Thursday, February 12, 2015

Clever Hans: or when horses do math, check your science

My latest blog post is about the challenge of overcoming bias in scientific studies, as illustrated by the wonderful story of Clever Hans, the horse who supposedly could do math and other impressive feats:

Monday, December 22, 2014

Double-blind taste test party

While this is pretty light on the science, we did have a science-esque double-blind taste test party which involved randomly generated numeric labels and a fun decoding step at the end where we found out what we liked and what the odd patterns were. Anyway, our blog post about the experience is here:
and the raw data (without any well-designed charts, sorry) is here:

Friday, September 19, 2014

Reforestation to reduce ozone without costing businesses extra money

A new paper (on which I'm an author) was just published in PNAS on our collaboration with Dow. In particular, we looked at reforestation as a tool for ozone abatement, with the key finding that in Houston reforestation was cost-competitive with building scrubbers (which has a high initial capital cost and cannot readily be adjusted to a precise need for removal) and NOx allowances. If carbon credits could be sold it would be cheaper.

There are plenty of caveats (the legal framework to actually do this is not in place yet, we assume land owners exist who want their lands reforested (as opposed to having to buy land), it only works in places with NOx-limited ozone and ozone non-attainment areas, etc. Also, the national map I made (above) is a coarse analysis showing where this could be replicated, but does not include factors like the current drought in California (the intent is to flag areas deserving a closer look if the policy piece goes through). For the paper, I did a more rigorous habitat assessment about where within the study area a specific type of bottomland hardwood forest could likely be planted successfully.
Nonetheless, it is exciting that in this case we found that a natural solution could be appealing to businesses, while also providing benefits to others (habitat, recreation, etc.). I was only peripherally involved (in the mapping out of where this could work), but I'm still pretty proud.

There is a blog post about why this paper is arguably significant here:

and more details here:

and the actual paper is here:

More information: Reforestation as a novel abatement and compliance measure for ground-level ozone, Timm Kroeger, PNAS, DOI: 10.1073/pnas.1409785111

Read more at:

Monday, June 23, 2014

Do the Rumble-Rump with Peacock Spiders

My latest blog piece is fluff, but still pretty and interesting.
The highlight (other than pics and videos) is that the researchers of one study I refer to documented several key dance moves, including "crunch-rolls," "grind-revs", and "rumble-rumps." And yes, I already have worked out the human equivalent of each, and stand ready to shoot the video once we have critical mass.

Wednesday, June 18, 2014

Global Agriculture Trends: Are We Actually Using Less Land?

A colleague of mine recently alluded to the "rapidly accelerating conversion of natural habitat for agriculture," which got me curious how fast agricultural area was really growing globally. I was pretty surprised to find out that it is actually shrinking! This doesn't mean conversion isn't happening, but it still makes for a pretty interesting story (with a few pretty important caveats). Read about it here:

Here is the map showing where ag land is expanding and where it is contracting:
And for those hesitant to click, here are the other charts:

Some of the most important caveats are: the data has some known issues, we don't have data on how sustainable the increased productivity is, and projected supply is not expected to keep up with projected demand.

The book chapter can be cited as follows for now:
Fisher, J.R.B. and Kareiva, P. Ecosystem-service based metrics of sustainability as tools for promoting conservation and food security. 2014. In Gardner et al. (Eds), Agricultural Resilience: Perspectives from Ecology and Economics. Cambridge University Press. Manuscript submitted for publication.

Saturday, June 14, 2014

Is pollen flammable?

A few weeks ago, there was a post on XCKD's "what if" asking what would happen if all of the pollen on earth was ignited:

As evidence that pollen is actually flammable, the author pointed to youtube videos labeles "burning pollen" but which are actually not of pollen at all. Rather, they are the fluff from cottonwood seeds:

This got me curious: is real pollen also flammable? It is denser so I figured it wouldn't naturally catch on fire to the same degree, but I still wanted to see for myself.

I gathered up a ton of pollen (from red flower carpet rose), and held a lit match against it.

 I did the same thing with sawdust as a reference, as I just had them in a little pile on top of concrete (rather than trying to ignite with a specific dispersal pattern in the air which would have been harder and more dangerous). The idea is that sawdust is accepted to be flammable (or inflammable if you like), even though it may not catch on fire the same way a piece of paper would depending on the conditions. But I figured this would be comparable to what is already online with cottonwood fluff, but for actual pollen (e.g. if a bunch of pollen fell from the flowers and accumulated on the ground). Note that oak catkins or other flower structures don't count as pollen either.

I found that pollen is roughly as flammable as sawdust, perhaps a bit more. Here are the videos:



Here's what the pollen looked like at the end:

Monday, May 12, 2014

Measuring sustainabiilty in agriculture - focusing on outcomes

A white paper I wrote (along with my colleagues Tim Boucher and Samantha Atwood) is now available at:

The basic premise is that the measure whether or not agriculture is truly sustainable we have to get past just measuring practices (what we do, such as conservation tillage or riparian buffers) and move to measuring outcomes (water quality & quantity, soil quality, etc.). We review the literature and suggest several metrics for environmental variables, although we do not include agronomic variables such as yield which are part of overall sustainability.