July 18, Why do transect sampling? Options

[Leslie_Pierce]

July 18, 2005

My alarm goes off at 7:15 am. It’s time to talk with Earl Finkler! Brian and I are calling in via the satellite phone to KBRW (Barrow’s local radio station) to be guests on Earl’s morning radio talk show at 7:30. It’s pretty amazing to be able to call and talk from the Ikpikpuk River delta and Earl is an enthusiastic interviewer. He asks us what it’s like around our camp and we get to explain the snow goose project to listeners getting ready for work! I encourage listeners to go to the TREC website and look at the journal entries and ask questions. I don’t know if any of my students are listening to the show (it’s probably a bit too early for high school students, especially in the summer) but maybe someone will leave us a web message! Thanks, Earl, for having us on the show!

Here's the computer and satellite phone set up in my tent.


Today is our last day of walking and sampling transects. It’s sunny and windy, although at 52 F it is warmer than yesterday. We finish the last two transects on ABR island and are ready for our last kayak ride across the channel. We leave the boat on the bank of our island and head to camp and dinner! We’ll go back to bring the boat around and up through the little lake to our site when the wind dies down (hoping it does!).

Here I am ready to get in the kayak and head over to ABR Island for another day of transect sampling.


OK, so what will our transect sampling tell us? Ultimately, the data should reveal what types of plant communities are currently growing in certain areas, and what could grow there. Some of the sampled sites showed signs of grubbing and foraging and the soil core samples should show what types of plants were likely growing there in the past. The water content and salinity of the soils will be characteristic for each different plant community, whether it is dry graminoid, wet graminoid, or grazing lawns of sedge. The above-ground vegetation clippings will show the amount of biomass available to herbivores for each vegetation type and plant community.

Aerial surveys of the Ikpikpuk delta will be conducted in August and high resolution photographs will be taken along a representative series of transect lines. These photos will be useful in measuring the aerial extent of various vegetation types on the Ikpikpuk Delta. Together with the ground transect data, Brian will have a better understanding of the snow goose habitat in this area and the data will provide a starting point to determine the rate of vegetation change in this area.

After walking around these islands we saw obvious devegetation from early-season grubbing and grazing on all of the islands but to a greater extent on ABR Island. When the snow geese first arrive to this area, much of the habitat is under water. The available nesting sites, or high dry ground, seem to be surrounded by heavily grazed and grubbed areas. At that time of year (late May to mid June) there is not much green above-ground vegetation, so grubbing for roots and underground shoots is their only option for food. The snow goose parents don’t leave the nest for very long, as you can see piles of feces adjacent to nests, and foraging occurs very near their nest as well. As the goslings hatch and the family leaves the nest, the tundra is greening up, providing more forage. The surrounding area is also drying up as the water from snowmelt and flooding from the backed-up, iced-up river channels recedes, exposing more grazing habitat. Most of the snow geese broods that we can see now are off in the distance away from the nesting grounds, taking advantage of those areas.

So, the transects that we have sampled are providing preliminary data for characterizing the entire delta area, and for setting up future experiments. One experiment has already begun, the snow goose exclosure experiment that Brian set up last summer. Tomorrow we will sample the 48 plots for that experiment. I’ll tell you more about it tomorrow!

The midnight sun causes the tundra to glow behind my tent.