Author: Haley Catton
Last year I had the pleasure of spending 3 months in the Buckley Plant Ecology Lab as a visiting PhD student from the University of British Columbia Okanagan in Canada. I am studying and modeling population-level effects of weed biocontrol and nontarget attack, so visiting the Buckley lab was a natural fit. My study system is the trio of the nasty rangeland weed, houndstongue (Cynoglossum officinale) (Photo 1), its effective root-feeding biocontrol weevil Mogulones crucifer (Photo 2), and the native nontarget plant blue stickseed (Hackelia micrantha) (Photo 1). The weevil, approved for release in Canada in 1997, strongly favours its target weed, but will also use the nontarget plant.
Photo 1. Haley holding specimens of the invasive weed, houndstongue. Photo 2. Weevil attacking the nontarget plant, blue stickseed.
So the question is, is the native nontarget plant at risk from the weevil? To investigate, I’ve got a field experiment running on beautiful rangeland in western Canada (Photo 3), where I am following the demography of houndstongue and nontarget plant populations near and far from insect release sites. I came to Dr. Buckley’s lab in September 2010 with two field seasons’ demographic data and a huge list of questions on how best to work with them.
Photo 3. Assistants at Haley’s field site in western Canada
My time in the lab was very productive and informative. I learned how to compile my data, worked with the (dreaded) analysis software R, built matrix models and performed generalized linear mixed effects models on my data.
Preliminary analyses are helping me understand how the weed and nontarget plants behave on a population level. For example, houndstongue appears to have density-dependent mortality at the vegetative stage, but not the reproductive stage. Not surprisingly after just one year, the effects of the biocontrol insect on its weed are inconclusive so far. As well, no effect on the nontarget plant has been found. However, I still have another field season of data collection to go, so things may clear up in the next year or so. Stay tuned!
In short, thanks to the Buckley Plant Ecology Lab, I learned a whole lot about demographic data analysis and mixed effects models, and resources to get more information on these tools. This is in addition to meeting wonderful professional connections and friends, and of course spending time in beautiful Queensland. I also learned that Aussies will take off an entire afternoon to watch a 3-minute horse race (Melbourne Cup), and they would rather re-play an entire Grand Final football game instead of settling it in overtime. Good times!