If you ask Rob and Jenny what they do for a living, they will jokingly tell you: "We count plants." But it's only partly a joke and it's just the beginning of what we do.
So... We count plants. We measure the high of plants. We measure the height of the tallest leaf or inflorescence (flower) of each plant. We record different stages in its growth like when it gets its first leaf, when the stigma appears, when the inflorescence buds. How do we do all this? We have several different experiments happening concurrently so we have to keep tabs on all of them and budget our time.
Point-framing: We are taking 10,000 individual point measurements on a one kilometer square grid. Our goal is to find our water plants are growing, how dense the area is, and create a three-dimensional profile of the grid because at most individual points there are between three and four individual plants that get measured, which means in this grid there will be between 30,000 plants measured! That's a lot of plants! This will be done again over the exact same locations two years from now and then two years after that to determine is there has been any change in ground cover over five years. This is being done in both Barrow and Atqasuk to compare the two sites.
Rob and Jenny set up the point frame apparatus that they will use to take 100 measurements of plant heights on the grid.
Jenny uses the measuring stick and calls out every plant she touches, it's height, it's species, and whether it's dead or alive. She does this until she reaches the soil. Sometimes each point will have five or six plants literally on top of each other while other time there may be only soil. Both of those case seem pretty rare. Most of the time, there are three to four measurements.
Jenny records Rob's point-frame measurements. Rob generally prefers point-framing and Jenny prefers recording; however, after a while they switch roles to stay focused.
Rob and Jenny have to pack up all the point-framing supplies and walk a hundres meters to the next plot...not so easy in the Arctic Tundra...where they will unpack and do it all again.
Growth Measures: We also are studying growth measure of plants by examining the heights and flowers counts of plants inside of one meter square plots in a wet and dry location in both Barrow and Atqasuk. At each location there are 48 plots: 24 control plots and 24 experimental plots. So there are 96 total plots in Barrow and an additional 96 in Atqasuk. The control plots are squares marked off by stakes and string. I'm currently in the process of re-stringing all the control plots. The experimental plots a hexagon-shaped and surrounded by 2-foot high fiberglass walls that are tied around the hexagon. These fiberglass walls are called OTCs, short for open-top chambers. All of the plots in both the dry and wett locations are reached by a "boardwalk," raised plank of wood that we walk on so we don't touch the ground there. Once a week we record the plant height, flower count, and stage or life for up to 15 plants in each plot. The is a small wood marker next to each plant but often time they are hard to see because we've been studying the same plants for fifteen years. We have made handmade maps of each plot so we know where to find each plant, just in case it feels like being elusive or doesn't want to be found.
There are forty-eight plots at the Barrow Dry Site. We reach each plot by using the adjacent board walk.
These are the plant markers used to show where each plant is that we are measuring. Sometimes they are hard to see, so we also have a notebook of maps.
Rob calls out measurements of plants in an experimental open-top container (OTC) plot at the Barrow Dry Site as Jenny records his measurements.
Rob teaches me how to do growth measures. Although it looks easy, it's pretty hard because you have to make sure you find the right plant, measure the tallest leaf, and not fall off the boardwalk!
Questions to think about:
1. Why do you think we have so many plots? Would one control and one experimental plot in each location be enough?
2. How many plots are there in total for growth measures?
3. Why do you think the OTCs are hexagonal shaped instead of a square?
4. The OTCs are equilateral hexagons. So how long would each side be in order to make the area one square meter?
5. Why do you think we walk on a raised boardwalk to reach the growth measures sites?
6. So I've described the experiment to you a bit. Based on what I told you, what do you think we're testing? (I put more on that tomorrow.)