My life as a pollinator

For one month in Greenland, our most important scientific instrument was a paint brush.

Painting pollen onto Dryas integrifolia.

With our brushes loaded with pollen, we brushed the stigmas of hundreds of flowers, essentially acting as human pollinators. I am using this pollen-supplementation experiment to figure out if flowers could produce more seeds if there were more insects visiting flowers.

One flower we are studying is Dryas integrifolia, which is a butter-colored flower in the rose family (Rosaceae). It blooms early in the season, which is important for early emerging insects that are potential pollinators, including flies, bees, and yes, even mosquitoes.

Working with Dryas early in the season requires down jackets and a good attitude!

Once we were done painting, we waited for the flowers to close up and produce seeds. Dryas seeds are wind-dispersed, like dandelion seeds. So there was a narrow window of time in which we could collect the seeds before they flew away!

If Dryas produces seeds, it creates little twirls that remind us of unicorn horns or troll hair (right). If the stem aborts, it creates little white tufts (left).

Great news: today we successfully collected the last of the seeds! Other news: now I have thousands of seeds to count! [ Volunteers welcome 🙂  ]

Collecting the last of the Dryas seeds right near the margin of the Greenland Ice Sheet.

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A Gas Gizmo

What am I doing in Greenland this summer? I’m analyzing gas, pretty much. No, dehydrated camp food is not the most digestively soothing, but that’s not what I’m getting at (this time). I’m talking about my field research, measuring the carbon dioxide gas that is released from ground. To do this, we use a “gas analyzer” that looks like this:

The analyzer has two main parts: the white hat-like chamber, which we place on top of the ground to collect air that is being released from ground, and the analyzer bench, protected by a bright yellow plastic case, which measures the carbon dioxide in the gas that flows through tubes from the chamber.

When we put the chamber on the surface we can measure an accumulation of carbon dioxide gas as it is released from the ground. 

Effectively, we are watching and measuring the breath of the critters, microscopic organisms and roots in the soil. As shown above, during a two minute observation we see the CO2 levels rise from the concentrations in air (about 390 parts per million, or ppm) to nearly 500 ppm. The slope of the line represents how quickly the gas is being released from the ground. If we were to captured the breath that you exhale we would also see an increase in carbon dioxide!

In ecosystem ecology, this release of carbon dioxide from the soil is called “soil respiration”. It is particularly interesting to study soil respiration in the Arctic because the cold climate limits decomposition so lots of carbon has accumulated in Arctic soil over time. Furthermore, there are still a lot of questions about how this stored carbon will respond to climate warming — will the amount of stored carbon increase? or will soil respiration increase and perhaps cause an overall decrease in the amount of carbon in the soils? One way or another, this process has the potential to influence the global carbon cycle and future climate.

Did you know that soils breaths? There is a lot of life churning below our feet and we can measure it with a gas analyzer. Plus, the Arctic is a hot spot, so you can be sure that I will be busy all summer. Pretty cool, right? Bring up soil respiration at the next cocktail party, it will be a huge hit, I swear ;).

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