Thursday, March 1, 2018

March 2018 Science Journal Article Summary


It has been a hectic month so I haven't read much science. I'm including two articles on beef sustainability (one exciting case study, and one much broader review), as well as a new paper of mine that was finally published after an epic 14 month review. My paper looks at how information about CbD 2.0 spread within TNC and beyond, and while it's long and dense I'd encourage you to at least check out the summary below for tips on how to aid "knowledge diffusion" and how to study it.

Stanley et al. 2018 is a paper arguing that proper grazing management may be able to make beef a net carbon sink. They don't go quite that far, but it's a reasonable extrapolation. While this is an encouraging case study and we should look carefully at how to apply it, there are some really important caveats to interpreting this more broadly. Specifically, they found using "adaptive multi-paddock (AMP)" grazing for the finishing phase of cattle instead of feeding them grain resulted in a sink of ~6.7 kg CO2e / kg carcass weight, compared to a source of ~6.1 kg CO2e / kg for feedlot beef. The study is designed well, and soil C improvements were measured empirically over 4 years, in three types of soil in the Upper Midwest. That being said, there are a few big issues that challenge the narrative of "carbon positive beef" being possible at wide scales:
  1. The soil sequestration here (3.6 Mg C / ha / yr) is much higher than is typically reported (although some studies have shown similar rates).
  2. These rates would diminish over time; it's not clear how fast the soil would saturate but high rates like this would be most likely in early years after improving management of highly degraded soils.
  3. This study was on alfalfa pasture (which fixes N); it's unlikely these results would apply to unfertilized rangelands
  4. The study did not include soil nitrous oxide emissions which are often substantial in leguminous pastures.
  5. Finally, the grass-finished beef took up twice as much space as the feedlot beef. That could be good from a perspective of prevent conversion of grasslands by keeping them in production, but it also means that if we scaled up grass-finished beef at this density, we'd have to find twice as much land to graze cattle on, which could drive conversion. It would also likely raise costs for producers and consumers.

Garnett et al. 2017 ("Grazed and Confused") is a very thoughtful review of the climate change / GHG impact of ruminants (largely cattle). Their first key findings is that even with good grazing ruminants still have high net GHG emissions. They also note sequestering soil carbon often has trade-offs with methane and nitrous oxide. Finally, as demand for animal protein rises sharply there is likely to be both land conversion and increasing GHGs as a result. These have all been reported widely in other studies, but it's a nice summary. On the one hand, it's hard to pull out quantitative results from this paper. On the other, it does a great job of covering the various arguments and counterpoints around cattle and carbon, and presenting the data in a value-neutral tone. Anyone interested in this topic should at least skim the 8-page summary.

Fisher et al. 2018 ("Knowledge diffusion within a large conservation organization and beyond") looks at how people find information about innovations and share them, specifically the spread of Conservation by Design 2.0 (CbD 2.0). We review how earlier versions of CbD spread from TNC (looking at published science articles and expert interviews), then use tons of varied data to look at CbD 2.0. I wrote a blog about the paper here:
and the full paper is at:
but here's a summary of what we learned:
  1. Sending repeated broadly-targeted communications (e.g. all-staff email / newsletters / etc.) that make it easy for recipients to find out more worked better than more narrowly focused communications (e.g. plenary talks, emails from executives).
  2. Expert interviews revealed several factors to promote diffusion: bringing in partners early to develop and test methods, committing up front to sustain support for the planning methods, having in-person workshops, using peer-review and shared learning, providing financial support, explaining how the methods address existing needs planners already have, and the existence of a support and learning network like the conservation coaches network (CCNET). 
  3. Organizations may wish to use internal data to identify staff likely to play a key role in diffusing so that they can encourage that process (the paper has details on how, with more forthcoming in an upcoming paper)
  4. Working with academics on publications represents a potential way to get the word out with relatively low effort for organizations (academics I have worked with in other contexts are often very interested in data no one else has access to, and have published cool papers from those data). 
  5. For scientists interested in this topic, we learned a lot about how to study knowledge diffusion, and share tips for researchers (e.g. thinking about image-blocking, legal and privacy constraints, distinguishing internal and external website visits, etc.).

Fisher, J. R. B., Montambault, J., Burford, K. P., Gopalakrishna, T., Masuda, Y. J., Reddy, S. M. W., … Salcedo, A. I. (2018). Knowledge diffusion within a large conservation organization and beyond. PLoS ONE, 13(3), 1–24.

Garnett T., Godde C., Muller A., Röös E., Smith P., de Boer I.J.M., Ermgassen E., Herrero M., van Middelaar C., Schader C. and van Zanten H. (2017). Grazed and confused? Ruminating on cattle, grazing systems, methane, nitrous oxide, the soil carbon sequestration question. Food Climate Research Network, University of Oxford

Stanley, P. L., Rowntree, J. E., Beede, D. K., DeLonge, M. S., & Hamm, M. W. (2018). Impacts of soil carbon sequestration on life cycle greenhouse gas emissions in Midwestern USA beef finishing systems. Agricultural Systems, 162(November 2017), 249–258.

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