Tree trunks, game theory, and the invisible hand

Image: Me, collecting foliage from balsam fir trees in Quebec.  Photo courtesy Cameron Rugo.

Last month I spent a week in the field, as part of a team collecting soils and foliage for a project assessing carbon sequestration in spruce budworm-defoliated forests*. The soil was always easy to reach, conveniently located right at ground level (funny how that works, isn’t it?) – but the foliage, not so much. As is true in forests the world around, the bulk of the foliage is way, way up in the air. That pole I’m wielding in the photo above? It’s a “pole pruner”, and it has a cutting head at the end of a series of interlocking pole segments – seven segments in the photo, which means I’m balancing a wobbly, bendy pole and manoeuvering it through snags and branches to snip samples about 12 metres (40 feet) from the ground. This is hard, and as I was doing it I found myself thinking that the whole thing would be simpler if the trees could just get their act together and grow at bush height.

Now, that’s pretty stupid thing to think, I admit; but it’s also an interesting thing to think.

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Are two years’ data better than one?

Photo: Two giraffes by Vera Kratochvil, released to public domain, via publicdomainpictures.net. Two giraffes are definitely better than one.

Ecologists are perennially angst-ridden about sample size.  A lot of our work is logistically difficult, involves observations on large spatial or temporal scales, or involves rare species or unique geographic features.  And yet we know that replication is important, and we bend over backwards to achieve it.

Sometimes, I think, too far backward, and this can result in wasted effort.

The joys of other people’s field work

Photos: Pulling in a gill net in Vatnshlíðarvatn; and a male arctic charr in spawning colour (S. Heard).

I’ve just come back from gill-netting arctic charr in Vatnshlíðarvatn, a small, shallow lake just west of Varmahlíð in northern Iceland. The charr in this lake are a pair of morphs (a diet specialist and a diet generalist), and the aim was to collect fish of each morph for stable isotope and genetic analysis. It was a sunny July morning (about 7 ºC, which isn’t bad for Iceland), the fish were beautiful, and I enjoyed the work thoroughly.

Those of you who know me are, by now, smelling a rat: I don’t work on fish.