Friday, March 1, 2019

Transition for monthly science updates


As many of you have heard, this is my last day at The Nature Conservancy; I'll be taking a new job at The Pew Charitable Trusts on their conservation science team. I don't know yet what will happen with these summaries but don't despair! I hope to keep them going in some form - likely with a different topical focus. If you know someone who is feeling lucky and wants to sign up to receive these summaries despite the uncertainty, they can do so at

I've been frantically wrapping up work so have read less science than usual this month. But I did write a blog post explaining why seemingly silly questions like how to define forests and deforestation are actually both tricky and really important: How many trees make a forest? I talk about The Accountability Framework and the critical role it can play in helping to end deforestation:

The only papers I reviewed this month are one about how scientists read scientific literature, and two soil papers (from TNC's Deborah Bossio and Steve Wood) which are both summarized on this blog:

Colleagues working in applied conservation often tell me they have no time to read scientific literature. Tenopir et al. 2015 is an article about how faculty in five US universities seek out scholarly literature (including but not limited to the sciences)! I'll be honest - I skimmed this looking for two bits of information: scientists reported reading an average of 26 articles per month (Fig 1), and spent 32 minutes on each article (Fig 2). I read fewer articles, and usually read them faster. But even these academics are spending less than two days out of the month on this. Surely most of us can find a few hours! There are some other interesting tidbits here. Almost 2/3 of articles read are from the last two years - so have a good comms plan for your research! Also, NONE of the surveyed scientists read articles on a mobile device like a tablet, which is a huge missed opportunity for those long commutes on mass transit!

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.

Vermeulen et al. 2019 is a call to action on improving global soil carbon stocks. It reviews some of the challenges that have impeded action at scale,and emerging opportunities that could give soil initiatives a boost. They call out three key needs, and look at possible actions to advance all three. First, a compelling vision for action led by political champions. Second, a stronger business case (including evidence of success for both public and private investors). Finally: a more compelling value proposition for farmers and land managers. They also highlight the need for practical measurement protocols, and several policy gaps. It's a quick read at 3 pages so worth a look.

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, 13–32.

Tenopir, C., King, D. W., Christian, L., & Volentine, R. (2015). Scholarly article seeking, reading, and use: A continuing evolution from print to electronic in the sciences and social sciences. Learned Publishing, 28(2), 93–105.

Vermeulen, S., Bossio, D., Lehmann, J., Luu, P., Paustian, K., Webb, C., … Warnken, M. (2019). A global agenda for collective action on soil carbon. Nature Sustainability, 2(1), 2–4.



p.s. as a reminder, you can search all of the science articles written by TNC staff (that we know of) here
(as you publish please email to help keep this resource current). This will be my last plug for this resource since I'm leaving TNC.
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