Ecologist’s Diary with Gesche Blume-Werry: Earthworms on the loose

Lately, I have been working on setting up a new (and really fun!) experiment. There is something to say about setting up a new experiment, while one is moving to a new job (‘don’t do it’, for example), but it has been really exciting despite the logistic puzzle.

Collected earthworms. Will they like the tundra as much as the boreal forest/mires/agricultural soils?
Collected earthworms. Will they like the tundra as much as the boreal forest/mires/agricultural soils?

The experiment is about consequences of earthworm invasion into different tundra communities in the Subarctic. Earthworms are powerful ecosystem engineers that can strongly alter ecosystem processes, such as carbon and nutrient cycling, and vegetation composition. Most of the work on invasions of geoengineering earthworms, such as Lumbricus or Aporrectodea species, has been done in North America, where those worms have been introduced by humans and successfully invaded novel habitats. But these worms are not (yet) present in tundra in Fennoscandia, and little work has been done on the impacts of potential invasions there. Probably because no one thought they would be coming this way, but there is some recent evidence that they might be…

A last glimpse before they burrow themselves in. Goodbye little worms, go and geoengineer!
A last glimpse before they burrow themselves in. Goodbye little worms, go and geoengineer!

So, we decided to study what happens to tundra in the presence of these geoengineers. My work has a very strong plant (root) focus, so working with worms is a novelty for me. Luckily, I have great colleagues, some of them more and some less familiar with worms, and we are working on this as a group effort. I am also very grateful that besides the big funding agencies, there are several smaller research foundations in Sweden (in our case the Göran Gustafsson foundation). It’s so helpful for early career researchers, and makes projects like this one (a side project for all persons involved, but with the potential for very important results) possible. And even though, or maybe because, many of us are a tad out of their comfort zone, this is a lot of fun. We put worms into tundra mesocosms in the common garden at the Abisko Scientific Research station, and will measure their impacts on a variety of response variables. Including roots, of course! Working with roots means that I am used to studying things hidden from plain view, but it was still a bit sad to lose sight of the worms immediately after we put them in. So right now, there is just no way of knowing what the worms do down there. Or is there…

Earthworms hidden below.
Earthworms hidden below.

To study root dynamics, I am using minirhizotrons which provide a ‘window’ into the soil through a video camera system in a transparent, buried plastic tube. During a root sampling, I actually spotted one of the worms burrowing away just at the tube surface giving me a glimpse into worm life. It seemed happy enough, so I am curious to see what the plants and greenhouse gas fluxes will have to say about it!

More soon,

Gesche

Gesche Blume-Werry, @gescheBW Umeå Univerity, Sweden & University of Greifswald, Germany

Read more Ecologist’s Diary or more posts by Gesche.

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