Thursday, 30 May 2019

2019 Alexandra Fiord field season

In a couple of days time I will be wending my way northwards for a second year of field work at Alexandra Fiord on Ellesmere Island, Nunavut. We will be flying from Ottawa to Resolute via Iqaluit, Pond Inlet and Arctic Bay and staying at the Polar Continental Shelf Program facilities in Resolute until the weather looks good to fly the two hours north east on a Twin Otter plane to Alexandra Fiord. We have no internet at the field site but I have an inReach Iridium satellite device so you can check out my MapShare to get updates on where I am and what I am doing!

RCMP buildings at Alexandra Fiord, Ellesmere Island, Nunavut, Canada
Our field site is based at the old Alexandra Fiord RCMP post built in 1953. Field work plots were established in 1992 in the valley behind the post to study the effects of climate change on tundra plant ecology. Half of the plots are surrounded by open top chambers that passively warm the plots to simulate climate change. Each warmed plot is paired with a control plot at ambient temperature. These plots allow us to compare differences in traits such as phenology, and species composition and abundance between the warmed and control plots, and measure the effects of climate warming.

Open top chambers surrounding plots at Alexandra Fiord
The main focus of my field work this summer will be gathering data to study the relationship between shifts in phenology, reproductive success and species composition/abundance. To do this, we will be recording flower, leaf and fruit phenology of tagged plants in the plots, collecting fruits and seeds from these tagged plants and, new for me this year but conducted every 5 or so years, recording species composition and abundance in the plots using the point frame method.

Left: Recording phenology of plants in an OTC at Alexandra Fiord,
Centre: Germinating willow (Salix arctica) seeds at UBCs greenhouse as a measure of reproductive success,
Right: Point frame used to measure species composition and abundance
Over the winter we measured the reproductive success of the seeds we collected in 2018 by counting, weighing and germinating the seeds in UBC's greenhouse. In general seed weight was heavier for seeds from warmed than from the control plots and the heavier the seed the higher the germination rate.

Seeds collected from warmed plots (T) were significantly heavier than those collected from the colder control plots (C) for Mountain Avens (Dryas integrifolia), Mountain Sorrel (Oxyria digyna), Hairy Lousewort (Pedicularis hirsuta)
and Arctic Willow (Salix arctica) but heavier from control plots for Arctic Poppy (Papaver radicatum)
Germination rates were higher for heavier seeds for
Arctic Willow (Salix arctica) and Mountain Avens (Dryas integrifolia)
The Arctic Willow (Salix arctica) seeds collected from warmed plots had higher germination rates than Willow seeds collected from the colder control plots. In contrast, however, Arctic Poppy (Papaver radicatum) seeds collected from the colder control plots were heavier and had higher germination rates than Poppy seeds collected from the warmed plots. The Willow is taking over at Alexandra Fiord while the Poppy is seen less often in the warmed plots than in years past. These earlier results hint at some of the relationships between phenology, reproductive success and species abundance. This summer's field work will build on these early results to help quantify the relationships.

Arctic Willow seeds collected from warmed plots had higher germination
rates than seeds collected from control plots.
Arctic Poppy seeds collected from control plots had higher germination
rates than seeds collected from warmed plots.

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