Monday, November 11, 2019

Soil carbon - what is it good for?

A while back I was on a soil carbon working group with the Science for Nature and People Partnership (SNAPP). Our recent journal article is about soil carbon and soil health. It’s a good read, and only 1,800 words: or if you don't have access.

Pondering soil health

The lead author did a phenomenal job getting the text to be clear and succinct, and the opening two lines actually sum it up very 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: scientists disagree about how effective soil carbon is as a climate change mitigation strategy. We disagree a lot - more than you'd expect. Everything from "this is our best bet to start scaling up now" to "building soil carbon will not result in any net climate mitigation." So we argue about it a lot.

But that debate hides the fact that we generally strongly agree that rebuilding soil carbon is good for farmers and ranchers. Most agricultural soils have lost carbon over time. Regaining it can mean less erosion, better water retention, and better crop resilience to stress. With good management it can even mean less fertilizer use and cleaner water. How much carbon is ideal in different landscapes, and how to best increase it, varies. But it's worth remembering how strong the consensus is on the value of building soil carbon from an agricultural perspective.

Read the paper here: Soil carbon science for policy and practice
There's also a press release here: Building A ‘Solution Space’ for Soil

Monday, November 4, 2019

November 2019 Science Journal Article Summary

Spider at Bodie lighthouse
Happy (belated) Halloween!

This month I'm focused on landscape ecology and climate change (yet again), and unfortunately not spiders or other spooky topics. I also have a webinar on research impact to plug, and a new paper out on the adoption of new practices. As always people can sign up for this newsletter at

Are you a scientist who produces research that you want to have real-world impact? If so, I'll be hosting a session on December 3 (1p EST) with a series of recommendations from a paper that I have in review. You can learn more and register here: and can read the draft paper at

Reddy et al. 2019 (I'm a co-author) looked at the adoption of a new conservation planning framework (Conservation by Design 2.0) being rolled out by The Nature Conservancy. Some staff & teams were early adopters, but it was slow to spread. But people who worked on projects with early adopters from different teams were more likely to use the new practices. Having early adopters work with people from different teams who are slower to change can speed exposure to new ideas and help everyone to learn and adapt. Supervisors should encourage talent-sharing and learning exchanges so this happens more.

Sawyer et al. 2019 looks at how which route animals take during migration impacts their survival. Their key finding was that both their choice of destination ("summer range") and how to get there had a big impact on survival. They found 'exterior' routes (near the edge of the migration corridor) had 30% lower survival compared to interior routes. However - look close at Figure 3 (red means high mortality risk, green low, blue medium). It appears to me that their finding may be an artifact of the fact that mortality is driven by specific destinations, and they didn't report this b/c of how they aggregated summer range boundaries. So it's unclear whether the risk comes from where they go or how they get there.

Tucker et al. 2018 uses GPS data from ~800 animals from 57 mammal species around the world (see Fig 1 for locations) to assess how animals move differently depending on how much humans have modified the landscape (e.g. through buildings, farms, lights, transit, etc.). Unsurprisingly they found more modified areas resulted in significantly less animal movement - especially over time periods of a day or more. They also compared species and confirmed that predators and larger animals tended to move farther, as did animals in resource-poor areas. No big shocks here, but an interesting read.

Tambosi et al. 2014 presents a method to identify priority areas that are highly likely to improve the ecological resilience of a landscape. They look for areas with intermediate resilience - meaning they have decent amounts of habitat and connectivity already, and through targeted restoration they could better connect more intact areas. They then apply this method to the Atlantic Forest in Brazil to identify ~15 million ha of priority areas to reforest (they don't report which subset of that is high vs low priority). It's a relatively simply graph theory approach to connectivity.

Betts 2000 has a point that should be better known. He found boreal forests' ability to mitigate climate change is weak (and may even be negative). Dark needles (present year round) absorb a lot more infrared radiation than typically snow-covered ground. This reduction in albedo (diffuse reflectivity) reduces and in some cases outweighs the carbon sequestration. He compared forest to cropland, but didn't account for N2O emissions from fertilizer.

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.

Fuss et al. 2018 is a look at costs, potential, & side effects from a 3-part series on negative emissions (which they define as reforestation & afforestation, soil carbon, biochar, BECCS, DACCS, enhanced weathering & ocean alkalinization, and ocean fertilization). It has good details for each negative emissions option, but the most useful part for me was Figure 2, which shows the relative contribution needed from 'conventional abatement' (e.g. reducing fossil fuel emissions via clean energy & efficiency, and reducing land use change) vs 'negative emissions' over time.

Betts RA. 2000. Offset of the potential carbon sink from boreal forestation by decreases in surface albedo. Nature 408: 187–190.

Fuss S, Lamb WF, Callaghan MW, Hilaire J, Creutzig F, Amann T, Beringer T, Garcia W de O, Hartmann J, Khanna T, Luderer G, Nemet GF, Rogelj J, Smith P, Vicente JLV, Wilcox J, Dominguez M del MZ, Minx JC. 2018. Negative emissions — Part 2 : Costs , potentials and side effects. Environmental Research Letters 13: 063002.

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.

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

Reddy SMW, Torphy K, Liu Y, Chen T, Masuda YJ, Fisher JRB, Galey S, Burford K, Frank KA, Montambault JR. 2019. How different forms of social capital created through project team assignments influence employee adoption of sustainability practices. Organization & Environment .

Sawyer H, LeBeau CW, McDonald TL, Xu W, Middleton AD. 2019. All routes are not created equal: An ungulate’s choice of migration route can influence its survival. Journal of Applied Ecology 1–10.

Tambosi LR, Martensen AC, Ribeiro MC, Metzger JP. 2014. A framework to optimize biodiversity restoration efforts based on habitat amount and landscape connectivity. Restoration Ecology 22: 169–177.

Tucker MA, Böhning-Gaese K, Fagan WF, Fryxell JM, Van Moorter B, Alberts SC, Ali AH, Allen AM, Attias N, Avgar T, Bartlam-Brooks H, Bayarbaatar B, Belant JL, Bertassoni A, Beyer D, Bidner L, van Beest FM, Blake S, Blaum N, Bracis C, Brown D, de Bruyn PJN, Cagnacci F, Calabrese JM, Camilo-Alves C, Chamaillé-Jammes S, Chiaradia A, Davidson SC, Dennis T, DeStefano S, Diefenbach D, Douglas-Hamilton I, Fennessy J, Fichtel C, Fiedler W, Fischer C, Fischhoff I, Fleming CH, Ford AT, Fritz SA, Gehr B, Goheen JR, Gurarie E, Hebblewhite M, Heurich M, Hewison AJM, Hof C, Hurme E, Isbell LA, Janssen R, Jeltsch F, Kaczensky P, Kane A, Kappeler PM, Kauffman M, Kays R, Kimuyu D, Koch F, Kranstauber B, LaPoint S, Leimgruber P, Linnell JDC, López-López P, Markham AC, Mattisson J, Medici EP, Mellone U, Merrill E, de Miranda Mourão G, Morato RG, Morellet N, Morrison TA, Díaz-Muñoz SL, Mysterud A, Nandintsetseg D, Nathan R, Niamir A, Odden J, O’Hara RB, Oliveira-Santos LGR, Olson KA, Patterson BD, Cunha de Paula R, Pedrotti L, Reineking B, Rimmler M, Rogers TL, Rolandsen CM, Rosenberry CS, Rubenstein DI, Safi K, Saïd S, Sapir N, Sawyer H, Schmidt NM, Selva N, Sergiel A, Shiilegdamba E, Silva JP, Singh N, Solberg EJ, Spiegel O, Strand O, Sundaresan S, Ullmann W, Voigt U, Wall J, Wattles D, Wikelski M, Wilmers CC, Wilson JW, Wittemyer G, Zięba F, Zwijacz-Kozica T, Mueller T. 2018. Moving in the Anthropocene: Global reductions in terrestrial mammalian movements. Science 359: 466–469.



Saturday, October 12, 2019

Paper on what gets people to adopt new practices

I've already mentioned two earlier papers I've published on the adoption of a new conservation planning framework (Conservation by Design 2.0, or CbD 2.0 for short) being rolled out by The Nature Conservancy. Those covered knowledge diffusion and how 'boundary spanners' can increase it. The latest (probably the last) paper from that research is now available here: 

Here's the submitted version of the article (not the nicely formatted one, which you need a subscription for):

This paper is not very accessible to a broad audience, so here's a short summary:
Reddy et al. 2019 looked at the adoption of a new conservation planning framework (Conservation by Design 2.0) being rolled out by The Nature Conservancy. Some staff & teams were early adopters, but it was slow to spread. But people who worked on projects with early adopters from different teams were more likely to use the new practices. Having early adopters work with people from different teams who are slower to change can speed exposure to new ideas and help everyone to learn and adapt. Supervisors should encourage talent-sharing and learning exchanges so this happens more.

That's about it!

Tuesday, October 1, 2019

October 2019 science journal article summary

Monstera deliciosa

This month I focused mostly on climate change. How does the picture above relate? It doesn't, but this fruit rind reminded me of spatial planning hexes which made me smile (bonus points if you can guess the fruit it came from).

If you know someone who wants to sign up to receive these summaries, they can do so at

Last month I sent 10 articles with advice on how to improve the impact of research. Edwards & Meagher 2019 offers a framework you can use to evaluate that impact. I'd recommend focusing on Table 1, which has an excellent list of questions to consider. They can help to better understand what changed (or what you hope will change, since setting impact goals up front is ideal), and how / why it changed (or didn't). The authors argue that conceptual models or results chains (theory of change diagrams) are often useless because sometimes there are interesting feedback loops or non-linear aspects. But while this approach can be flawed and has limits, I've found that situations where it's unhelpful are the exception rather than the rule, and the authors don't make a strong case otherwise. I also didn't find the results where the impact framework was applied to case studies to be very useful, but I really like the questions they asked up front.

Smith et al. 2019 evaluates how six options for greenhouse gas (GHG) removal compare in how well they relate to the Sustainable Development Goals (positively and negatively). They look at reforestation (and afforestation), wetland restoration (coastal and freshwater), soil carbon sequestration, biochar, terrestrial enhanced weathering, and bioenergy w/ carbon capture and storage (BECCS). It's a dense paper worth reading for all the info, especially the figures which are great summaries. One interesting take-away is that restoring wetlands and boosting soil carbon are 'no regrets' strategies with almost entirely positive impacts (although soil as a mitigation strategy has some uncertainty and limits).

Busch et al. 2019 maps where tropical reforestation (and avoided deforestation) is practical at different carbon prices (they report mostly on $20/t CO2e and $50/t). Fig 2 is a great summary of where the most opportunity is. Overall at $20/t they estimate 60.8 Gt CO2e of opportunity (55.1 avoided deforestation, 5.7 reforestation), and at $50/t they estimate 123.4 Gt opportunity (108.3 avoided deforestation, 15.1 reforestation). One interesting finding is that while avoided deforestation is much more cost-effective in general, in 21 countries (mostly African) there is more low-cost opportunity for reforestation. This highlights the need to avoid a one-size-fits-all approach.

There has been considerable discussion on how climate change will impact crop yields. Most predicted impacts are negative (drought stress, less consistent rain, and increasing pests) although some are positive (carbon fertilization, and shifting some marginal lands to be more suitable for crops). Ray et al. 2019 looks at 40 years of global weather data & crop yield data for the top 10 crops, and concludes that those impacts have already started to happen. They estimate that we've probably already lost ~1% of calories we would have had without climate change. Palm oil had the most lost potential, while soy has benefited overall. Check out Figure 1 which maps estimated impacts by each crop around the world.

Roque et al. 2019 is the first test in vivo of the seaweed Asparagopsis to reduce enteric methane from cattle, which is a big deal. The higher dose cut cattle methane emissions per unit of milk by 60% (despite slightly lower weight gain and milk production). Note that all studied cattle were also fed more fiber than usual, which could have increased the size of that effect. More research is needed to: replicate this, look at beef cattle, fully account for GHG changes, and explore impacts on meat and milk quality.

Walsworth et al. 2019 argues that to help species adapt to climate change,  we should focus on protecting a diversity of habitats and genetic differences in populations (plus connectivity between habitat), rather than focusing on 'climate refugia' (colder areas species can move to). This can enable heat-resistant populations to move to other areas where they can interbreed and help other populations adapt. It's a reasonable argument, but note that it's based on a very simple coral reef model. So future work needs to look at this empirically and test it on land and in fresh water.

Realmonte et al. 2019 looked at the global potential impacts of direct air carbon capture and storage (DACCS) tech (splitting out more and less mature versions). They compare scenarios using only reforestation vs. also including bioenergy w/ carbon capture and storage (BECCS) vs. also including DACCS. Their key findings are that having DACCS widely available and effective will help to both meet Paris goals, and to reduce total costs of mitigation. But we can't assume that will happen given the tech challenges and need for investment. In a few places the paper has confusing / misleading language about DACCS allowing delays in mitigation, but elsewhere they make it clear that's not their intent.

Cameron et al. 2017 looks at how much natural habitat can contibute to California's climate goals (~9% of their goals under a moderate scenario). They found the biggest impact from improved forest management to boost C stocks (61% of total potential, from things like longer rotations and higher tree density), followed by reforestation (14%). Some pathways like compost amendments may have undesirable side-effects on biodiversity, and they didn't include other natural climate solutions like changes to agricultural management.

Busch J, Engelmann J, Cook-Patton SC, Griscom BW, Kroeger T, Possingham H, Shyamsundar P. 2019. Potential for low-cost carbon dioxide removal through tropical reforestation. Nature Climate Change 9: 463–466.

Cameron, D. R., Marvin, D. C., Remucal, J. M., & Passero, M. C. (2017). Ecosystem management and land conservation can substantially contribute to California’s climate mitigation goals. Proceedings of the National Academy of Sciences, 201707811.

Edwards, D. M., & Meagher, L. R. (2019). A framework to evaluate the impacts of research on policy and practice: A forestry pilot study. Forest Policy and Economics, (August).

Ray, D. K., West, P. C., Clark, M., Gerber, J. S., Prishchepov, A. V., & Chatterjee, S. (2019). Climate change has likely already affected global food production. PLOS ONE, 14(5), e0217148.

Realmonte, G., Drouet, L., Gambhir, A., Glynn, J., Hawkes, A., Köberle, A. C., & Tavoni, M. (2019). An inter-model assessment of the role of direct air capture in deep mitigation pathways. Nature Communications, 10(1), 3277.

Roque, B. M., Salwen, J. K., Kinley, R., & Kebreab, E. (2019). Inclusion of Asparagopsis armata in lactating dairy cows’ diet reduces enteric methane emission by over 50 percent. Journal of Cleaner Production, 234, 132–138.

Smith, P., Adams, J., Beerling, D. J., Beringer, T., Calvin, K. V., Fuss, S., … Keesstra, S. (2019). Impacts of Land-Based Greenhouse Gas Removal Options on Ecosystem Services and the United Nations Sustainable Development Goals. Annual Review of Environment and Resources, 44(1), 1–32.

Walsworth TE, Schindler DE, Colton MA, Webster MS, Palumbi SR, Mumby PJ, Essington TE, Pinsky ML. 2019. Management for network diversity speeds evolutionary adaptation to climate change. Nature Climate Change 9: 632–636.



p.s. If you'd like to keep track of what I write as well as what I read, I always link to both my informal blog posts and my formal publications (plus these summaries) at

Tuesday, September 3, 2019

September 2019 science journal article summary

Barmini cocktail flight for Jon's 40th birthday (animated gif)

Scientists often have intended uses for their research in mind. Sometimes it works, sometimes it gets ignored, and other times it's used in unexpected ways (like liquid nitrogen being used to make caipirinha sorbet, above).

This month I finally focused on a single topic: how scientists may be able to improve the impact of their research. I'm also working on revising a paper with recommendations along these lines - let me know if you'd like to see the draft.

If you know someone who wants to sign up to receive these summaries, they can do so at

Cairney & Oliver 2018 summarizes 86 publications with recommendations on how scientists may be able to improve their impact (e.g. do high quality research, make it relevant and readable, understand the decision space, build relationships, etc.). They find that the advice is mostly consistent, albeit vague, but they reject that it is either practical or that it will be helpful. They argue that instead the policy theory literature can help more (e.g. highlighting the important of investing in relationships over the long term), and that scientists should also be aware that attempts to increase impact will typically not pay off. They also note that there can be reputational risks in attempting to do so (especially for women and people of color) and that there's inequality in which scientists are in a position to even make the attempt. At the same time, I think they paint a false dichotomy between research that clearly leads to its intended impact, and research that does not. In practice, these steps can likely increase the chance of impact (whether the original intended use or not), and research that ignores all of these recommendations is less likely to be discovered and used.

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.

Jacobs et al. 2005 offers several recommendations for producing science relevant to decision making. They include understanding the decision making context & perspectives of end users of the information produced, building relationships, making the research available and understandable, and providing results that are relevant to potential decisions given constraints (deadlines, resources, scale of action, etc.). They also highlight: the challenges of ensuring equitable outcomes, the importance of 'science integrators & translators' (boundary spanners) to bridge the gap between scientists and others, potential measures of success for collaborations w/ stakeholders, and that all this takes lots of time and is hard to do.

Beier et al. 2017 makes 10 recommendations for actionable science to be co-produced by scientists, decision makers, and others. They include: decision makers should convey their need / problem to scientists (not ask for a product), scientists should understand the decision context before suggesting scientific products, have all partners & stakeholders meet in person, have a small technical advisory group and a steering committee for big complex projects, iteratively discuss assumptions / approaches / etc., decision makers should explain to scientists how they evaluate and manage risk and uncertainty, scientists should honestly convey implications of their research along w/ uncertainty and appropriate use, evaluate the coproduction process itself and share the findings, invest in boundary organizations dedicated to coproduction, and create incentives for academic scientists to engage in coproduction.

Bednarek et al. 2018 defines boundary-spanning (as connecting production and use of knowledge), why it matters, and how to do better at it. They argue that boundary spanner experts (potentially full-time) can improve research impact by serving as honest brokers and facilitating good research design and knowledge co-production. They emphasize that this is about ongoing relationships rather than a 1-way comms 'push.' Table 1 has a list of boundary-spanning orgs, and they give useful details of what boundary-spanners can do. They call for formal boundary-spanning positions, trainings that emphasize the skills needed, and having measures of successful boundary-spanning activities.

Dunn & Laing 2017 interviewed 72 Australian policy makers focused on water managements to ask what aspects of research were most likely to lead to influencing policy outcomes. They didn't prompt them on specific frameworks but summarized open-ended responses. They found the most important aspects were applicability (not only relevant, but solves the right problem w/ the right methods comprehensiveness, timing and accessibility), comprehensiveness (interdisciplinary, applicable to the whole life cycle of a policy process, and including the economic impact of policy), timing (agile enough to meet policy maker deadlines and work fast when opportunity windows open, and willingness to share results early), and accessibility (the audience should be readily able to access and understand the research, meaning it should be short and practical and make clear recommendations). They suggest ACTA as an acronym to capture these four aspects of useful research.

Enquist et al. 2017 is an overview of 'translational ecology' which they define as integrating ecological knowledge with decision making. Similar to calls for transdisciplinary research, the idea is for researchers to work with decision makers and stakeholders throughout the process and focus on real-world outcomes. They lay out 6 key principles (collaboration, engagement, commitment, communication, process, and decision-framing) and give examples of each in Panel 2. Panel 1 has a useful summary of relevant terms / jargon which can be confusing to folks new to this topic.

Wall et al. 2017 is another overview of translational ecology.  They focus heavily on the need for scientists to engage in building relationships and trust with decision makers and other stakeholders.

Ruhl et al. 2019 asked  which kinds of scientific papers are the most relevant to policy (clearly articulating a policy proposal, policy actors, and actions to implement it). They limited it to 220 papers published in Policy Forums in Science magazine in the last five years. The most interesting finding is that paper with the most policy relevance cited the most other papers but were cited the least often, indicating that papers aimed at decision makers may be of less interest to research scientists (Fig 3). See Fig 1 for how different fields rated in policy relevance (e.g. atmospheric & hydrospheric science had the highest rate of medium and high policy relevance, general interest articles had the lowest).

Salafsky et al. 2019 is a guide for conservation practitioners to define, generate, and use evidence. They offer a typology of different kinds of evidence (and different contexts where each may be most appropriate, see Tables 2 and S1), plus a decision tree to help choose how to use evidence in a given context (Figure 2). They close with a call to incorporate thoughtful use of evidence into conservation practice, learning from disciplines like medicine which have been doing so for longer.

Bednarek, A. T., Wyborn, C., Cvitanovic, C., Meyer, R., Colvin, R. M., Addison, P. F. E., … Leith, P. (2018). Boundary spanning at the science–policy interface: the practitioners’ perspectives. Sustainability Science, 13(4), 1175–1183.

Beier, P., Hansen, L. J., Helbrecht, L., & Behar, D. (2017). A How-to Guide for Coproduction of Actionable Science. Conservation Letters, 10(3), 288–296.

Cairney, P., & Oliver, K. (2018). How Should Academics Engage in Policymaking to Achieve Impact? Political Studies Review.

Cameron, D. R., Marvin, D. C., Remucal, J. M., & Passero, M. C. (2017). Ecosystem management and land conservation can substantially contribute to California’s climate mitigation goals. Proceedings of the National Academy of Sciences, 201707811.

Dunn, G., & Laing, M. (2017). Policy-makers perspectives on credibility, relevance and legitimacy (CRELE). Environmental Science and Policy, 76(February), 146–152.

Enquist, C. A., Jackson, S. T., Garfin, G. M., Davis, F. W., Gerber, L. R., Littell, J. A., … Shaw, M. R. (2017). Foundations of translational ecology. Frontiers in Ecology and the Environment, 15(10), 541–550.

Jacobs, K., Garfin, G., & Lenart, M. (2005). More than Just Talk: Connecting Science and Decisionmaking. Environment: Science and Policy for Sustainable Development, 47(9), 6–21.

Pohl, C., Krütli, P., & Stauffacher, M. (2017). Ten reflective steps for rendering research societally relevant. GAIA, 26(1), 43–51.

Realmonte, G., Drouet, L., Gambhir, A., Glynn, J., Hawkes, A., Köberle, A. C., & Tavoni, M. (2019). An inter-model assessment of the role of direct air capture in deep mitigation pathways. Nature Communications, 10(1), 3277.

Roque, B. M., Salwen, J. K., Kinley, R., & Kebreab, E. (2019). Inclusion of Asparagopsis armata in lactating dairy cows’ diet reduces enteric methane emission by over 50 percent. Journal of Cleaner Production, 234, 132–138.

Ruhl, J. B., Posner, S. M., & Ricketts, T. H. (2019). Engaging policy in science writing: Patterns and strategies. PLOS ONE, 14(8), e0220497.

Salafsky, N., Boshoven, J., Burivalova, Z., Dubois, N. S., Gomez, A., Johnson, A., … Wordley, C. F. R. (2019). Defining and using evidence in conservation practice. Conservation Science and Practice, 1(5), e27.

Wall, T. U., McNie, E., & Garfin, G. M. (2017). Use-inspired science: making science usable by and useful to decision makers. Frontiers in Ecology and the Environment, 15(10), 551–559.



p.s. If you'd like to keep track of what I write as well as what I read, I always link to both my informal blog posts and my formal publications (plus these summaries) at

Thursday, August 1, 2019

August 2019 science journal article summary

Photo from Mick Garratt


Hot weather and a vacation in the woods have me thinking about climate change and habitat conversion (with articles on deforestation, landscape conservation, biodiversity, and livestock sustainability).

If you know someone who wants to sign up to receive these summaries, they can do so at

Runting et al. 2019 argues that debates about 'land sparing' vs 'land sharing' miss an important point - good forest management is likely more important. They run several scenarios with different degrees of land sharing vs sparing, and conventional vs. improved management (reduced-impact logging, longer plantation rotation, and strictly enforcing protected areas). They saw the best outcomes with improved management and a mix of sparing and sharing (but favoring sparing, see Figure 4). Check out Figure 2 for what an 'optimal' scenario looks like compared to extreme sharing or sparing (but ignore the idea that tiny islands of protected areas or holes in larger ones are ideal - this is almost certainly an artifact). There's a blog on this one at

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 and you can download the data from

Bastin et al. 2019 estimate 900 million ha of land could be reforested globally (excluding cropland and urban areas), which could store 205 Gt of carbon (752 Gt CO2e). Alternatively, they predict we'll lose 223 million ha of forest by 2050 under business as usual. This paper has been broadly criticized for overstating the role of reforestation in climate mitigation (while reforestation is important, the authors' conclusion that it's the most important solution is a fringe opinion), especially since they call for a focus on boreal plantings which reduces albedo relative to bare snow and ice (thus reducing the climate mitigation contribution). Here's a blog covering the paper including the critique:

Diaz et al. 2018 looks at trade-offs between different forest management options for Douglas-fir in the NW US that could improve carbon storage. They compare managing the land to optimize net present value (NPV) to managing for sustained timber yield (with different levels of environmental management, e.g. longer rotations and some aspects of FSC certification). They find that environmental constraints boost carbon storage but hurt net present value. For example, one scenario had 26% more carbon, but 15% less timber and 21% lower NPV. They explore different policy options and challenges related to driving more carbon storage in timberlands.

Lambin et al. 2018 look at how effective company commitments to end deforestation are. The key finding is that public policy can significantly improve the likelihood of reducing deforestation relative to private action alone. For example, the Soy Moratorium combined sector-wide commitments with monitoring and public disincentives to clear forest in Brazil, with some success. They call for better company commitments (as called for by the Accountability Framework,, and recommend public policies including: legal reform & enforcement, land tenure reform, working with people clearing the most forest, broadening scope (companies, commodities, & regions), incentivizing all actors in the supply chain to participate (e.g. fertilizer companies rarely engage in these commitments), improving traceability and transparency, and increasing demand for deforestation-free products.

Schader et al. 2015 looks at how shifting what we feed cattle could improve sustainability. The idea is to feed them less food humans could eat (like corn), and more grass and by-products we can't or don't eat (e.g. distiller's grains, bran, oilseed cake, etc.), which also limits the total amount of livestock which can be raised in this way. Figure 1 is a great overview of what this would mean, for example a big reduction in pigs and chicken and only modest increases in other livestock (that can eat grass). But note a cardinal data visualization sin: inconsistent scaling of bar charts (e.g. the soil erosion from water chart makes it look like their preferred scenario has only 42% the erosion of the reference scenario, but it actually has 88% the erosion) which means you have to look carefully. Still, it's an important concept to explore, and a useful contribution to the conversation.

What are the barriers to using livestock practices that reduce GHGs? Kipling et al. 2019 asked Welsh ranchers and other stakeholders in a series of interviews and workshops. They focused on the conceptual framework rather than the practices, splitting them into practical limitations (e.g. costs and infrastructure, see Figure 1), knowledge limitations (being unaware of options and how they work, see Figure 2), and cognitive limitations and interests (complexity and competing values, see Figures 3 & 4). There aren't any big surprises here, but it's a useful overview, especially the quotes from ranchers for each concept they present.

Humphreys et al. 2019 looks at recent (since 1900) and historic plant extinction, and compares it to animal extinctions. The most interesting findings are that the IUCN Red List data on extinct plants are pretty poor (with 50 Red List species incorrectly listed as extinct, and 491 extinct species missing from the Red List), that 54% of plants reported extinct were later rediscovered (or reclassified to be the same as an extant species), that thousands of extant plant species are 'functionally extinct' (too few exist to form a viable population going forward), and that 55% of the 571 plant species that have gone extinct have done so since 1900. This is a short paper and worth reading.

Bastin, J.-F., Finegold, Y., Garcia, C., Mollicone, D., Rezende, M., Routh, D., … Crowther, T. W. (2019). The global tree restoration potential. Science, 365(6448), 76–79.

Diaz, D. D., Loreno, S., Ettl, G. J., & Davies, B. (2018). Tradeoffs in timber, carbon, and cash flow under alternative management systems for Douglas-Fir in the Pacific Northwest. Forests, 9(8), 1–25.

Humphreys, A. M., Govaerts, R., Ficinski, S. Z., Nic Lughadha, E., & Vorontsova, M. S. (2019). Global dataset shows geography and life form predict modern plant extinction and rediscovery. Nature Ecology & Evolution, 3(July).

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.

Kipling, R. P., Taft, H. E., Chadwick, D. R., Styles, D., & Moorby, J. (2019). Challenges to implementing greenhouse gas mitigation measures in livestock agriculture: A conceptual framework for policymakers. Environmental Science and Policy, 92(November 2018), 107–115.

Lambin, F., Gibbs, H. K., Heilmayr, R., Carlson, K. M., Fleck, L., Garret, R., … Walker, N. (2017). The role of supply-chain initiatives in reducing deforestation. Nature Climate Change, 8(February), 109–116.

Runting, R. K., Ruslandi, Griscom, B. W., Struebig, M. J., Satar, M., Meijaard, E., … Venter, O. (2019). Larger gains from improved management over sparing–sharing for tropical forests. Nature Sustainability, 2(1), 53–61.

Schader, C., Muller, A., El-Hage Scialabba, N., Hecht, J., Isensee, A., Erb, K. H., … Niggli, U. (2015). Impacts of feeding less food-competing feedstuffs to livestock on global food system sustainability. Journal of the Royal Society Interface, 12(113).



p.s. If you'd like to keep track of what I write as well as what I read, I always link to both my informal blog posts and my formal publications (plus these summaries) at

Monday, July 1, 2019

July 2019 science journal article summary

      Above: People floating down the river Rhine, see rivers articles below


Here is another grab bag of articles on landscape conservation, research impact, rivers, climate change, and coastal wetlands. If you know someone who wants to sign up to receive these summaries, they can do so at

Once again Steve Wood (from The Nature Conservancy) has kindly added a couple of his own guest reviews, which I've broken out below to avoid confusion. Thanks Steve!

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.

White et al. 2019 surveyed land managers from the U.S. Forest Service about how they received and used scientific information in decision making. One key finding is that they believe science is less useful in making decisions with high public consensus (although even then only 19% of managers thought public priorities should have more weight than science, with 36% wanting equal weight and the remainder giving more weight to science, see Figure 3a). This study also reports low engagement with scientists, but Figure 1 shows that they primarily measured managers actively seeking out scientists rather than the reverse (which could be more common).

Bogenschneider et al. 2019 interviewed legislators in WI and IN about how research contributes to policymaking. While research was only infrequently mentioned as changing or even informing their positions on issues, it was seen serving several purposes (see Table 1), including persuading others, designing good legislation, educating others, improving debate & dialogue, and building trust. However, several quotes imply that they tend to seek out research that backed up their beliefs rather than exploring with an open mind. At the same time, the results highlight the importance of clear scientific conclusions that allow legislators to evaluate the potential impacts of actions they're considering (as opposed to more circuitous findings sometimes favored by scientists).

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.

Cui et al. 2016 estimates how sediment built up behind Matilija dam would be released after dam removal (or partial removal / breach). They conclude that upon removal the main sediment pulse is likely to only last a few hours, and almost certainly < 3 days (with a worst case scenario of 8 days). The authors then argue that halting water diversion (e.g. for agriculture) until the sediment stabilizes should have minimal impact given the short time for sediment to be flushed out.

Gonzalez 2018 is an unsurprising but interesting reframing of current and projected climate change impacts: national parks are harder hit than the rest of the US (getting warmer and drier). This is largely driven by the fact that 63% of national park area is in Alaska (!), with most of the rest in the Western US (see Figure 2). This shows the need for parks to be actively planning how to respond to climate change, and is a useful reminder that protected areas are not protected from climate change.

Renzi et al. argues that to successfully restore coastal wetlands, reducing stress & competition isn’t enough. To make restoration more effective at replicating intact habitat we should incorporate ‘positive species interactions’ (where one or both organisms benefits from the other without being harmed, aka ‘symbiosis’ in lay terms but in ecology symbiosis has a broader meaning). Examples include clumps of seagrass helping each other by capturing more nutrients and reducing erosion, or sponges on mangrove roots exchanging nutrients and carbon so both grow faster (See Fig 1 & 2 for more examples). Key recommendations are :to clump (not evenly space) plantings of seagrass or mangroves (in most but not all cases, context is important),  introduce a diverse set of plants and animals (rather than hoping for colonization later), and consider proximity to other wetlands.

Guest reviews from Steve Wood:

Many environmental groups have focused on using natural ecosystems to drawdown carbon dioxide to achieve climate goals. Baldocchi & Penuelas 2019 walks through the science of how that drawdown works. They cover the mechanistic science of limits to plant fixation of carbon, but in an extremely accessible way. Although they write from a neutral perspective, there are hints of doubt that drawdown could be achieved at scale to have climate-relevant impacts.

Herbicide residues from widespread chemical weed management can have negative impacts on terrestrial and aquatic ecosystems. Combined with herbicide resistance and lack of innovation of new herbicides has led people from corporations to ecologists to advocate for ecological approaches to weed management. Barberi 2019 gives an overview of ecological weed management approaches, with a lens on sub-Saharan Africa. They focus specifically on practices to: reduce weed seedling emergence; improve crop competitiveness; and reduce weed seedbank size. There is a particular emphasis on Striga management. This is a very thorough literature survey and would be a great entry point to understanding the literature. They do not, however, quantitatively synthesize the literature through tools like formal meta-analysis to put numbers to the impact of practices.

Baldocchi, D., & Peñuelas, J. (2019). The physics and ecology of mining carbon dioxide from the atmosphere by ecosystems. Global Change Biology, 25(4), 1191–1197.

Bàrberi, P. (2019). Ecological weed management in Sub-Saharan Africa: Prospects and implications on other agroecosystem services. In Advances in Agronomy (1st ed., Vol. 156).

Bogenschneider, K., Day, E., & Parrott, E. (2019). Revisiting theory on research use: Turning to policymakers for fresh insights. American Psychologist.

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.

Cui, Y., Booth, D. B., Monschke, J., Gentzler, S., Roadifer, J., Greimann, B., & Cluer, B. (2016). Analyses of the erosion of fine sediment deposit for a large dam-removal project: an empirical approach. International Journal of River Basin Management, 15(1), 103–114.

Gonzalez, P., Wang, F., Notaro, M., Vimont, D. J., & Williams, J. W. (2018). Disproportionate magnitude of climate change in United States national parks. Environmental Research Letters, 13(10), 104001. Retrieved from

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.

Renzi, J. J., He, Q., & Silliman, B. R. (2019). Harnessing Positive Species Interactions to Enhance Coastal Wetland Restoration. Frontiers in Ecology and Evolution, 7(April), 1–14.

White, E. M., Lindberg, K., Davis, E. J., & Spies, T. A. (2019). Use of Science and Modeling by Practitioners in Landscape-Scale Management Decisions. Journal of Forestry, 117(3), 267–279.



p.s. If you'd like to keep track of what I write as well as what I read, I always link to both my informal blog posts and my formal publications (plus these summaries) at