Best of 2024 science summaries

Happy New Year,

How better to celebrate the new year than with old science?!

As usual, here are my favorite 15 reruns (article summaries) from 2024, plus a few of my favorite bits about AI since I keep getting requests for more of that:

• Don’t put anything sensitive into AI! Enterprise licenses provide some protection for non-public but not highly sensitive info.
• I loved these tips for better AI prompts to help you get better results: https://www.oneusefulthing.org/p/getting-started-with-ai-good-enough  
• This is a great overview of some really good and really bad use cases for AI: https://www.oneusefulthing.org/p/15-times-to-use-ai-and-5-not-to
• Remember that AI is always changing. As of mid-December, Google Gemini’s NotebookLM not only turns a PDF you upload into an NPR-style podcast, it also now lets you interact w/ the “hosts”!  

Upset at the articles I missed? Please email me your own favorites from 2024 and I'll do what I can to include them in upcoming summaries.

As always people can sign up to receive these summaries at http://bit.ly/sciencejon (no need to email me). On with the reruns!


CLIMATE CHANGE
OK, for years people have been hyping the potential of a kind of seaweed (Asparagopsis) to reduce methane emissions in cattle. But the in vitro evidence was mixed - with potential toxicity and downsides a concern if the dose wasn't just right. George et al 2024 is a live trial with good news! They found methane emissions from cattle given an Asparagopsis additive were cut roughly in half compared to control, with 6.6% higher weight gain per unit of feed and no substantial impacts on quality or health (fat color maybe a bit better, tenderness maybe a bit worse). The methane reduction peaked at day 21 and declined afterwards, but since most cattle are in feedlots only ~3 months (ranging from 1.5-4) the decline after day 100 is pretty moot. That's a lot of potential! The only potential downsides were ~50% higher bromine residues in kidney and muscle (I couldn't quickly find guidance on safe levels). Caveats: 1) there were no conflicts declared but the authors appear to almost all work as feedlot consultants and it's single rather than double-blinded, 2) in the US the feedlot phase is only about 15% of the lifecycle emissions of a cow (and of that, some is from growing crops and nitrous oxide) so TOTAL impact on CO2e / kg beef is not as dramatic. Overall my take is 1) this should absolutely be tested and replicated more - anything that reduces the very high carbon of beef is worth pursuing. BUT 2) if this is marketed as "green beef" or license to avoid reductions, it could be net harmful for the climate. and 3) IF spraying this solution on grass worked similarly and didn't inhibit development of calves, the impact could be much higher (since ~80%ish of a cow's life is grazing prior to feedlot, and methane emissions are higher on grass than feed). So let's test that too (note: there’s a new study claiming a ~1/3 reduction in methane during grazing via seaweed supplements that I haven’t reviewed yet). There's a blog about this at https://www.theguardian.com/australia-news/article/2024/aug/18/feeding-seaweed-supplement-to-cattle-halved-methane-emissions-in-australian-feedlot-study-finds

Trencher et al, 2024 is an analysis of the quality of carbon credits on the voluntary market. They focus on the 20 companies retiring the most credits between 2020-2023 (134 million metric tons CO2e), which is 20% of all global retirements on the three registries (see Fig 1 for company list). They found 87% of credits have a high risk of not providing real additional reductions (6% were low risk, most of the rest was medium), and 97% of credits focused on avoiding emissions rather than removal. Note that they classified all REDD+ (reducing deforestation and/or degradation) as high risk given that they have often 1) overestimated additionality, 2) not stopped deforestation, and/or 3) displaced deforestation elsewhere (aka 'leakage'). They also classify large-scale renewable energy as high-risk, since the price of credits is not typically the decisive factor in those projects (they are often built w/ or w/o credits) and they are often build in countries w strong government support for renewable energy. They also found that companies strongly prefer the cheapest credits (which creates demand for lower-quality offsets) often from older projects, although some companies have paid a lot more for REDD projects. The authors call for more regulation of the voluntary market, and for companies not using voluntary credits to support claims of offsetting emissions.

 
CONSERVATION IMPACT:
Langhammer et al. 2024 is the big splashy new Science paper looking at the global impact of conservation. It's a meta-analysis of trials comparing interventions to counterfactuals (similar areas w/o action). They found conservation helps 2/3 of the time (45% of trials led to absolute improvement in biodiversity, 21% reduced biodiversity loss), but is harmful 1/3 of the time (in 21% of trials biodiversity declined more due to conservation, in 12% it improved less due to conservation), and only 2% of trials showed no difference). That's not a great track record - I'd hoped net harm would be rare (1/3 is very high!), and just over half the time we're losing biodiversity despite trying to stop it. Fig 2 helpfully shows how impact varies by type of intervention: protected areas show the smallest positive effect on average, and invasive species removal shows the largest positive effect. I'd ignore "sustainable use of species" b/c it's a weirdly broad category that somehow only included 4 papers on wildlife hunting and 1 on fishing, although a few fishing papers are included under protected areas (details in the supplement - this makes me think their sample is not representative of conservation broadly). While the authors conclude conservation is working and we should do more of it, I bet if this was a paper on medical efficacy we'd consider interventions that are 2/3 helpful and 1/3 harmful an urgent cry to improve efficacy BEFORE we try to scale work that is so often ineffective or harmful. Would you send your kids to a school where 1/3 of students learned less than kids not in school at all?


EVIDENCE ASSESSMENTS / SCIENTIFIC REPRODUCIBILITY:
Scientists often complain policy makers don't follow our recommendations (or even read them). But Brisco et al. 2023 finds that recommendations from meta-analyses tend to change over time as research continues. They looked at 79 papers (121 meta-analyses) and found that over time 93% of analyses either had a big change in effect size (+- 50% or more, see Fig 2 for examples) or change in statistical significance (see Fig 3). The key results are in Fig 5, which I find pretty confusing. Results staying consistently statistically significant w/ each study is rare, and ~25% of analyses showed a reversal in effect (from positive to negative or vice versa). Those reversals are the change we care the most about since it means action can backfire. BUT if you ignore the studies that were never statistically significant (seems safe) it's only 12% of analyses that flip, and if you also ignore the ones that lost significance (meaning the reversal is less meaningful) it goes down to 11%. That's still pretty bad though - 1 time out of 9 the scientific recommendation might lead to the opposite outcome we intend. They recommend scientists use cumulative meta-analyses to look for trends, and the reminder that we're often wrong reinforces the need for adaptive management and an empirical approach to seeing what works in a given context.
 
 
FIRE:
Pivello et al. 2021 is a good comprehensive overview of wildfire across Brazil. It's long and dense so hard to summarize! Natural fires are most common at the beginning of the wet season when lightning ignites accumulated dry vegetation. Fig 1 has an overview of fire by biome: the Amazon followed by Cerrado have the most fires; the Pantanal and Cerrado typically have the highest % burned (they are both fire-dependent, as is the Pampas, see Fig 2), and in 2020 the Pantanal had roughly triple the % burned and fire density as others. Pollen evidence (from a different study, Power et al. 2016) indicates fire activity in the Pantanal peaked about 12,000 years ago (people have only lived there for about 8,000 years, and grazed cattle for ~250). Introducing cattle has caused a shift from burning every 3-6 years (mostly in the beginning or sometimes end of the wet season) to burning every year or two during a relatively dry part of the wet season (see Fig 6). Conversely, fire suppression in the Cerrado has also driven woody encroachment of savannas. In the Amazon and Atlantic Forest, natural fire is rare and very infrequent, making fire especially harmful as species are not adapted to it. The combination of deforestation and drought make it much easier for fire to spread (and Amazonian deforestation means more drought in the Pantanal). 1/3 of the forest in the Amazon from 2003-2019 were associated w/ deforestation. Indigenous people mostly used fires in small areas, but since European colonization it's used at larger scales to clear land permanently (or alternately suppressed, see Fig 7 for a nice timeline of fire landmarks). Integrated fire management (IFM) is uncommon (except a few federal protected areas, mostly in the Cerrado). Only Minas Gerais and Roraima states have IFM laws. The authors recommend: 1) fire management policy should include climate mitigation and poverty reduction to reduce fire risk; 2) better fire monitoring and management systems; 3) filling knowledge gaps around drivers of fire, how fire impacts wetlands, human dimensions of fire, impacts of different fire regimes on grazing productivity and carbon; 4) better enforcement of illegal fire use (including more resources); 5) including local communities in developing fire management plans, and 6) national and state level fire policies with adequate resources for implementation (including data collection and sharing, and clear and simple rules about fire use).
 
Balch et al. 2024 found that over the last 20 years fires in the US have been spreading faster. In the Western US over 20 years the average peak daily growth rate (the average of the fastest each fire grew on a given day) increased 2.5 times (in California they increased by 4 times). The fastest 3% of fires nationally (spreading more than 1,620 ha in a day) destroyed between 78-89% of the buildings lost to fire (the paper lists each number in different section for the same stat). I’ve heard a lot more about severity and frequency and extent of fire, but thinking about speed is also important as faster fires are harder to respond do, and may make really smooth coordination increasingly important. Increases in drought conditions and potential increases in high winds could make this worse over time. 


FRESHWATER:
Flitcroft et al. 2023 notes that counting effective freshwater protection globally is really hard (as is getting effective protection to happen). Fig 1 has a nice summary of how restrictive different protection mechanisms are. They also call for both better management of existing protected areas (PAs) to include freshwater conservation needs, and protections for freshwater in new places. While issues around data resolution and data availability continue to pose challenges to freshwater conservation, they argue that more explicit consideration of both freshwater and terrestrial objectives in any area-based protection is a good start.
 
Jasechko et al. 2024 is a global assessment of groundwater levels since 2000 (using 170,000 wells and 1,700 aquifers) and comparing them to earlier trends for ~1/3 of those aquifers. They found 36% of aquifers were drying up (water level dropping deeper by 0.1 m / yr or more), and 6% of aquifers were improving (water level rising 0.1 m / yr or more), w/ 58% of aquifers not changing quickly in this century. 30% of the aquifers where they had 40 years of data declined faster in the 21st century than the 20 years prior (see Fig 3), but in 49% of those aquifers declines slowed or reversed. Unsurprisingly the trend is worst in drylands w/ farmland, and groundwater deepening is globally correlated w/ low precipitation, high evapotranspiration, and extent of agriculture. See Fig 1 and 2 for global map of trends, highlighting hotspots of decline in CA, the US high plains, Iran, India, central Chile, and a few others. There's a news article about the study at https://www.cnn.com/2024/01/24/climate/groundwater-global-study-scn/index.html

Wang et al. 2024 looks at how climate change has changed the seasonality of river flow (how much it varies month to month, including frequency of droughts and floods). They found that ~14% of long-term river gauges show changes in seasonality over the last 50 years that isn't driven by changing annual precipitation. The surprise is that seasonality is mostly DECREASING counter to the narrative of more floods and droughts (see Fig 1 for a map of results, and Fig 2 which adds detail). In their figures brown means less seasonality (more even flow): "L+" means low flows become higher flows (NOT higher frequency of drought) while "H-" means floods see lower flood volume (again NOT lower frequency of flood events). You'll see most of North America, most of Europe, and some of Russia have seen reduced seasonality in recent decades. Blue means MORE seasonality, focused in: SE Brazil, some European countries, and in the US the SE and some of the Rocky Mountains. The explanation is worth reading in full, but in brief: 1) snow melting earlier means less runoff from snow at the same time as spring rains, 2) early spring greening means more water gets transpired, 3) it's more complicated in places not dominated by snowmelt.
 

HORIZON SCANNING / EMERGING ISSUES:
I realized I've only rarely reviewed Bill Sutherland's annual "horizon scan" article listing 15 emerging conservation issues that potentially deserve to be better-known. Last year (I just read the 2024 version a year late) they used artificial intelligence to generate some of the ideas but none made the cut. Here's the final list so you can decide if any are worth looking up (and here’s the brand new 2025 paper if you want to catch up):
1. New sources of hydrogen for energy (mining or electrolysis instead of natural gas),
2. Decarbonized ammonia (making fertilizer w/ lower carbon emissions but could increase fertilizer wasted),
3. Feeding people and/or animals w/ cultivated bacteria,
4. Light-free artificial photosynthesis (yes, it's as weird as it sounds) for indoor ag,
5. Enhanced rock weathering at scale (putting rock dust on croplands to sequester carbon),
6. Potential global declines in earthworm populations (more data is needed to see if UK decline is representative),
7. Ecoacoustics to monitor soil ecology (testing how meaningful soil sounds are for estimating things like biodiversity and water flow),
8. Wildfire affecting El Niño and La Niña phase (aerosols leading to the La Niña phase),
9. Benchtop DNA printers (potential to eventually allow guerilla genetic engineering),
10. Better predicting chemical toxicity from early data,
11. a skyscraper city planned in Saudi Arabia that birds could crash into when migrating from Europe to Africa.,
12. Sea urchin die-offs (possibly from disease) leading to algal overgrowth on corals and other marine ecosystems,
13. Ocean-based carbon removal (from the air or dissolved in water to stable forms),
14. Warming "twilight zones" (200-1000m below sea surface) affecting global nutrient and carbon cycles, and
15. Melting Antarctic ice changing deep sea currents.


MAMMALS:
Greenspoon et. al 2023 is an attempt to estimate the biomass of all wild mammals on earth (combined), arriving at 60 Mt total: 20 Mt (million metric tons) on land (half from "even-hoofed" mammals, see FIg 2), and 40 Mt in oceans (23 Mt of which comes from baleen whales). But the kicker is that they estimate human biomass at 390 Mt, and livestock biomass at 630 Mt (420 Mt from cattle: which is more than all humans plus all wild land mammals). Fig 4 awkwardly tries to compare all mammal biomass on earth, showing how wild species have been squeezed. The wild mammal estimates mostly come from the IUCN red list which skews towards expert assessments of more threatened spp., and the numbers won't be "right" for several reasons (these estimates are hard, and the data are highly limiting). But it seems solid that humans and livestock substantially outweigh wild mammals.
There's a good critique of the paper (arguing that Greenspoon et al. underestimate biomass by a factor of 5.5) by Santini et al. here https://www.pnas.org/doi/10.1073/pnas.2308958121 and a reply from the Greenspoon authors pointing out why the methods used in the critique are also (differently) flawed: https://www.pnas.org/doi/10.1073/pnas.2316314121
 

MIGRATORY SPECIES / WILDLIFE CONNECTIVITY:
The new State of the World's Migratory Species report (UNEP-WCMC 2024) has an update on how the 1,189 migratory species in CMS are doing. Almost half (44%) are in decline (with 22% at risk of extinction, including 97% of listed fish spp), 1/3 are stable, and the rest are split between improving and unknown. The report also notes that 399 spp not even listed in CMS (including ~200 fish spp, ~150 bird spp, and ) are at risk (from critically endangered to near threatened). See Fig 2.10b for an overview of which migratory species CMS leaves out (including horseshoe crabs!) and 2.10c for the subset at risk. Unsurprisingly the main threats are habitat loss (along w/ degradation and fragmentation) and overexploitation (hunting and fishing). Recommendations on page ix-xi are familiar and unsurprising (albeit important). There's a blog about this paper with key highlights at: https://www.unep.org/news-and-stories/press-release/landmark-un-report-worlds-migratory-species-animals-are-decline-and
 
Littlefield et al. 2024 (I'm a minor author) examines how wildlife road crossings can be beneficial to help species adapt to climate change. We recommend that when siting crossings we should consider a) current wildlife movements, AND expected short-term and long-term shifts in species range and migrations due to b) climate change AND c) human land use change (expansion of housing, ag, etc.). We show how doing this was accomplished for elk in Colorado.
For this to work well, diversion fencing is important to channel wildlife to crossings, and avoiding future fragmentation is key. The paper is open access. There's a press release for the paper here: https://fish.freeshell.org/publications/Littlefield2024-PressRelease.pdf


POLLINATORS:
Li et al. 2024 is a methods paper about using land cover data to predict floral resource availability for pollinators. I'm an author despite minimal input; the lead author based this on work by the last author, who I provided some guidance to when he was a postdoc. There are a few potentially interesting things in here. 1) Most pollinators don't make much honey, so their populations are limited by the time of year w/ the least food available (pollen and nectar). The methods here help you figure out those bottlenecks if you want to target habitat restoration to boost pollinator populations. 2) Plants vary a lot in how much nectar and pollen they make. Not every crop makes flowers that feed pollinators (likely obvious, but some crops and cover crops are harvested or terminated before flowering, and wind-pollinated plants don't have nectar). Trees produce a ton of nectar and pollen. 3) The paper looked at two different ways to map land cover, and surprisingly the simpler approach worked as well (similar error levels)! It's a good reminder to always question whether you need more complexity and accuracy. If you just have a garden and want more bees and other pollinators, this blog post I wrote may help: https://sciencejon.blogspot.com/2024/05/new-paper-on-mapping-pollinator.html
 

WETLANDS:
The latest report on the status of wetlands in the US (excluding AK and HI) is a bummer but has some useful info. Key summaries are in Fig 9 and Table 2, but in short on net 221,000 acres of wetlands were converted, mostly to ag and tree plantations followed by housing developments. But that net change hides that fact that we actually lost 670,000 acres of vegetated wetlands, with non-vegetated wetlands like ponds, sandbars, and mudflats increasing (but NOT providing nearly as much ecological value). The report calls for more coordination to achieve no net loss of wetlands, to update and improve the National Wetlands Inventory, develop and implement better wetland conservation and management (duh), and commit to long-term monitoring and adaptive management.


REFERENCES:

Balch, J. K., Iglesias, V., Mahood, A. L., Cook, M. C., Amaral, C., DeCastro, A., Leyk, S., McIntosh, T. L., Nagy, R. C., St. Denis, L., Tuff, T., Verleye, E., Williams, A. P., & Kolden, C. A. (2024). The fastest-growing and most destructive fires in the US (2001 to 2020). Science, 386(6720), 425–431. https://doi.org/10.1126/science.adk5737
 
Brisco, E., Kulinskaya, E., & Koricheva, J. (2023). Assessment of temporal instability in the applied ecology and conservation evidence base. Research Synthesis Methods, November, 1–15. https://doi.org/10.1002/jrsm.1691
 
Flitcroft, R. L., Abell, R., Harrison, I., Arismendi, I., & Penaluna, B. E. (2023). Making global targets local for freshwater protection. Nature Sustainability. https://doi.org/10.1038/s41893-023-01193-7
 
George, M. M., Platts, S. V., Berry, B. A., Miller, M. F., Carlock, A. M., Horton, T. M., & George, M. H. (2024). Effect of SeaFeed, a canola oil infused with Asparagopsis armata , on methane emissions, animal health, performance, and carcass characteristics of Angus feedlot cattle. Translational Animal Science, 8(August). https://doi.org/10.1093/tas/txae116
 
Greenspoon, L., Krieger, E., Sender, R., Rosenberg, Y., Bar-On, Y. M., Moran, U., Antman, T., Meiri, S., Roll, U., Noor, E., & Milo, R. (2023). The global biomass of wild mammals. Proceedings of the National Academy of Sciences, 120(10), 2017. https://doi.org/10.1073/pnas.2204892120

REPLY AND COUNTER-REPLY TO GREENSPOON:

• Santini, L., Berzaghi, F., & Benítez-López, A. (2024). Total population reports are ill-suited for global biomass estimation of wild animals. Proceedings of the National Academy of Sciences, 121(4), 1–3. https://doi.org/10.1073/pnas.2308958121   
• Greenspoon, L., Rosenberg, Y., Meiri, S., Roll, U., Noor, E., & Milo, R. (2024). Reply to Santini et al.: Total population reports are necessary for global biomass estimation of wild mammals. Proceedings of the National Academy of Sciences of the United States of America, 121(4), 1–2. https://doi.org/10.1073/pnas.2316314121

Jasechko, S., Seybold, H., Perrone, D., Fan, Y., Shamsudduha, M., Taylor, R. G., Fallatah, O., & Kirchner, J. W. (2024). Rapid groundwater decline and some cases of recovery in aquifers globally. Nature, 625(7996), 715–721. https://doi.org/10.1038/s41586-023-06879-8
 
Lang, M. W., Ingebritsen, J. C., & Griffin, R. K. (2024). Status and Trends of Wetlands in the Conterminous United States 2009 to 2019. U.S. Department of the Interior; Fish and Wildlife Service, Washington, D.C. 43 pp. https://www.fws.gov/project/2019-wetlands-status-and-trends-report

Langhammer, P. F., Bull, J. W., Bicknell, J. E., Oakley, J. L., Brown, M. H., Bruford, M. W., Butchart, S. H. M., Carr, J. A., Church, D., Cooney, R., Cutajar, S., Foden, W., Foster, M. N., Gascon, C., Geldmann, J., Genovesi, P., Hoffmann, M., Howard-McCombe, J., Lewis, T., … Brooks, T. M. (2024). The positive impact of conservation action. Science, 384(6694), 453–458. https://doi.org/10.1126/science.adj6598

Li, K., Fisher, J., Power, A., & Iverson, A. (2024). A map of pollinator floral resource habitats in the agricultural landscape of Central New York. One Ecosystem, 9. https://doi.org/10.3897/oneeco.9.e118634
 
Littlefield, C. E., Suraci, J. P., Kintsch, J., Callahan, R., Cramer, P., Cross, M. S., Dickson, B. G., Duncan, L. A., Fisher, J. R., Freeman, P. T., Seidler, R., Wearn, A., Andrews, K. M., Brocki, M., Dodd, N., Gagnon, J., Johnson, A., Krosby, M., Skroch, M., & Sutherland, R. (2024). Evaluating and elevating the role of wildlife road crossings in climate adaptation. Frontiers in Ecology and the Environment, 1–10. https://doi.org/10.1002/fee.2816
 
Pivello, V. R., Vieira, I., Christianini, A. V., Ribeiro, D. B., da Silva Menezes, L., Berlinck, C. N., Melo, F. P. L., Marengo, J. A., Tornquist, C. G., Tomas, W. M., & Overbeck, G. E. (2021). Understanding Brazil’s catastrophic fires: Causes, consequences and policy needed to prevent future tragedies. Perspectives in Ecology and Conservation, 19(3), 233–255. https://doi.org/10.1016/j.pecon.2021.06.005
 
Sutherland, W. J., Bennett, C., Brotherton, P. N. M., Butchart, S. H. M., Butterworth, H. M., Clarke, S. J., Esmail, N., Fleishman, E., Gaston, K. J., Herbert-Read, J. E., Hughes, A. C., James, J., Kaartokallio, H., Le Roux, X., Lickorish, F. A., Newport, S., Palardy, J. E., Pearce-Higgins, J. W., Peck, L. S., … Thornton, A. (2024). A horizon scan of global biological conservation issues for 2024. Trends in Ecology & Evolution, 39(1), 89–100. https://doi.org/10.1016/j.tree.2023.11.001
 
Trencher, G., Nick, S., Carlson, J., & Johnson, M. (2024). Demand for low-quality offsets by major companies undermines climate integrity of the voluntary carbon market. Nature Communications, 15(1), 6863. https://doi.org/10.1038/s41467-024-51151-w
 
UNEP-WCMC, 2024. State of the World’s Migratory Species. UNEP-WCMC, Cambridge, United Kingdom.
https://www.cms.int/en/publication/state-worlds-migratory-species-report
 
Wang, H., Liu, J., Klaar, M., Chen, A., Gudmundsson, L., & Holden, J. (2024). Anthropogenic climate change has influenced global river flow seasonality. Science, 383(6686), 1009–1014. https://doi.org/10.1126/science.adi9501


Sincerely,
 
Jon
 
p.s. I inherited that Christmas sweater from my dad, and typically only pull it out once a year for a Christmas sing-along

December 2024 science summary

Congratulations,

If you're reading this you made it to December! I've got four unrelated reviews this month; the first is a new paper about wildlife road crossings to promote climate adaptation (I'm a minor author).

Also - this is a great piece on how to get better at using AI: https://www.oneusefulthing.org/p/getting-started-with-ai-good-enough The short version is: don't treat AI like a search engine! Give it more context and instructions and let it figure out precisely what you want through iteration. The author says it probably takes ~10 hrs of experimentation to get good enough at using AI for it to be working well.

If you know someone who wants to sign up to receive these summaries, they can do so at http://bit.ly/sciencejon (no need to email me).


WILDLIFE CONNECTIVITY & CLIMATE ADAPTATION:
Littlefield et al. 2024 (I'm a minor author) examines how wildlife road crossings can be beneficial to help species adapt to climate change. We recommend that when siting crossings we should consider a) current wildlife movements, AND expected short-term and long-term shifts in species range and migrations due to b) climate change AND c) human land use change (expansion of housing, ag, etc.). We show how doing this was accomplished for elk in Colorado.
For this to work well, diversion fencing is important to channel wildlife to crossings, and avoiding future fragmentation is key. The paper is open access. There's a press release for the paper here: https://fish.freeshell.org/publications/Littlefield2024-PressRelease.pdf


HORIZON SCANNING / EMERGING ISSUES:
I realized I've only rarely reviewed Bill Sutherland's annual "horizon scan" article listing 15 emerging conservation issues that potentially deserve to be better-known.This year they used artificial intelligence to generate some of the ideas but none made the cut. Here's the final list so you can decide if any are worth looking up:
1. New sources of hydrogen for energy (mining or electrolysis instead of natural gas),
2. Decarbonized ammonia (making fertilizer w/ lower carbon emissions but could increase fertilizer wasted),
3. Feeding people and/or animals w/ cultivated bacteria,
4. Light-free artificial photosynthesis (yes, it's as weird as it sounds) for indoor ag,
5. Enhanced rock weathering at scale (putting rock dust on croplands to sequester carbon),
6. Potential global declines in earthworm populations (more data is needed to see if UK decline is representative),
7. Ecoacoustics to monitor soil ecology (testing how meaningful soil sounds are for estimating things like biodiversity and water flow),
8. Wildfire affecting El Niño and La Niña phase (aerosols leading to the La Niña phase),
9. Benchtop DNA printers (potential to eventually allow guerilla genetic engineering),
10. Better predicting chemical toxicity from early data,
11. a skyscraper city planned in Saudi Arabia that birds could crash into when migrating from Europe to Africa.,
12. Sea urchin die-offs (possibly from disease) leading to algal overgrowth on corals and other marine ecosystems,
13. Ocean-based carbon removal (from the air or dissolved in water to stable forms),
14. Warming "twilight zones" (200-1000m below sea surface) affecting global nutrient and carbon cycles, and
15. Melting Antarctic ice changing deep sea currents.


RIVERS:
Brinkerhoff et al. 2024 (summarized by Harvey & Kampf 2024) asks how much rivers in the continental US originate from ephemeral streams (which rely on rain to flow, as they are always disconnected from groundwater, see Fig 1). The answer is 55% by total streamflow and 59% by total stream length- which may seem surprisingly high at first (and they have a few reasons it's likely an underestimate)! But it makes sense; streams have to start SOMEwhere, and that's either rain or groundwater or a mix. If it's rain those source headwater streams would dry out faster than bigger downstream reaches. Smaller streams and the West are more reliant on ephemeral streams (where they are dry more often), and the Great Lakes region and Florida are the least dependent on ephemeral flow. The paper notes that since they found the majority of river water comes from ephemeral streams, excluding those streams from the Clean Water Act (due to the Sackett ruling) makes it much harder to regulate water quality overall.


FIRE:
Balch et al. 2024 found that over the last 20 years fires in the US have been spreading faster. In the Western US over 20 years the average peak daily growth rate (the average of the fastest each fire grew on a given day) increased 2.5 times (in California they increased by 4 times). The fastest 3% of fires nationally (spreading more than 1,620 ha in a day) destroyed between 78-89% of the buildings lost to fire (the paper lists each number in different section for the same stat). I’ve heard a lot more about severity and frequency and extent of fire, but thinking about speed is also important as faster fires are harder to respond do, and may make really smooth coordination increasingly important. Increases in drought conditions and potential increases in high winds could make this worse over time. 


REFERENCES:
Balch, J. K., Iglesias, V., Mahood, A. L., Cook, M. C., Amaral, C., DeCastro, A., Leyk, S., McIntosh, T. L., Nagy, R. C., St. Denis, L., Tuff, T., Verleye, E., Williams, A. P., & Kolden, C. A. (2024). The fastest-growing and most destructive fires in the US (2001 to 2020). Science, 386(6720), 425–431. https://doi.org/10.1126/science.adk5737

Brinkerhoff, C. B., Gleason, C. J., Kotchen, M. J., Kysar, D. A., & Raymond, P. A. (2024). Ephemeral stream water contributions to United States drainage networks. Science, 384(6703), 1476–1482. https://doi.org/10.1126/science.adg9430

Harvey, J. W., & Kampf, S. K. (2024). The transitory origins of rivers. Science, 384(6703), 1402–1403. https://doi.org/10.1126/science.adq1714

Littlefield, C. E., Suraci, J. P., Kintsch, J., Callahan, R., Cramer, P., Cross, M. S., Dickson, B. G., Duncan, L. A., Fisher, J. R., Freeman, P. T., Seidler, R., Wearn, A., Andrews, K. M., Brocki, M., Dodd, N., Gagnon, J., Johnson, A., Krosby, M., Skroch, M., & Sutherland, R. (2024). Evaluating and elevating the role of wildlife road crossings in climate adaptation. Frontiers in Ecology and the Environment, 1–10. https://doi.org/10.1002/fee.2816

Sutherland, W. J., Bennett, C., Brotherton, P. N. M., Butchart, S. H. M., Butterworth, H. M., Clarke, S. J., Esmail, N., Fleishman, E., Gaston, K. J., Herbert-Read, J. E., Hughes, A. C., James, J., Kaartokallio, H., Le Roux, X., Lickorish, F. A., Newport, S., Palardy, J. E., Pearce-Higgins, J. W., Peck, L. S., … Thornton, A. (2024). A horizon scan of global biological conservation issues for 2024. Trends in Ecology & Evolution, 39(1), 89–100. https://doi.org/10.1016/j.tree.2023.11.001


Sincerely,
 
Jon
 
p.s. The photo is of my neighbor Buddy's old house; the new owners are adding more levels to it but so far have just removed the roof and back and people who walk by are always surprised to see it.

November 2024 science summary

Howdy,

I've got summaries of articles on carbon credits, wetlands and climate mitigation, and the Pantanal (drought, fire, and habitat loss).

But first - two quick notes on the use of artificial intelligence (AI):

1. When I mention AI tools I should say this every time: a) assume that any information you put into an AI may be shared in ways you don't want, so never put in sensitive / non-public information. b) that also means be wary of putting in copyrighted materials! Some publishers like Elsevier and New York Times have a blanket ban on using their publications in AI tools, and others allow some uses but not others!
2. I'm continuing to find Elicit a really helpful tool to find and summarize or extract info from science papers. If you have questions or want to chat about it let me know. If you register for a free account I can send you links to my custom notebooks to show how some cool features work.

If you know someone who wants to sign up to receive these summaries, they can do so at http://bit.ly/sciencejon (no need to email me).

CARBON CREDITS
Trencher et al, 2024 is an analysis of the quality of credits on the voluntary carbon market. They focus on the 20 companies retiring the most credits between 2020-2023 (134 million metric tons CO2e), which is 20% of all global retirements on the three registries (see Fig 1 for company list). They found 87% of credits have a high risk of not providing real additional reductions (6% were low risk, most of the rest was medium), and 97% of credits focused on avoiding emissions rather than removal. Note that they classified all REDD+ (reducing deforestation and/or degradation) as high risk given that they have often 1) overestimated additionality, 2) not stopped deforestation, and/or 3) displaced deforestation elsewhere (aka 'leakage'). They also classify large-scale renewable energy as high-risk, since the price of credits is not typically the decisive factor in those projects (they are often built w/ or w/o credits) and they are often build in countries w strong government support for renewable energy. They also found that companies strongly prefer the cheapest credits (which creates demand for lower-quality offsets) often from older projects, although some companies have paid a lot more for REDD projects. The authors call for more regulation of the voluntary market, and for companies not using voluntary credits to support claims of offsetting emissions.

Blanchard et al. 2024 is a short opinion piece arguing that to fund nature conservation, we should pivot from an "offset" model (where companies buy credits to support assertions of lower net emissions and/or being carbon neutral) to a "contributions" model (where the financial contributions are recognized, but not taken as equivalent to reducing gross emissions). The authors say that 1) all entities should prioritize their own direct emissions reduction before seeking to pay others to do that, 2) we need to use the best science to pick what investments are most likely to lead to durable climate mitigation (considering reversibility, other GHGs, albedo, etc.), and 3) independent scientists should audit any quantitative claims made about the benefits of contributions to climate mitigation.


WETLANDS AND CLIMATE CHANGE MITIGATION
Arias-Ortiz et al. 2024 estimate how much methane different kinds of marshes in the U.S. emit each year. They found that warm freshwater marshes (>25.6C mean annual high temperature) produce the most methane by far (172 g CH4/m2/yr = 48.2 t CO2e / yr), followed by other freshwater marshes at low or medium elevation (producing ~1/3 that on average). Across all marshes the average is much lower (26 g CH4/m2/yr = 7.3 t CO2e / yr), and saltier marshes emit less methane. They report mangroves emit roughly twice as much methane flux as marshes, but seagrasses only emit 10% as much as marshes. Predicted methane was really close to measured methane (at least once they calibrated their estimates)


PANTANAL:
Marengo et al. 2021 is a review of the severe drought in the Pantanal in 2019 and 2020. The key direct cause was less warm humid air coming from Amazonia leading to much less rain across the Paraguay river basin, which in turn led to very low water levels in rivers and other wetlands, which reduced shipping goods by river (and economic losses) and enabled widespread fires. Previous studies looking at Pantanal rainfall trends have found only a small overall decrease but with a lot more variation each year. There are more days with no rain, the dry season has gotten drier, the Ládario river has been dropping ~3 cm / yr for 30 years, but the flooding in 2018 was unusually extensive. Part of the issue may be that the Pantanal has been relatively wet since roughly 1970, making a return to severe droughts that have not been seen for decades feel more unusual (see Fig 3). El Niño does not seem to be a driver of drought, nor do various climatic indices correlate well w/ drought years. But in 2019-2020 a strong South Atlantic Convergence Zone caused a shift in dominant winds to the Pantanal coming from drier and colder higher-latitude air.

Guerra et al. 2020 looked at the drivers of predicted habitat conversion in the Upper Paraguay River Basin (including the Pantanal, some of the Cerrado, and a bit of the Amazon) between 2008-2016 (broken into four 2-year periods). Key drivers in the Pantanal were unprotected status and existing land cover, with much weaker impact from elevation (higher means more loss), and in half the time periods there was also an influence of distance to roads (closer means more loss) and cattle (presence leading to more loss). Oddly there was LESS conversion near annual cropland which is very unusual except in dense fully converted ag landscapes. They only saw more habitat loss on land with good ag potential near rivers in the Pantanal from 2010-2012, which could be related to cropland moving closer to water due to the 2012 drought. Note that this model assumes deforestation expands from where it has already happened, rather than modeling other factors (economic, population modeling, commodity prices, planned roads, etc.) to look for what might change in the future.

Martins et al. 2024 recommend priority areas for fire prevention and/or restoration in the Upper Paraguay River Basin, based on the number of fire-sensitive species present (along w/ factors like fire frequency and intensity, dry biomass, and time since the last burn). The relatively few top priority areas for fire management are in red on Fig 2, and occur in a triangle roughly between Paiaguás, Aquidauana, and Bodoquena. There are many more areas flagged as a priority for restoration, but their top focus is 1,206 km2 of forest high in both resilience and sensitive species. But they also note ~6,000 km2 of potential restoration priorities that hadn't been burnt until recently (2019-2022, Fig 5). The supplement also maps the most important places for fire prevention (Supplementary Fig 15).


REFERENCES:

Arias-Ortiz, A., Wolfe, J., Bridgham, S. D., Knox, S., McNicol, G., Needelman, B. A., Shahan, J., Stuart-Haëntjens, E. J., Windham-Myers, L., Oikawa, P. Y., Baldocchi, D. D., Caplan, J. S., Capooci, M., Czapla, K. M., Derby, R. K., Diefenderfer, H. L., Forbrich, I., Groseclose, G., Keller, J. K., … Holmquist, J. R. (2024). Methane fluxes in tidal marshes of the conterminous United States. Global Change Biology, 30(9). https://doi.org/10.1111/gcb.17462

Blanchard, L., Haya, B. K., Anderson, C., Badgley, G., Cullenward, D., Gao, P., Goulden, M. L., Holm, J. A., Novick, K. A., Trugman, A. T., Wang, J. A., Williams, C. A., Wu, C., Yang, L., & Anderegg, W. R. L. (2024). Funding forests’ climate potential without carbon offsets. One Earth, 7(7), 1147–1150. https://doi.org/10.1016/j.oneear.2024.06.006

Guerra, A., Roque, F. de O., Garcia, L. C., Ochao-Quintero, J. M. O., Oliveira, P. T. S. de, Guariento, R. D., & Rosa, I. M. D. (2020). Drivers and projections of vegetation loss in the Pantanal and surrounding ecosystems. Land Use Policy, 91(April 2020). https://doi.org/10.1016/j.landusepol.2019.104388

Martins, P. I., Belém, L. B. C., Peluso, L. M., Szabo, J. K., Trindade, W. C. F., Pott, A., Junior, G. A. D., Jimenez, D., Marques, R., Peterson, A. T., Libonati, R., & Garcia, L. C. (2024). Fire-sensitive and threatened plants in the Upper Paraguay River Basin, Brazil: Identifying priority areas for Integrated Fire Management and ecological restoration. Ecological Engineering, 209(1), 107411. https://doi.org/10.1016/j.ecoleng.2024.107411

Marengo, J. A., Cunha, A. P., Cuartas, L. A., Deusdará Leal, K. R., Broedel, E., Seluchi, M. E., Michelin, C. M., De Praga Baião, C. F., Chuchón Angulo, E., Almeida, E. K., Kazmierczak, M. L., Mateus, N. P. A., Silva, R. C., & Bender, F. (2021). Extreme Drought in the Brazilian Pantanal in 2019–2020: Characterization, Causes, and Impacts. Frontiers in Water, 3(February). https://doi.org/10.3389/frwa.2021.639204

Trencher, G., Nick, S., Carlson, J., & Johnson, M. (2024). Demand for low-quality offsets by major companies undermines climate integrity of the voluntary carbon market. Nature Communications, 15(1), 6863. https://doi.org/10.1038/s41467-024-51151-w

Sincerely,
 
Jon
 
p.s. these are jack o' lantern vegan quesadillas from our Halloween party

October 2024 science summary

Greetings,

My knee is still healing and as I write this I have COVID. So: I am again behind on proper science reading. BUT I have some fun AI content anyway plus one flashy new paper.

AI TO GENERATE PODCASTS?!
Many of you requested updates on important AI features and this month is a biggie. Google's Gemini Notebook (https://notebooklm.google/) which among other more established features turns a body of text into an NPR-style podcast (a blog about the feature is here: https://blog.google/technology/ai/notebooklm-audio-overviews/). 
 
I would share a direct link to the audio it produces to avoid the energy use of you all trying it on your own, but my employer's AI guidance doesn't let me do that, so I'll just say: watch a little less streaming video this week to reduce your carbon footprint, and give this a go. Just 1) upload a document to https://notebooklm.google, and 2) click Generate in "Deep dive conversation". Wow. The results are conversational, natural, and interesting, with relatively few hiccups / artifacts that I noticed (although not none), although it does consistently hype up each paper (both the magnitude and significance of results are exaggerated, albeit not quantitatively). I could see this being useful to help you digest that report you can't bring yourself to read while jogging instead. Not that you should ever trust an AI summary at this point to be accurate (please don't!) - but for legit reports it appears to be much better than not reading the report at all from my limited testing.

Here are the results of four quick tests: 

1. A colleague fed in a research report which was written for a lay audience already (https://www.pewresearch.org/data-labs/2024/05/23/electric-vehicle-charging-infrastructure-in-the-u-s/), and I was gobsmacked by the quality. Not as good as a legit pro quality podcast, but MUCH better than something I would put out and a hell of a good first draft.
2. What about a peer-reviewed science article which is much more technical and hard to read? I uploaded my 2nd favorite paper that I'm first author on (since my favorite is written in plain English already) which is about how spatial resolution impacts accuracy, cost and making the right decision: http://onlinelibrary.wiley.com/doi/10.1002/rse2.61/full Once again it did really surprisingly well. There was one weird audio screwup, and they focused a moderate amount on an unimportant finding but also had a line I loved: “sharper images leading to sharper insights” (meaning higher spatial resolution of satellite imagery is more accurate and makes for better decisions). Damn that's good!
3. OK, but what about a paper even a proper scientist would have a hard time slogging through? I literally searched all the notes I have written in my reference library notes for the phrase "hard to read" and found this doozy looking at how cow genetics affects methane emissions: https://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1005846 The writing is very technical BUT at least for a reader like me you can skim and sift out some high level conclusions so I was curious to see how it would perform. The answer is still quite well with one big caveat! The use of sire progeny groups was charmingly described as "like a bovine family reunion, but for science" and they had some great metaphors like how a microbe has a "key" to unlock the "lock" of some important sugar molecules. BUT they described the results as finding a MASSIVE and INSANE impact of genetics on methane and how it was a TOTAL GAME CHANGER. In fact, while the authors never clearly state this (though it's obvious in Fig 1), genetic impacts are MUCH smaller than the impact of diet (grass / forage vs. concentrated feed). So like a cow's stomach, this tool will regurgitate back what you put in w/o any filtering or warning.
4. What if you upload a blatantly false document? You guessed it - the tool performs the same way and makes it seem engaging and interesting. A colleague uploaded an Onion article and the tool did NOT waver or flag any parody or provide any warning, it just made it sound like real news. This one is pretty scary.

Note that there were literally no other prompts or edits to produce this, just upload a PDF and click "generate" which I find staggering. I would have believed that these were real podcasts w/ real people, and it definitely took the core content and made it interesting and engaging (albeit over-hyped). Hearing three of these in a row, there is some noticeable repetition in key phrases and style which will make my spidey-sense tingle if I hear similar podcasts out in the wild not attributed to Gemini Notebook.

As the always wise Bob Lalasz from Science+Story noted - this tool cannot (yet) simulate specific voices like a researcher or celebrity, and the output will quickly saturate and land as inauthentic. But at this moment it's both a tool that can provide some useful and engaging summaries, AND could be a way to make misinformation seem more appealing, as the Onion example shows.

Enough AI, here's a review of one actual paper I read w/o AI helping:

CATTLE AND CLIMATE CHANGE:
OK, for years people have been hyping the potential of a kind of seaweed (Asparagopsis) to reduce methane emissions in cattle. But the in vitro evidence was mixed - with potential toxicity and downsides a concern if the dose wasn't just right. George et al is a live trial with good news! They found methane emissions from cattle given an Asparagopsis additive were cut roughly in half compared to control, with 6.6% higher weight gain per unit of feed and no substantial impacts on quality or health (fat color maybe a bit better, tenderness maybe a bit worse). The methane reduction peaked at day 21 and declined afterwards, but since most cattle are in feedlots only ~3 months (ranging from 1.5-4) the decline after day 100 is pretty moot. That's a lot of potential! The only potential downsides were ~50% higher bromine residues in kidney and muscle (I couldn't quickly find guidance on safe levels). Caveats: 1) there were no conflicts declared but the authors appear to almost all work as feedlot consultants and it's single rather than double-blinded, 2) in the US the feedlot phase is only about 15% of the lifecycle emissions of a cow (and of that, some is from growing crops and nitrous oxide) so TOTAL impact on CO2e / kg beef is not as dramatic. Overall my take is 1) this should absolutely be tested and replicated more - anything that reduces the very high carbon of beef is worth pursuing. BUT 2) if this is marketed as "green beef" or license to avoid reductions, it could be net harmful for the climate. and 3) IF spraying this solution on grass worked similarly and didn't inhibit development of calves, the impact could be much higher (since ~80%ish of a cow's life is grazing prior to feedlot, and methane emissions are higher on grass than feed). So let's test that too. There's a blog about this at https://www.theguardian.com/australia-news/article/2024/aug/18/feeding-seaweed-supplement-to-cattle-halved-methane-emissions-in-australian-feedlot-study-finds

As always, if you know someone who wants to sign up to receive these summaries, they can do so at http://bit.ly/sciencejon (no need to email me).


REFERENCES:
Fisher, J. R. B., Acosta, E. A., Dennedy-Frank, P. J., Kroeger, T., & Boucher, T. M. (2018). Impact of satellite imagery spatial resolution on land use classification accuracy and modeled water quality. Remote Sensing in Ecology and Conservation, 4(2), 137–149. https://doi.org/10.1002/rse2.61

George, M. M., Platts, S. V., Berry, B. A., Miller, M. F., Carlock, A. M., Horton, T. M., & George, M. H. (2024). Effect of SeaFeed, a canola oil infused with Asparagopsis armata , on methane emissions, animal health, performance, and carcass characteristics of Angus feedlot cattle. Translational Animal Science, 8(August). https://doi.org/10.1093/tas/txae116

Roehe, R., Dewhurst, R. J., Duthie, C.-A., Rooke, J. A., McKain, N., Ross, D. W., Hyslop, J. J., Waterhouse, A., Freeman, T. C., Watson, M., & Wallace, R. J. (2016). Bovine Host Genetic Variation Influences Rumen Microbial Methane Production with Best Selection Criterion for Low Methane Emitting and Efficiently Feed Converting Hosts Based on Metagenomic Gene Abundance. PLOS Genetics, 12(2), e1005846. https://doi.org/10.1371/journal.pgen.1005846

Sincerely,
 
Jon
 
p.s. This hairless cat named Sylvester lives near me, is extremely friendly, and is as weird to touch as you might guess

September 2024 science summary (nut sustainability & freshwater protection in Chile)

Hi,

I didn't read much science this last month. I had knee surgery instead (the pic above shows the cool leg squeezing machines and icing machine I got). But I've got a review of one article on freshwater protection in Chile, AND as a treat a guest review from Randy Swaty and Sarah Bixby of an article comparing the pros and cons of different kinds of nuts! They even included some discussion questions. If you are reading this and want to do a guest review just let me know!

If you know someone who wants to sign up to receive these summaries, they can do so at http://bit.ly/sciencejon (no need to email me).

NUTS! (review by Randy Swaty and Sarah Bixby):

Walnuts for the win? Well, it depends.  Being a conscientious consumer is challenging.  Just try to figure out which nuts are most sustainable.  A Google search turned up typical top-10 lists and shallow articles.  Google scholar pointed us to Cap et al., 2023 which assesses 8 nuts and 2 seeds (see article for specifics) against 3 environmental, 2 nutritional and 6 social criteria.   We did not come away with a clear answer, but learned: 1) indicators we thought of (e.g., transportation and packaging) were not included (see citation they reference Tillman and Clark, 2014), 2) walnuts and sunflower seeds generally ranked the highest with cashews ranking the lowest (by far), 3) Figure 5 was a favorite, where the authors rank nuts based on ‘regret’.  Surprisingly, while just two of the eleven criteria are nutrition criteria, chestnuts’ poor nutrition ranking knocked the tree nut right out of the least regret category and 4) seeds outperformed nuts on nutritional criteria-we’ll be looking for more data on seeds.  The authors also present some hope (mostly-as usual there’s exceptions) in Figure 6 where they report “improvement” in 10 of their 11 criteria if consumption patterns followed the baseline rank order.

Jon's side note: In the first draft of this review they also had discussion questions; we cut them for brevity but I loved the idea and the curiosity this article spawned for them! Email me if you want to be connected w/ Randy and Sarah to follow up :) 

FRESHWATER PROTECTION:
Weber Salazar et al. 2024 is a legal analysis overview of freshwater protection in Chile. While Chile lacks a national river conservation system, there are several relevant policies including: the water code which recognizes water as a public good and establised theoretically required minimum ecological flows (via updates in 2005 and 2022), regulations of protected areas and forests, urban wetlands law (for estuaries near urban developments), and recreational fishing law. Water quality standards are weak (limiting both which pollutants are covered and where they apply). The 2022 new constitution offered a new water framework, but it was rejected (as was another consitution in 2023 with much weaker environmental protection). Granting water rights for environmental purposes has been quite limited but there are efforts to improve that. The authors also surveyed 1,612 Chileans (plus 30 semi-structured interviews) about attitudes towards river and river protection. 85% said they had a connection to a specific river (80% a river near where they lived. with tourism the most frequently mentioned connection followed by cultural and a source of water), and 99% of respondents said protection of Chilean rivers was necessary (44% favored legislation for specific rivers, 33% preferred constitutional protection, and 22% favored protected areas). There's a lot more interesting results here (more than I can fit in a short summary) and I recommend a closer look to anyone working in Chile.



REFERENCES:

Cap, S., Bots, P. and Scherer, L., 2023. Environmental, nutritional and social assessment of nuts. Sustainability Science, 18(2), pp.933-949. https://link.springer.com/article/10.1007/s11625-022-01146-7

Weber Salazar, P., Macpherson, E., & Willaarts, B. A. (2024). Towards durable legal protections for rivers in Chile. Water International, 00(00), 1–24. https://doi.org/10.1080/02508060.2024.2346394

Sincerely,
 
Jon

August Science Summary (fire in the Pantanal)

Hi,

This month I'm focusing on a single issue (fire in the Pantanal) but also advertising a new preprint I'm an author on. Fires in the Pantanal this June broke the record for that month (we have records of about 20 years) so it seemed timely!

If you know someone who wants to sign up to receive these summaries, they can do so at http://bit.ly/sciencejon (no need to email me). Unsubscribe via the link at the end.

RAPID EVIDENCE ASSESSMENTS (REA):
I'm an author on a new preprint (not yet peer-reviewed) about rapidly assessing evidence in conservation (Schofield et al. 202X). It's the conclusions of a working group hosted by EPA which met over several online workshops to try and build consensus for a definition and approach since there are many competing ones out there. "Rapid" in this case is relative to systematic reviews - it doesn't mean doing the kind of informal scan of science literature that is pretty common at NGOs. We argue that it's important to balance speed w/ rigor to avoid either wasting effort on unnecessary detail or arriving at the wrong answer by rushing. The definition kind of hits the high points of the topics the paper covers: "REA is a structured review process that aims to maximize rigor and objectivity given assessment needs and resource constraints (e.g., time). REA aims to address requirements for timely and cost-efficient decision-making while maintaining confidence in conclusions. REA is typically more rigorous than less formalized practices such as traditional narrative literature reviews, but effort is reduced relative to comprehensive evidence assessment approaches such as systematic review. REA is transparent, well-documented, and the details of the specific methods used at each step are justified. Those who commission, conduct, and use REAs should be cognizant of the achievable levels of confidence in the conclusions that accompany the rapid application of different steps in the REA process." Let me know if you have questions, criticisms, ideas, etc. https://osf.io/u7z2g


FIRE IN THE PANTANAL:
Damasceno-Junior et al. 2023 covers flood and fire dynamics in the Pantanal and the need for integrated fire management (IFM), using the 2020 wildfires as a case study. The Pantanal burns the most in the dry season (Aug-Oct, Fig 5). From 2003-2019, ~5-15% of the biome burned each year (Fig 7); roughly half never burned and of the areas that did almost all burned no more than 4 times over 16 years (Fig 6In 2020 about 30% burned! It was a very dry year (the bottom ~5% over the last 120 years, and the worst in 47 years), but not the dryest on record (Fig 3). The drought allowed the fire to spread via soil as well as above ground. The authors believe that despite being the most severe fire on record, similar fires likely happened in past droughts. Note that cattle can both drive wildfire (by setting fires to clear vegetation) and reduce it (by reducing biomass available to burn). Key recommendations include: 1) better integration of information and decision makers (including between Mato Grosso and Mato Grosso do Sul; they worked together but not enough), 2) mobilization of additional people (federal natural resource staff, local police and firefighters, private fire brigades, NGOs, volunteers, etc.), 3) inclusion of Pantanal residents w/ traditional knowledge, 4) more research on the interaction of fire and floods in the Pantanal, 5) better fire forecasting and better communication about those risks (including to land managers who set fires).

Garcia et al. 2021 is an overview of fire in the Pantanal, and a call for an integrated fire management (IFM) program in the Pantanal. Water moves slowly through the Pantanal; it takes 3 months for rainfall in the watershed to reach the southern Pantanal via the Paraguay river. This means that near Corumbá typically there is flooding during the dry season (preventing fires in the floodplain), and water levels are lowest in December (after the rainy season has begun). But the 2020 wet season had 60% less rain than normal. That meant dead vegetation from 2019's flood combined w/ a lack of flooding provides fuel for wildfires. 43% of the area that burned in 2020 hadn't burned before since records began in 2003 (areas in gray in Fig 1). They noted that fire management in 2020 was hampered by COVID-19 (fewer firefighters were available, and had to socially distance from each other). Climate change is expected to bring more drought years, exacerbated by deforestation in the neighboring Amazon and Cerrado. The authors call for removing invasive African grasses (like Urochloa / Brachiaria) and note a 2021 IFM plan actually incentivizes planting cultivated grass. They also recommend more prescribed burns in the wet season, safe fire training for ranch workers, more funding for fire prevention, better warning systems, and increasing the participation of Indigenous people in fire brigades.

Pivello et al. 2021 is a good comprehensive overview of wildfire across Brazil. It's long and dense so hard to summarize! Natural fires are most common at the beginning of the wet season when lightning ignites accumulated dry vegetation. Fig 1 has an overview of fire by biome: the Amazon followed by Cerrado have the most fires; the Pantanal and Cerrado typically have the highest % burned (they are both fire-dependent, as is the Pampas, see Fig 2), and in 2020 the Pantanal had roughly triple the % burned and fire density as others. Pollen evidence (from a different study, Power et al. 2016) indicates fire activity in the Pantanal peaked about 12,000 years ago (people have only lived there for about 8,000 years, and grazed cattle for ~250). Introducing cattle has caused a shift from burning every 3-6 years (mostly in the beginning or sometimes end of the wet season) to burning every year or two during a relatively dry part of the wet season (see Fig 6). Conversely, fire suppresion in the Cerrado has also driven woody encroachment of savannas. In the Amazon and Atlantic Forest, natural fire is rare and very infrequent, making fire especially harmful as species are not adapted to it. The combination of deforestation and drought make it much easier for fire to spread (and Amazonian deforestation means more drought in the Pantanal). 1/3 of the forest in the Amazon from 2003-2019 were associated w/ deforestation. Indigenous people mostly used fires in small areas, but since European colonization it's used at larger scales to clear land permanently (or alternately supressed, see Fig 7 for a nice timeline of fire landmarks). Integrated fire management (IFM) is uncommon (except a few federal protected areas, mostly in the Cerrado). Only Minas Gerais and Roraima states have IFM laws. The authors recommend: 1) fire management policy should include climate mitigation and poverty reduction to reduce fire risk; 2) better fire monitoring and management systems; 3) filling knowledge gaps around drivers of fire, how fire impacts wetlands, human dimensions of fire, impacts of different fire regimes on grazing productivity and carbon; 4) better enforcement of illegal fire use (including more resources); 5) including local communities in developing fire management plans, and 6) national and state level fire policies with adequate resources for implementation (including data collection and sharing, and clear and simple rules about fire use).

Oliveira et al. 2021 looks at the impact of Indigenous fire brigades in the Kadiwéu Indigenous territory (where the Cerrado meets the Pantanal). They compared 2001-2008 (no Indigenous fire brigades) to years when they were active (2009-2018; the first 5 years they tried to suppress all fires and the last 5 they used integrated fire management). While a before/after study isn't a true control, the years w/ the fire brigades had 53% less area burned, the area that burned often (70% of the years in each period) declined by 84%, and areas with no fire increased by 86% (note the % reported in the text doesn't match the number of acres, I'm using the latter). Interestingly the number of days without rain affected the area burned w/o the brigades, but when the brigades were active climatic factors had much less influence. The authors note that the reduced fire frequency allowed forests to expand and grasslands to shrink; it wasn't clear which was their more natural historic state.

Arrua et al. 2023 asked how fire frequency and severity affected sun spiders in the Kadiwéu Indigenous Reserve. They considered fire every 1-2 years frequent, w/ every 3-4 years infrequent. Spider abundance was not significantly affected by fire frequency or timing, but the most spiders were seen 1 month after a fire (perhaps b/c of bugs that like young leaves eating the new shoots).

dos Santos Ferreira et al. 2023 found that patchy and variable fire regimes (but avoiding high fire frequency from July to December) leads to flowers and fruits being continuously available in the Kadiwéu Indigenous territory . They recommend a seasonal patch-burning mosaic without trying explicit to optimize flower and fruit production.


REFERENCES:
Arrua, B. A., Carvalho, L. S., Teles, T. S., Oliveira, M. da R., & Ribeiro, D. B. (2023). Fire Has a Positive Effect on the Abundance of Sun Spiders (Arachnida: Solifugae) in the Cerrado-Pantanal Ecotone. Fire, 6(2), 1–12. https://doi.org/10.3390/fire6020069

Damasceno-Junior, G. A., Roque, F. de O., Garcia, L. C., Ribeiro, D. B., Tomas, W. M., Scremin-Dias, E., Dias, F. A., Libonati, R., Rodrigues, J. A., Lemos, F., Santos, M., Pereira, A. de M. M., de Souza, E. B., Reis, L. K., da Rosa Oliveira, M., Souza, A. H. de A., Manrique-Pineda, D. A., Ferreira, B. H. dos S., Bortolotto, I. M., & Pott, A. (2021). Wetland Science. In B. A. K. Prusty, R. Chandra, & P. A. Azeez (Eds.), Wetland Science & Practice (Vol. 38, Issue 2). Springer India. https://doi.org/10.1007/978-81-322-3715-0

dos Santos Ferreira, B. H., da Rosa Oliveira, M., Mariano Fernandes, R. A., Fujizawa Nacagava, V. A., Arguelho, B. A., Ribeiro, D. B., Pott, A., Damasceno Junior, G. A., & Garcia, L. C. (2023). Flowering and fruiting show phenological complementarity in both trees and non-trees in mosaic-burnt floodable savanna. Journal of Environmental Management, 337(February), 117665. https://doi.org/10.1016/j.jenvman.2023.117665

Garcia, L. C., Szabo, J. K., de Oliveira Roque, F., de Matos Martins Pereira, A., Nunes da Cunha, C., Damasceno-Júnior, G. A., Morato, R. G., Tomas, W. M., Libonati, R., & Ribeiro, D. B. (2021). Record-breaking wildfires in the world’s largest continuous tropical wetland: Integrative fire management is urgently needed for both biodiversity and humans. Journal of Environmental Management, 293(April), 112870. https://doi.org/10.1016/j.jenvman.2021.112870

Oliveira, M. R., Ferreira, B. H. S., Souza, E. B., Lopes, A. A., Bolzan, F. P., Roque, F. O., Pott, A., Pereira, A. M. M., Garcia, L. C., Damasceno, G. A., Costa, A., Rocha, M., Xavier, S., Ferraz, R. A., & Ribeiro, D. B. (2022). Indigenous brigades change the spatial patterns of wildfires, and the influence of climate on fire regimes. Journal of Applied Ecology, 59(5), 1279–1290. https://doi.org/10.1111/1365-2664.14139

Pivello, V. R., Vieira, I., Christianini, A. V., Ribeiro, D. B., da Silva Menezes, L., Berlinck, C. N., Melo, F. P. L., Marengo, J. A., Tornquist, C. G., Tomas, W. M., & Overbeck, G. E. (2021). Understanding Brazil’s catastrophic fires: Causes, consequences and policy needed to prevent future tragedies. Perspectives in Ecology and Conservation, 19(3), 233–255. https://doi.org/10.1016/j.pecon.2021.06.005

Power, M. J., Whitney, B. S., Mayle, F. E., Neves, D. M., de Boer, E. J., & Maclean, K. S. (2016). Fire, climate and vegetation linkages in the bolivian chiquitano seasonally dry tropical forest. Philosophical Transactions of the Royal Society B: Biological Sciences, 371(1696). https://doi.org/10.1098/rstb.2015.0165


Sincerely,
 
Jon
 
p.s. The picture above is a sunset at Cape May National Wildlife Refuge

July 2024 science summary

Hello,

I've just got two science articles this month, but also wanted a plug a book I found really interesting: The Culture Code by Daniel Coyle. There's not a lot of brand new content - he draws heavily on concepts of psychological safety and vulnerability (see Amy Edmondson), learning from failure, how to give effective feedback, ways to generate candor and tough love, making space for feedback, etc.

The reason this one stuck w/ me is that he has pretty compelling real world examples of organizations and leaders that embody some of the recommendations. One of his suggestions was also new to me and really resonates: "resist the temptation to reflexively add value." I've thought before about 1) whether or not my review or input can make something better and how much, and 2) whether I'd add enough value for it to be worth my time. But he notes that 3) every time you weigh in on something, you're missing a chance to express trust in the author and build their confidence that they don't NEED your input for it to be good enough. I'm still grappling with how to put this into practice, but the book is a fast read and I recommend it.

If you know someone who wants to sign up to receive these summaries, they can do so at http://bit.ly/sciencejon (no need to email me).


MAMMALS:
Greenspoon et. al 2023 is an attempt to estimate the biomass of all wild mammals on earth (combined), arriving at 60 Mt total: 20 Mt (million metric tons) on land (half from "even-hoofed" mammals, see FIg 2), and 40 Mt in oceans (23 Mt of which comes from baleen whales). But the kicker is that they estimate human biomass at 390 Mt, and livestock biomass at 630 Mt (420 Mt from cattle: which is more than all humans plus all wild land mammals). Fig 4 awkwardly tries to compare all mammal biomass on earth, showing how wild species have been squeezed. The wild mammal estimates mostly come from the IUCN red list which skews towards expert assessments of more threatened spp., and the numbers won't be "right" for several reasons (these estimates are hard, and the data are highly limiting). But it seems solid that humans and livestock substantially outweigh wild mammals.
There's a good critique of the paper (arguing that Greenspoon et al. underestimate biomass by a factor of 5.5) by Santini et al. here https://www.pnas.org/doi/10.1073/pnas.2308958121 and a reply from the Greenspoon authors pointing out why the methods used in the critique are also (differently) flawed: https://www.pnas.org/doi/10.1073/pnas.2316314121


PANTANAL / CATTLE RANCHING:
Junk and da Cunha 2012 argue that when ranchers clear trees and shrubs from grazing lands, that should not be equated with deforestation. They note that from the perspective of ranchers, all trees and shrubs within pastures (whether native or not) are "invasive species." It's unusual to use that language to describe the regeneration of trees in what used to be forest (as of ~250 years ago before cattle were introduced) but makes sense from the perspective of someone trying to keep land suitable for cattle (and they note the land was managed for thousands of years to promote other wild game species, making parts of the Pantanal a cultural landscape). Table 1 lists their recommended methods to clear some of the more common woody species. They also discuss how starting in the 1980s, money from a gold rush was used to drive higher-density cattle ranching using African grass species.


REFERENCES:
Greenspoon, L., Krieger, E., Sender, R., Rosenberg, Y., Bar-On, Y. M., Moran, U., Antman, T., Meiri, S., Roll, U., Noor, E., & Milo, R. (2023). The global biomass of wild mammals. Proceedings of the National Academy of Sciences, 120(10), 2017. https://doi.org/10.1073/pnas.2204892120

REPLY AND COUNTER-REPLY TO GREENSPOON:

• Santini, L., Berzaghi, F., & Benítez-López, A. (2024). Total population reports are ill-suited for global biomass estimation of wild animals. Proceedings of the National Academy of Sciences, 121(4), 1–3. https://doi.org/10.1073/pnas.2308958121   
• Greenspoon, L., Rosenberg, Y., Meiri, S., Roll, U., Noor, E., & Milo, R. (2024). Reply to Santini et al.: Total population reports are necessary for global biomass estimation of wild mammals. Proceedings of the National Academy of Sciences of the United States of America, 121(4), 1–2. https://doi.org/10.1073/pnas.2316314121

    
Junk, W. J., & Nunes da Cunha, C. (2012). Pasture clearing from invasive woody plants in the Pantanal: a tool for sustainable management or environmental destruction? Wetlands Ecology and Management, 20(2), 111–122. https://doi.org/10.1007/s11273-011-9246-y



Sincerely,
 
Jon
 
p.s. This is a baby rabbit nibbling a weed in my garden. We had a nest of even tinier ones born more recently, but this guy was the cutest of them all.