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I'm an author on a new preprint (not yet peer-reviewed) about rapidly assessing evidence in conservation (Schofield et al. 202X).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
