you are overall, feeling gratitude towards others, focusing on what you have (vs. what you lack), feelings of awe, expressing gratitude (internally and to others), being present, living to the fullest b/c of awareness that life is short, and feeling lucky when thinking about how things could be worse. They cover quite a lot of research on gratitude and how being more grateful is associated w/ better quality of life (although there's some question how much gratitude causes well-being vs. is just correlated). The biggest boost to feeling good came from writing a letter thanking someone and reading it to them in person, but keeping a daily diary of three things you're grateful for seems to be easier to keep up and helps you feel better for longer.


CLIMATE CHANGE
Reich et al. 2022 is an interesting experiment of how boreal forests might respond to 1.6C or 3.1C warming, using open-air heaters in an actual forest (as well as simulating reduced rainfall by covering some of the soil) to see how they respond. Conifers experienced slower growth (Fig 2) and higher mortality (Fig 1). How much varied by species, with balsam fir showing the worst impact. Compared to current conditions, warming or limited rain each reduced balsam fir growth by ~1/3, while the combination reduced growth by ~2/3. Seedling survival went down by ~40% at 1.6C, ~72% at 3.1C, and ~84% at 3.1C plus less rain. But others like jack pine had much smaller effects, and some trees like maples had similar survival rates and more growth under warming (even with less rain). So they predict that conifers will become less dominant, over the long term being replaced by deciduous trees but in the short term more likely replaced by invasive woody shrubs (since the deciduous trees aren't common enough to spread fast). There is an article about this written for general audiences at https://phys.org/news/2022-08-modest-climate-northernmost-forests.html


SUSTAINABLE RANCHING:
Santos et al. 2017 is an interesting paper on using fuzzy logic to assess beef sustainability in the Pantanal. As background - fuzzy logic doesn't mean 'sloppy reasoning' - it's actually a real thing which more or less centers on non-binary logic models. For example, old thermostats are non-fuzzy (they turn on when cold and turn off when warm enough), but newer ones are often fuzzy (adjusting fan speed, turning auxiliary heat on or off, etc. depending on performance). In this case, they take a ton of practical indicators, map each onto a 4 point scale, and combine them into a single "overall sustainability index" (see Figure 1). Check out Appendix I for the list of how well each indicator matched expert judgments.


OTTERS:
Valladares et al. 2022 used drones to figure out what kind of habitat giant otters in Peru most preferred. They found giant otters preferred oxbow lakes with the largest water surface area, the least floating vegetation (more open water), and more dense forest canopy cover along the banks of the lakes.

REFERENCES:
Reich, P. B., Bermudez, R., Montgomery, R. A., Rich, R. L., Rice, K. E., Hobbie, S. E., & Stefanski, A. (2022). Even modest climate change may lead to major transitions in boreal forests. Nature, 608(7923), 540–545. https://doi.org/10.1038/s41586-022-05076-3

Santos, S. A., de Lima, H. P., Massruhá, S. M. F. S., de Abreu, U. G. P., Tomás, W. M., Salis, S. M., Cardoso, E. L., de Oliveira, M. D., Soares, M. T. S., dos Santos, A., de Oliveira, L. O. F., Calheiros, D. F., Crispim, S. M. A., Soriano, B. M. A., Amâncio, C. O. G., Nunes, A. P., & Pellegrin, L. A. (2017). A fuzzy logic-based tool to assess beef cattle ranching sustainability in complex environmental systems. Journal of Environmental Management, 198, 95–106. https://doi.org/10.1016/j.jenvman.2017.04.076

Valladares, N. A., Pardo, A. A., Chiaverini, L., Groenendijk, J., Harrington, L. A., Macdonald, D. W., Swaisgood, R. R., & Barocas, A. (2022). High‐resolution drone imagery reveals drivers of fine‐scale giant otter habitat selection in the land‐water interface. Conservation Science and Practice, December 2021, 1–14. https://doi.org/10.1111/csp2.12786

Wood, A. M., Froh, J. J., & Geraghty, A. W. A. (2010). Gratitude and well-being: A review and theoretical integration. Clinical Psychology Review, 30(7), 890–905. https://doi.org/10.1016/j.cpr.2010.03.005


Sincerely,
 
Jon