Genetic Diversity and Ecosystem Functioning

Newmarket, ON

This summer, I’ll be collecting tissue samples from individual plants in old field communities. I’ll use RAD sequencing to determine genetic diversity within each species in these communities. By measuring the total biomass in the communities, I’ll be able to look for relationships between genetic diversity and productivity. We’ll also be measuring several functional traits on these plants and determining their evolutionary relationships to each other in order to estimate the functional and phylogenetic diversity of each community. I’ll be doing this work in collaboration with several members of the Cadotte Lab and we’ll be working at the Koffler Scientific Reserve, just north of Toronto.

Tundra Respiration in the Arctic

Toolik Lake, AK

collaborators: Owen Atkin, Syndonia Bret-HarteDan Flynn, Kevin Griffin, Anja Kade, Adrian Rocha, Gaius Shaver, Matthew Turnbull

In 2007 and 2008 I travelled to the arctic Long Term Ecological Research site at Toolik Lake, AK to measure the effect of 24-hour sunlight on plant respiration. Respiration is often measured in the dark, since it is confounded with photosynthesis in daylight. Though little is known about rates of respiration in light, they are often assumed to be negligible due to light inhibition. In the Arctic, plants receive constant daylight during much of their growing season and may therefore be adapted to these conditions. I used the Kok method, which uses gradually decreasing light levels to measure respiration in the light, to determine the extent of inhibition by light. These measurements were made on individual plants as well as at the ecosystem scale using eddy covariance towers. This work should help improve estimates of Arctic carbon stocks and indicate how these stocks may change over time under climate change scenarios.