January 2020 science journal article summary: best of 2019

Happy new year!

I’ve decided once again to kick the new year off by listing my favorite 15 articles that I reviewed last year. I picked them for a mix of importance and being interesting, plus my favorite two publications that I contributed to (Bradford et al. 2019, Fisher & Kareiva 2019). If you know someone who wants to sign up to receive these summaries, they can do so at http://bit.ly/sciencejon

I also have gotten a great response from a webinar I hosted in December on how scientists can improve the impact of their research! If you weren't one of the almost 1,000 registrants, you can watch the webinar here: https://www.openchannels.org/webinars/2019/improving-your-impact-guidelines-doing-science-influences-policy-and-management It's about 23 minutes of presentation followed by lots of Q&A and discussion, and you can also download the full paper the talk is based on from http://bit.ly/strongerscience 

Anderson et al. 2019 argues that while investing in natural climate solutions (aka NCS, e.g. trees) is important to mitigate climate change, cuts to emissions from energy and industry are also urgent and imperative. As they put it, it's not "either/or" but "yes, and." Their key point is that while NCS offer many benefits, delaying emissions reductions from energy and industry by even a few years can add up to more than offset the reductions from NCS. They close by calling for conservationists to ensure that NCS mitigation is optimized, while also amplifying the need to work on complementary solutions to reduce anthropogenic emissions at their source.

Bradford et al. 2019 is an opinion piece on soil carbon. The opening two lines sum it up well: "Soil-based initiatives to mitigate climate change and restore soil fertility both rely on rebuilding soil organic carbon. Controversy about the role soils might play in climate change mitigation is, consequently, undermining actions to restore soils for improved agricultural and environmental outcomes." In other words, while scientists disagree a lot about whether boosting soil carbon is useful for climate mitigation, we all pretty much agree it's important for fertile and productive agricultural lands. Read a bit more at http://sciencejon.blogspot.com/2019/11/soil-carbon-what-is-it-good-for.html  or just read the paper (it's only 1,800 words).

Burivalova et al. 2019 is a literature review of how effective four strategies were in delivering environmental, social, and economic outcomes. They looked at creating protected areas (PAs), forest certification and reduced impact logging (RIL), payment for ecosystem services, and community forest management. The results are varied and complex but Figure 2 summarizes them very well - no strategies always succeed, but all sometimes succeed (and note the caveat that each square is not equivalent). PAs performed well environmentally (after certification & RIL), but very poorly socially and economically. The authors conclude that there are surprising gaps in the literature on monitoring the efficacy of conservation strategies, and that before implementation local evidence should be examined to minimize the chance of failure or even having a strategy backfire.

Catalano et al. 2018 argues that conservation would do well to learn how to deal with failure from other disciplines like medicine, business, and aviation. Specifically, we need to recognize how much we can learn from failure (sometimes more than success), rather than fearing it and avoiding tough measures as a result. They cover how we learn from failure, why it's hard to constructively engage with it, how understanding cognitive biases can help (see Table 1 for a great list to consider), and the role of leaders in supporting efforts to identify and learn from failure. The example of "no rank" military aviation debriefs is interesting - they promote a culture with sharing useful feedack at its core. My main take-away is that dealing with failure is not only key, but it's hard and requires careful thought to do well.

The U.N.'s Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) released a summary of a major report in May describing global biodiversity loss and extinctions (Diaz et al. 2019). The short version is "nature is in trouble, and so are we as a result." The most reported estimate is that about 1 million species face extinction (many within decades) unless we act to prevent that. I'd recommend looking at the policy summary and at least reading the bold headlines to get a bit more of the key findings. A few others worth highlighting include: declines in crop and livestock diversity is undermining agricultural resilience, drivers of change in nature (e.g. land use, direct exploitation, climate change, pollution, and invasives) are accelerating, goals like the Aichi Biodiversity Target and the 2030 Agenda for Sustainable Development cannot be met without major transformative changes (changes which are possible, albeit challenging), the parts of the world where declining nature is expected to hit people the hardest tend to be poor and/or indigenous communities, international cooperation to build a more sustainable global economy will be key to solve this problem, addressing the sustainability of food will also be important, and land-based climate solutions (e.g. bioenergy plantations and afforestation) have some tradeoffs. Many of these are obvious; the summaries under each headline often include useful detail, but there's too much to summarize at this level. So skim through and dive into the topics that pique your interest. Download the whole report from https://ipbes.net/global-assessment

My long-overdue book chapter "Using environmental metrics to promote sustainability and resilience in agriculture" (Fisher & Kareiva 2019) came out in "Agricultural Resilience: Perspectives from Ecology and Economics" from Cambridge University Press: https://www.cambridge.org/gb/academic/subjects/life-sciences/ecology-and-conservation/agricultural-resilience-perspectives-ecology-and-economics?format=PB Unfortunately I wrote it when I knew far less about agriculture, but it has some useful content. The section "Food labels and sustainability" is still unique as far as I know in providing a concise (2 page) summary of research around food labels and consumer preferences around sustainability (although there are more comprehensive resources, e.g. "The Green Bundle" by Magali Delmas and David Colgan). The corporate sustainability information is badly dated but a decent primer for folks new to the field. Anyway, you can read my chapter here if interested: http://fish.freeshell.org/publications/FisherKareiva_CUP_2019_preformatted.pdf or buy the book from the link above.

Grill et al. 2019 estimates only about a third of the world's longest rivers (<1,000 km) are freely flowing (defined here with a new metric that means neither dammed, nor significantly impacted by water consumption or infrastructure in riparian areas and floodplains). Those long free rivers are mostly in remote parts of the Amazon, Arctic, and Congo. On the other hand, shorter river reaches are doing better: 56% of long rivers (500-1000km) are freely flowing, rising to 80% and 97% for medium (100-500km) and short (10-100km) rivers respectively. However, since they rely on global dam databases, they caution that they likely overestimate freely flowing rivers due to missing data on small dams. The figures (and table 1) have great details on how well connected each river reach is, what limits connectivity most (96% one of the impacts of dams: fragmentation, flow regulation, and sediment trapping), and connectivity broken down by river length.

Kennedy et al. 2019 calculates how modified by human activities land around the world is. While only 5% of land area was 'unmodified', most of the world was 'moderately modified.' The authors argue that ecoregions with moderate modification may be good candidates for high priority conservation action, because they tend to have some relatively intact lands near to highly modified lands (which thus may pose a threat in the near future). In particular, the tropical and subtropical dry broadleaf forests biome (mostly in Mexico, India, Argentina, & SE Asia) was found to be the most threatened (high conversion relative to protection). While they didn't include all threats (e.g. logging, invasive species, climate change, and more) these data can be used to evaluate the suitability of lands for protection. You can explore the findings and maps at http://gdra-tnc.org/current/ and you can download the data from http://s3.amazonaws.com/DevByDesign-Web/Apps/gHM/index.html

Li et al. 2015 compares the net impact of different kinds of forests on local weather, considering albedo and evapotranspiration. Their key finding is that "tropical forests have a strong cooling effect throughout the year; temperate forests show moderate cooling in summer and moderate warming in winter with net cooling annually; and boreal forests have strong warming in winter and moderate cooling in summer with net warming annually." This means that the net climatic effect (accounting for carbon sequestration as well as local weather) of tropical forests (and to a lesser extent, temperate forests) is stronger than indicated by carbon alone, while for boreal forests the carbon benefit is significantly offset.

Minx et al. 2018 is an overview from a 3-part series on negative emissions (which they define as reforestation, soil carbon, biochar, BECCS, DACCS, enhanced weathering & ocean alkalinization, and ocean fertilization). Table 2 summarizes potential impact and costs from various studies, and Fig 6 has a great visual synthesis of these data. They find afforestation, reforestation, and soil carbon as ready for large-scale deployment (albeit reversible), and all but ocean fertilization as having potential to deliver benefits by 2050. There are lots of other good insights here and it's worth reading.

Two new lidar satellites were launched recently: ICESat-2 launched in Sep 2018 and GEDI in Dec (initial GEDI data should be released in June, ICESat-2 hasn't announced a date yet). While GEDI is more focused on measuring forest canopy height, ICESat-2 is also mapping vegetation (in addition to ice sheets, clouds, land surface, and more). GEDI will focus on middle latitudes, and ICESat-2 on the poles. Having these data available globally will be a big deal, especially for estimating forest carbon. For more on ICESat-2, Neuenschwander and Pitts 2019 has details on one of the planned data products (ATL08) which maps both ground surface and tree canopies. It's a dense paper, but Figures 4 & 8 are useful to get a sense of the output (they used simulated data), and the discussion has several useful details. The raw data is grouped into 100m cells to have enough photons per cell, but another data product (ATL03) maps each photon individually and can be used to investigate patterns within each 100m cell. Note that tree canopy height is consistently underestimated by ATL08.

Soil organic carbon (SOC) is often claimed to improve crop yields.  Oldfield et al. 2019 tests that claim with a global meta-analysis of maize and wheat. They find higher SOC is associated with higher yields, up to ~2% SOC. They then look at the ~2/3 of global maize and wheat lands below 2% to estimate the opportunity to improve yield by boosting those soils to 2% SOC. Globally they estimate that we could produce ~5% more maize and ~10% more wheat, which represents 32% of the global yield gap for maize (largely in the US), and 60% for wheat (largely in China). Check out Figure 4 for global opportunity maps. Note that there is a lot of variance in the data, and it's even possible yields could decline slightly as SOC increases.

Pohl et al. 2017 is a cool but unusual science paper. The authors provide clear instructions in 10 steps for researchers to improve their impact (similar to the concepts in Enquist et al. 2017 but aimed at implementation). Table 1 has a great summary of the process - at a high level they recommend matching research questions to knowledge needed to inform action, thinking about who to involve (e.g. stakeholders) throughout the research process, and reflecting on lessons learned. The authors have walked a variety of researchers through these 10 steps in a single day. Steps 5-9 provide helpful tips on how to identify a body of stakeholders, and figure out how to break them down into who to co-produce knowledge with, who to consult with, and who to simply inform. It seems like a great framework to get scientists started, although it's a bit ironic to have scientists think on their own about how to better incorporate input and perspectives from stakeholders.

Sanchez-Bayo & Wyckhuys 2019 looks across 73 studies of insect decline from cross the world, and look at the drivers and other commonalities. A key limit of the paper is that they excluded any study that did NOT show a chance in abundance or diversity, so its utility is limited to explaining declines where they have happened (see section 4.1) as opposed to quantifying how insect populations are changing overall. The take-away is that habitat loss seems to be the primary driver (~50% of declines), followed by 'pollution' (~26%, mostly pesticides and fertilizer), then disease and invasive species (18%) and climate change (7%). That means a sole focus on pesticides will miss key drivers of the problem. Figure 3 has a breakdown by taxonomic order, highlighting that dung beetles are in real trouble.

Photosynthesis in plants relies on an enzyme called RuBisCO, sometimes called 'the most incompetent enzyme in the world' due to its inefficiency and energy loss during respiration. South et al. 2019 present a new transgenic GMO tobacco plant which improves the efficiency of respiration. As a result, their best modified tobacco plants had 41% higher biomass (including 33% more leaf biomass but also larger stems). It's not clear how much of the biomass gain could be translated to improved yields for grains or other crops, but that's still a potentially huge step forward which should be further explored. Eisenhut & Weber 2019 is a nice very short (1.5 page) summary of the article, and you can also read a blog about it here which includes some nice diagrams: https://phys.org/news/2019-01-scientists-shortcut-photosynthetic-glitch-boost.html

REFERENCES:

Anderson, C. M., DeFries, R. S., Litterman, R., Matson, P. A., Nepstad, D. C., Pacala, S., … Field, C. B. (2019). Natural climate solutions are not enough. Science, 363(6430), 933–934. https://doi.org/10.1126/science.aaw2741    

Bradford MA, Carey CJ, Atwood L, Bossio D, Fenichel EP, Gennet S, Fargione J, Fisher JRB, Fuller E, Kane DA, Lehmann J, Oldfield EE, Ordway EM, Rudek J, Sanderman J, Wood SA. 2019. Soil carbon science for policy and practice. Nature Sustainability. http://doi.org/10.1038/s41893-019-0431-y

Burivalova, Z., Allnutt, T., Rademacher, D., Schlemm, A., Wilcove, D. S., & Butler, R. A. (2019). What works in tropical forest conservation, and what does not: Effectiveness of four strategies in terms of environmental, social, and economic outcomes. Conservation Science and Practice, in press(March), 1–15. https://doi.org/10.1111/csp2.28

Catalano AS, Redford K, Margoluis R, Knight AT. 2018. Black swans, cognition, and the power of learning from failure. Conservation Biology 32: 584–596. https://onlinelibrary.wiley.com/doi/abs/10.1111/cobi.13045

Díaz, S., Settele, J., Brondízio, E., Ngo, H. T., Guèze, M., Agard, J., … Zayes, C. (2019). Summary for policymakers of the global assessment report on biodiversity and ecosystem services-unedited advance version. Retrieved from https://www.ipbes.net/news/ipbes-global-assessment-summary-policymakers-pdf and https://ipbes.net/global-assessment

Fisher, J.R.B. and Kareiva, P. 2019. Using environmental metrics to promote sustainability and resilience in agriculture. In Gardner et al. (Eds), Agricultural Resilience: Perspectives from Ecology and Economics. Cambridge University Press. https://www.cambridge.org/us/academic/subjects/life-sciences/ecology-and-conservation/agricultural-resilience-perspectives-ecology-and-economics?format=PB

Grill, G., Lehner, B., Thieme, M., Geenen, B., Tickner, D., Antonelli, F., … Zarfl, C. (2019). Mapping the world’s free-flowing rivers. Nature, 569(7755), 215–221. https://doi.org/10.1038/s41586-019-1111-9

Kennedy, C. M., Oakleaf, J. R., Theobald, D. M., Baruch-Mordo, S., & Kiesecker, J. (2019). Managing the Middle: A Shift in Conservation Priorities based on the Global Human Modification Gradient. Global Change Biology, (June 2018), 1–17. https://doi.org/10.1111/gcb.14549

Li Y, Zhao M, Motesharrei S, Mu Q, Kalnay E, Li S. 2015. Local cooling and warming effects of forests based on satellite observations. Nature Communications 6: 1–8. https://www.nature.com/articles/ncomms7603

Minx JC, Lamb WF, Callaghan MW, Fuss S, Hilaire J, Creutzig F, Amann T, Beringer T, De Oliveira Garcia W, Hartmann J, Khanna T, Lenzi D, Luderer G, Nemet GF, Rogelj J, Smith P, Vicente Vicente JL, Wilcox J, Del Mar Zamora Dominguez M. 2018. Negative emissions - Part 1: Research landscape and synthesis. Environmental Research Letters 13. https://iopscience.iop.org/article/10.1088/1748-9326/aabf9b/meta

Neuenschwander, A., & Pitts, K. (2019). The ATL08 land and vegetation product for the ICESat-2 Mission. Remote Sensing of Environment, 221 (April 2018), 247–259. https://doi.org/10.1016/j.rse.2018.11.005

Oldfield, E. E., Bradford, M. A., & Wood, S. A. (2019). Global meta-analysis of the relationship between soil organic matter and crop yields. SOIL, 5(1), 15–32. https://doi.org/10.5194/soil-5-15-2019

Pohl, C., Krütli, P., & Stauffacher, M. (2017). Ten reflective steps for rendering research societally relevant. GAIA, 26(1), 43–51. https://doi.org/10.14512/gaia.26.1.10

Sánchez-Bayo, F., & Wyckhuys, K. A. G. (2019). Worldwide decline of the entomofauna: A review of its drivers. Biological Conservation, 232(January), 8–27. https://doi.org/10.1016/j.biocon.2019.01.020

South, P. F., Cavanagh, A. P., Liu, H. W., & Ort, D. R. (2019). Synthetic glycolate metabolism pathways stimulate crop growth and productivity in the field. Science, 363(6422), eaat9077. https://doi.org/10.1126/SCIENCE.AAT9077