Hey, Dan Ackerman here! I arrived in Sweden at the beginning of July prepared to study nutrient cycling in the fungal community. The plan was to collect samples of ectomyccorhizal mushrooms that form symbiotic relationships with plant roots, helping them access various goodies from the soil, such as phosphorus and certain forms of nitrogen, both vital plant macronutrients. However, a number of unfortunate factors made such a study an impossible dream. Last winter was a particularly harsh one in Northern Scandinavia. The snow melted later than usual, meaning mushrooms are not ready to fruit quite this early in the season. Additionally, an extremely severe outbreak of Northern Autumn Moth (Epirrita autumnata) caterpillars in the region this year has led to decreased plant production, which means the fungi are missing a large part of their carbon source, from which mushrooms would be formed. It was definitely a disappointment at first, but these things happen in field work.
So, in a crazy plot twist, I’ve decided to study the “diet” of Pinguicula vulgaris (A.K.A. the common butterwort), a carnivorous plant common in moist areas around Abisko. These little meat-eaters grow on bare ground in poor soils where no other plants dare to colonize. Their leaves, comprising a jaundiced-looking rosette laid flat on the ground, secret a sticky enzyme stew (good with rosemary or plain) that traps and digests insects with poor luck and those that have become fed up with living in such a harsh climate. To be honest, P. vulgaris is the ugliest plant known to science when it’s not flowering, but I find it to be among the most interesting, due to its alternative lifestyle.
I’ve been gathering samples from two contrasting habitat types: moist sphagnum and sub-alpine heath. For each plant I collect, I will use a mass spectrometer to determine the nitrogen isotopic ratio for the bugs trapped in the leaves, the leaves themselves, the roots, and the soil in which the specimen is growing. Depending on how closely the isotopic signature of the plant parts matches that of either the bugs or the soil, I will be able to estimate what percent of the plant’s nitrogen is acquired from insect consumption versus uptake from soil nitrogen pools. I am interested in finding out whether the degree of carnivory differs significantly between plants growing in the two different habitat types. There hasn’t been much prior research on this topic, so I can’t wait to find out the results once we get back to New Hampshire. In the meantime, I’ll be here in Sweden squatting in bogs to pick partially-digested bugs off of plant leaves. Oh, the glory!